REALISM - is your choice, but nobody else can deliver it.
If you are not seeking realism within your flight simulation you should skip everything after this first section. The files provided are carefully designed to be compatible with quite casual operation of the Fiat G.12 in ways that would be totally unacceptable in real life. You won't be punished with engine failures etc, if you decide not to comply with the realism available.
That way we can each take as long as we need to learn the skills of compliant flight without becoming frustrated by system failures that terminate attempts to comply.
This simulation is however designed to be used with all realism sliders full right and 'autorudder' off. The only mandatory realism is that we must slow the aircraft to 175 KmIAS to *extend* GEAR or FLAP. All other realism can be turned off via the MSFS realism screen. If you are interested in extracting all of the realism embedded in this product you should take the time to read through this entire tutorial once from top to bottom, before attempting to fly any version of the Fiat G.12. Do not expect to understand everything you encounter between here and the end. Just make a real or mental note to study the concept you did not understand when you feel ready to take on that new challenge.
If you are not interested in functional realism, but would like help to configure VCs correctly jump to the section CONFIGURING VC VIEW near the end of this tutorial.
FLIGHT SIMULATION.
Flight simulation = compliant operation of aircraft within a mathematically realistic virtual environment; is only achieved when we are able to deploy substantial acquired knowledge and skill to extract the realism embedded within the product.
In a (video) game the rules, the environment, and the skills required are just 'made up' by a 'game designer'. By contrast a simulation requires compliance with real world 'laws' of all kinds. A simulation is the opposite of a game. Neither the developer, nor the consumer, decides what the rules are in a simulation product. They must both learn what they are. That takes time and effort.
If we do not understand the real world rules, limits, operating targets, and procedures to be complied with we cannot conduct a simulation. Most of the relevant rules and procedures for flight simulation apply to all aeroplanes and are promulgated as real air traffic control procedures which may usually be downloaded from the web free of charge.
They are the rules that must be complied with by every (sim) pilot in every (sim) aeroplane. The developer must supply the aircraft and engine specific limits and operating targets for us to study and learn, but we are each responsible for downloading, studying, and then complying with all the rules of the simulation that apply to all aircraft, of all types, all of the time.
Real aeroplanes are designed to be compliant with the ATC procedures that were current at the time they were designed. The real dynamics of a vintage aeroplane may be incompatible with other (modern ATC speed controlled and radar vectored) modes of operation. However real commercial airfields must still offer real non radar departures, arrivals and approaches compatible with vintage era transport aircraft and so those real procedures remain available for free download by (sim) pilots.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
.......and tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V releases hosted at Avsim and elsewhere.
If we take it one step at a time, both the knowledge and the skills needed to achieve compliant operation of a real aeroplane, using real historical, (but still current), procedures within a mathematically realistic virtual training environment will gradually fall into place. Flight simulation is nothing less.
FREE TUTORIALS
Unless you have professional real world aircrew experience you will need to study (at least) the four free tutorials cited within this text. Understanding all of their content may take years not months. Real aircrew may need to study relevant parts of them in order to understand how to simulate vintage era navigation techniques and equipment using MSFS. Their generic content cannot be replicated in every release, but nevertheless applies to every realistic propliner release. Many of the terms which follow and within the tutorials may be obscure.
It is best to use tutorials on screen rather than printing them. They are intended mostly for non linear use. Format the font and size to your liking and use the word or phrase search function of your text reader to locate each occurrence of the obscure term or phrase in the relevant tutorial(s). Extract the information you need, when you need it. Treat them like a reference manual with an electronic search index. Read the surrounding paragraphs for each 'hit'. Searching for UPPER CASE occurrence will often take us firstly to the main HEADING beyond which the concept and usage are first explained. You may need to refer to (the included) real world ATC procedures and you will need the free Adobe Acrobat reader because those are in PDF format.
It may be a good idea to merge this text and the other tutorials into a single text document for word / phrase searching. The printed word is powerful, but not as powerful as instantly searchable text to reveal linked context and practical usage.
FIAT G.12 - MANY VARIANTS.
Please read Fiat G.12 History.rtf , (also in the G.12 common files folder ), before reading the rest of this text. Knowledge of the different historical variants of the G.12, their regional context, and the missions they flew is assumed in what follows. This tutorial will gradually explain how to simulate those real historical G.12 sorties in detail.
Phase by phase, and step by step, on screen handling notes are supplied as usual and you may also wish to print them. Unlike the available tutorials they are linear documents with a beginning, a middle, and an end. Extracts from the on screen handling notes are included below and explained in more detail.
In real life there were twelve varieties of Fiat G.12, all detailed within the 'Fiat G.12 history.rtf'. This MSFS release provides five different sets of flight dynamics and the associated handling notes for six different types of Fiat G.12.
Fiat G.12-CR used by NC-ALI and the Regia Aeronautica (R.A.) from 1941 to 1943.
Fiat G.12-T used by the R.A., HuAF, Luftwaffe, Co-belligerent Air Force, Corrieri Aerei Militari, A.L.I. and the post war Italian Air Force (A.M.I) from 1942 to 1949.
Fiat G.12-CA used by Alitalia from 1947 into 1948 and then the A.M.I. within NATO through most of the 1950s. These FD and handling notes also apply to the A.M.I. Fiat G.12-AV (Aula Volante = Flying Classroom).
Fiat G.12-L used by Airone, ALI-FR and the A.M.I. from 1947 to about 1952.
Fiat G.12-LB used by Alitalia from 1948 to 1950 and then the A.M.I within NATO throughout most of the 1950s.
Simulating the operation of five different versions allow us to understand the development of the G.12 from the first STOL VIP military transport delivered in 1941 to Alitalia commuter planes with a cargo pod delivered in 1948. The cockpit environment changes over time. New systems arrive. New engines arrive. Different operating procedures apply as the family develops and changes role.
Even within very complex flight simulation products such as this there has to be a limit to the goals of the product. We have not attempted to deliver the cockpit systems used by the A.M.I. within NATO through the 1950s. If we want to simulate use of modern ILS systems or NATO TACAN systems we should employ a different aircraft.
The goal of this product is to deliver better understanding of the last gasp of the vintage era of aviation history, before the classic era procedures adopted in the continental United States (CONUS) as early as 1932 were adopted everywhere. The G.12 family are from the vintage / classic transitional period when departure, arrival and approach procedures already involved point to point, beacon to beacon navigation, but navigation during the cruise phase was still based on manually updated GPS. This product allows us to simulate captaincy and pilot operated vintage era systems, procedures, and sorties in detail.
TREAT THEM LIKE REAL AEROPLANES.
The first thing to do is go and sit in the cockpit of each version and look around from the default eyepoint and eyeline, (to which we will be returned by pressing the keyboard spacebar if we ever become disoriented).
Make sure tool tips are turned on (options/settings/general). Use the mouse (and its mouse over function) to locate *and identify* all the gauges, switches and levers. If you do not understand what a particular gauge or switch does then attempt to locate an explanation in the supplied tutorials or within the MSFS learning centre (help/learning center). The bad old days of 2D Cockpit Views are long gone. No 2D graphic can deliver what we need to achieve flight simulation. The VC is the instructional graphic and is needed to deliver parallax compliant head up flight (see much later).
This tutorial will explain the usage of certain key gauges and controls, but for the most part we must behave like a real pilot encountering these aeroplanes for the first time and spend up to 20 minutes just locating and identifying where everything is before we turn anything on. Read this tutorial first to identify what to locate and to understand that the different cockpits have different systems.
After we have located and identified everything visible from the default eyepoint and eyeline of both P1 and P2 we must also study the 2D pop up panels, (views /instrument panel). In this simulation switches that are visible to the pilots, but were normally operated by other crew members, may not be clickable within the VC. They may only be clickable within the FE or WO pop up panels. In addition the poor ergonomics of vintage era cockpits will be imposed upon us. Vintage era aircraft did not have 'hands on throttle and stick' (HOTAS) procedures. If Pilot Flying (PF) wished to alter trim status himself, (often the case), he had to let go of either the engine controls or the yoke and reach out with that hand to operate controls positioned elsewhere. This simulation encourages us to 'reach out and touch'. Some controls which we expect to be operated by mouse click may actually require a (multiple) mouse drag. There was no mouse in a real G.12 and we encourage you to use the keyboard to control 'reach out and touch' functions such as trim.
However if you cannot tolerate the harsh reality that HOTAS procedures and systems lay far in the future it is possible to map any relevant FS functions to joystick buttons, however unrealistic that may be. So when we sit in the virtual cockpit for the first time we must not assume that everything we can see and can 'mouse over' to obtain a tooltip value is also a clickable mouse control'.
For instance as P1 or P2 we can see various 'controls' in the roof panel and we can use then to monitor status, but if they were normally operated by the FE then the 'clickable' version of those controls will be within the FE pop up sub panel. The pop up panels are configured to be used undocked outside the main FS window. MSFS is a 'Windows' product, not an ancient 'MSDOS' product. The different windows of the simulation should not be overlaid, but this product is deigned to makes that possible for those of you who insist on doing so.
In any event we must never turn anything on in an unfamiliar cockpit until we know where everything is, what everything else does, and how to control it. We must learn how to use the controls before attempting to fly the G.12. In the air is not the time to be wondering where the assigned heading needs to be bugged, or how to bug it. Learn which controls are clickable, which are dragable, whether you personally prefer to use the keyboard, and what the relevant keyboard short cuts are, while sitting on the ground.
GROUND OPERATIONS - part 1
Before engine start close the cowls. To start the engines manually we need to use controls available only to the Flight Engineer (FE). We must open the FE panel for manual starting. Automatic starting without recourse to sub panels will also work of course.
Once oil temperature exceeds 50 Celsius cowls should be fully open on the ground. Fully open cowls provide some additional cooling if there is a breeze or when we taxi. When we need to decelerate on the ground we may fully close the throttles, but it is bad practice to idle any of the relevant engines with oil pressure below 5C. All Italian cockpits confusingly use the abbreviation C to measure all types of pressure (in kilogrammes per square centimetre = Kg/Cm^2) as well as temperatures in Celsius = Centigrade .
G.12 crews normally used only the outer engines to taxi. During ground handling from either seat we may need to stick our head out of the side window to obtain adequate situational awareness. That is more comfortable and does not require goggles in some variants if the nose engine is not running. On the ground real world forward visibility was (is) otherwise limited, but 'adequate'. Flight simulation requires VCs with realistic sight lines and realistic blocking of sight lines. One of the most important differences between aeroplanes is how bad the cockpit design makes our situational awareness of the outside world from the inside looking out. Flight simulation isn't about staring at gauges. It's all about controlling our position and orientation versus the outside world, usually 'head up'.
PARALLAX
Flight simulation is about what we can see through the windscreen and reacting to what we see, or do not see, and where in the windscreen we see it. Head up flight is our reaction to the parallax relationship of specific parts of the airframe to the external environment. Without mechanical range finding devices humans are only able to measure angles *and range* using parallax. That is even more true during desk top simulation when the size of a building or conflicting aircraft depends mostly on user window size.
During flight simulation we must make constant use of parallax to measure both relative bearing (especially glideslope angle) and range. Simulation parallax must match real world parallax, (especially in pitch), else we cannot judge a glideslope or achieve complaint range offset from anything.
To achieve our operating targets in any aeroplane we must learn how to use the real parallax relationships. In one aeroplane we must place the wing tip over the runway when downwind to achieve complaint downwind offset from the runway and in another we must track a float down that same runway to obtain that same compliant pattern spacing. The developer must deliver those real parallax relationships because parallax is how humans judge range. Parallax must not be randomised. The real parallax relationship must be designed into the product and then we must learn how to use those real parallax relationships to achieve compliant operation.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
FRAMES OF REFERENCE
'Head up flight' uses two different parallax 'frames of reference'. Sometimes we must compare the parallax relationship between external aircraft structure outside the cockpit (like a float) and an object in the (real) scenery (like a runway), but much of the time we literally create a 'picture' which we literally 'frame' with the windscreen frame. Acquiring the skill to judge glidepath compliance, using only touchdown point placement within the 'picture' we 'frame' using the true scale VC windscreen frame, *from the relevant eyepoint*, is a key flight simulation skill, because it is a key real piloting skill. That skill cannot be learned, (or retained), if either the developer, or the consumer, randomise parallax relationships.
STEERING is all about PARALLAX compliance
After the vintage era of aviation history taxiways acquired centreline and radius markings. They are there for a reason. We must learn to target and control our parallax relationship to the markings, (or in their absence the taxi way edge). We must use whatever variety of steering we have chosen to employ to sustain a constant parallax relationship between a specific part of the aircraft structure and the markings (the external environment). The steering angle required is not random and is not 'as much as possible'. It is explicitly the steering angle (force) required to sustain the chosen parallax relationship between the piece of aircraft structure we chose as one 'object of reference' and the external environment 'object of reference'. All ground handling operations are 'head up flight' and learning how to use parallax to achieve complaint operation of the aircraft is the key to success.
We must keep one screw or rivet or some other 'chosen object of reference', which is part of the aeroplane, *and that is close to our default eyeline*, overlaid upon the taxiway markings (or edge) with zero parallax deviation. The angle the markings make to that object is never the point. We sustain zero parallax. We are in motion, but the taxiway is not a moving target.
Whatever object of reference we choose to use as our 'parallax sight' we do not need to 'pull lead'. We apply just enough steering pressure to keep the two parallax cues overlaid. The external object of reference is not moving. The 'steering force' required to achieve and sustain that real world parallax compliance is highly specific, not random.
Most flight sim enthusiasts make the huge mistake of never learning to operate aircraft 'head up' and rely forever on gauges and 'head down' flight to 'measure' everything and for every conceivable kind of navigation. Most flight sim enthusiasts never learn how to use parallax to navigate or control their energy state in 4D and forever experience huge difficulty keeping aircraft under control because they have never learned to judge the relationship of the aeroplane to the scenery using only the appropriate parallax frames of reference.
In many cases that is due to the parallax relationships in many /most releases being randomised, (by the developer or the consumer), as though MSFS were just a children's video game in which the designer and the consumer are free to invent the rules.
ANSALDO SVA5 - head up flight - parallax tutorial
To understand how to operate aircraft head up it is essential to learn in simple aeroplanes. The skills of parallax control learned during head up flight in simple aeroplanes can then be successfully transferred to head up ground handling in complex aeroplanes. The best available free tutorial concerning use of head up parallax techniques is within the Ansaldo SVA 5 release available from Avsim and elsewhere. If you have never mastered the skills of head up flight, using real world parallax compliance techniques, you should start there before attempting to operate more complex aircraft in a compliant way.
GROUND HANDLING - Part 2
We may need to slide our eyepoint further left and right than the default P1 and P2 eyepoints to stick our head outside the cockpit in any taildragging aeroplane, because that was (is) necessary in real life. Only VCs have that capability of course. Taildragging aeroplanes need to be operated from virtual cockpits to understand real world operating techniques even more than other kinds of aeroplane.
Who CAPT should order to taxi the aeroplane depends on whether the taxiway turns will be mostly right hand or left hand. Pilot Flying / Pilot Not Flying (PF/PNF) allocation is not random between P1 and P2. It is just one more careful captaincy decision in our decision making cycle. To ENTER the P2 seat from the P1 seat we must press CTL + SHIFT + ENTER and to go BACK to the P1 seat we must press CTRL + SHIFT + BACKspace. There is no reason to keep the nose engine running after landing.
Even with the nose engine shut down when operating the CR, T and CA we must pull down our goggles before we stick our head out of either side window since our eyepoint is aft of the wing mounted airscrews. In the L and LB we no longer need flying helmets and goggles provided we keep the nose engine shut down for 'head out' ground handling because the cockpit side window has moved ahead of the wing mounted screws.
We must always start the nose engine in time to attain oil temperature = 50 Celsius before take off. If necessary we run the (nose) engine up briefly against the brakes to obtain oil = O = Olio = 50 Celsius before take off. In all variants we set 40% cowls before line up. Micro management of the engines is the job of our virtual Flight Engineer (FE). As pilots in a complex multi role cockpit we micromanage only boost, rpm and cowl status.
The real cowl controls are on the central pedestal between the pilot's seats where they are hard to see and use during desk top simulation, (but where the real FE could also get at them easily in real life). For our convenience during simulation those controls act only as a status repeater and we can control the cowls by mouse clicking the cowl status gauge on the P1 panel. Of course it is still possible to control them, (or other systems in this simulation), with the keyboard or assigned joystick buttons. That makes it harder to set the standard values cited in the on screen handling notes, but in all cases we choose how to control the simulation. The consumer control interface we have provided is carefully designed to help us to avoid becoming overloaded with extraneous tasks while we strive to achieve and sustain all the more important captaincy and pilot handling targets in the supplied handling notes as well as the real departure, arrival and approach procedures.
Flight simulation is the learning and tenure of the skills required to comply with real ATC procedures. It is not the ability to turn knobs A to C until a given reading is achieved on gauge D. Scientists have been able to train molluscs to do that.
In this complex and realistic simulation the cowl flaps really do increase engine drag, as well as moderating engine temperatures, so we must (learn to) use them in a compliant way.
The landing lights also function as taxi lights and are fully controllable. The real cockpit controls are not duplicated we must (learn to) use the keyboard to control them during night sorties (Options/controls/assignments).
TAILWHEEL LOCK
During taxi operations we leave the tailwheel unlocked. After we have lined up we lock the tailwheel. The locking handle is between the seats where it is hard to see. The real pilots could just feel for it. We must do the desk top simulation equivalent using the keyboard to toggle the tail wheel lock with SHIFT + G (one handed).
Locking the tailwheel to aircraft heading before take off helps to prevent uncommanded yaw due to crosswinds, torque, and p-factor while the tailwheel is down and in frictional contact. We do *not* want the tailwheel to move away from aircraft heading while we are using rudder to steer. We leave the tailwheel locked to aircraft heading after take off. We need it locked for landing, but we cannot line up if we lock it before we line up.
WHEEL STEERING versus RUDDER STEERING
In real life multi engine aircraft with tailwheels are steered mostly by differential thrust augmented by differential braking. This is possible, but quite difficult to replicate within MSFS because most flight sim enthusiasts lack multiple throttles. Within MSFS wee must rely on wheel and rudder steering more than in real life. Most flight sim enthusiasts struggle terribly with this because they fail to differentiate between wheel steering and rudder steering. To line up, (or just taxi), we must use proportional wheel steering carefully limiting how much we move the yaw controls so that wheel angle is always that required to sustain our current head up parallax target.
Wheel steering is the opposite of rudder steering. A rudder gives maximum turn rate at maximum deflection angle. Wheels don't. Wheels just skid when excessive steering angle is applied compared to current vehicle velocity. Yet most flight sim enthusiasts fail to behave accordingly, even though in real life they can ride a bicycle and steer a car while resisting the temptation to believe that max wheel angle is correct for every turn at every vehicle velocity. Consequently most flight sim enthusiasts quickly lose control of aircraft with realistic ground handling encoded in their flight dynamics. Most flight sim enthusiasts induce skidding of the only steerable wheel at every turn by applying excessive wheel angle versus current vehicle velocity and turn radius, as though they were trying to steer a tiny boat with a massive rudder, rather than an massive aeroplane with a tiny wheel. Most flight sim enthusiasts make no attempt to moderate steering force to sustain their head up target parallax.
The target parallax is only visible from the relevant eyepoint. We cannot moderate rudder steering force correctly, or steering wheel angle correctly, during flight simulation if we cannot see the target parallax relationship. MSFS is not a radio control model simulator. The models do not weigh just a few pounds. The developer writes inertia code to make their inertia match a mass of many thousands of pounds, whose steering depends on a few square inches of rolling, not skidding, rubber contact. Real aeroplanes do not respond to being treated like tiny radio control models. Small applied steering angles are required to prevent skid. Tight turns in massive high inertia vehicles must be initiated at low vehicle velocity.
When we are operating an aeroplane we must (learn to) control our heading during ground handling based on whether *we* have connected wheel steering or rudder steering to our steering inputs. They don't work the same way!
Trying to use a flight simulator as though it were a radio control model simulator works badly for good reasons. The skills to be learned are different. The control techniques needed are different.
'Realistic' flight dynamics exist to measure pilot error, and to illustrate the consequence of that pilot error. Demanding cheat modes in forums to incorporate into aircraft.cfgs so that all aeroplanes have only boat steering is a poor choice compared to understanding the pilot errors that cause loss of control. We must learn how to steer correctly with wheels, and how to steer correctly with a rudder, after making and implementing the appropriate ground handling captaincy choice, while operating the aircraft from the eyepoint which delivers the vehicle to environment parallax target with which we must comply.
Else we have no way to determine the correct steering force to apply to comply with our head up parallax operating targets. Only if we are steering from the relevant eyepoint, using the relevant parallax target, do we have sufficient situational awareness that we have lost control and have induced a wheel skid. Whether we lose control by application of excessive wheel angle or excessive velocity is semantic. We must (learn to) constrain our velocity so that modest steering angles deliver parallax compliance.
FLAPS - and gear.
Use of FLAP 1 for take off is normal at all weights and in all versions. Like many other Italian aircraft FLAP status is indicated with lights. They are in the roof panel and are part of the variable geometry status gauge whose lights also disclose GEAR status. The tailwheel does not retract so we only ever see two greens when the gear is down and locked. The next light in the flap status gauge sequence does not illuminate until we have run another ten degrees of flap. The vintage era flaps run slowly.
The crew of the G.12 could however run the flaps to any defined angle and the real operating manuals specify hardly different angular settings for take off and landing at different weights from different runway lengths. This is not very practical in MSFS as it leads to flap code with a vast number of stages. I am sceptical that the real crew did more than run the flaps until the relevant lights illuminated, unless the runway was truly critical, which would have been vary rare. The flap switch is between the two pilot seats, but in this simulation it is best treated as a secondary status indicator. We should use the keyboard to vary both wing geometry and gear geometry. The real operating switch between the seats is marked with the standard settings for take off, approach and landing (15, 20, 45).
The normal flap settings are not 10/20/30/40 as shown on the (real) primary status gauge in the roof panel. Those are just the flap angles that trigger the cockpit lights in turn. During operations at normal weights, from normal contemporary length runways, take off is performed with one lamp illuminated (stage 1), the approach is flown with two lights illuminated (stage 2) and all four lights should be illuminated for landing (stage 3). In this simulation pressing F8 will not invoke full flap. It will invoke normal landing flap.
The flaps are fragile and *all* stages are subject to a profile drag limit of 175 KmIAS.
The gear motor is also weak. We must not attempt to travel the gear while imposing abusive profile drag in excess of 170 KmIAS. The bay doors are not moving in the same direction as the gear. They do not suffer the same inhibiting or additional profile drag to their movement. Attempts to operate the gear with abusive profile drag (IAS) applied will cause gear malfunction and may cause the gear to foul the bay doors whilst partially extended. We should operate the gear using the keyboard and only while IAS <= 170 KmIAS (= 92 KIAS).
A TORNADO of PROFILE DRAG.
Even flight simulator enthusiasts who have grasped that IAS measures the abusive profile drag they are applying to a fragile structure often fail to associate the values they see on the ASI with their real world understanding of hurricane and tornado force winds. At some level flight sim enthusiasts understand that even a category 1 hurricane = 64 KIAS starts to rip moderately well built structures apart. By the time we reach 98 KIAS we are abusing the airframe with F2 (Fujita scale) tornado drag forces. F2 tornadoes can do very bad things to even well engineered structures. Yet for some reason most FS enthusiasts think that even 98 KIAS is not much force to apply to a fragile structure, or a thin flap hinge, or a vintage motor which must force those fragile structures out into the F2 tornado of abuse they are imposing.
At some level we all know that F2 tornado force drag can do really bad things to well engineered structures, but most MSFS users completely fail to associate 98 KIAS on the ASI with the destructive force of an F2 tornado. No one should be amazed that extending flaps might require us to reduce the force on the motor, the flaps, their hinges and support brackets, below F2 tornado force before trying to extend them. Aeroplanes and their fragile moving parts do not have exemption from the laws of nature. We must (learn to) act accordingly.
TAKE OFF.
As explained in G.12 history.rtf the Fiat G.12 was designed to have STOL capability in military use. It does not actually require flap for take off, but it helps to get the tail up during the take off roll, and we can rotate *firmly* almost as soon as we manage to get the tail up. The IAS at which the tail comes up varies with weight and flap deployment. Once it is up, it is safe to rotate. Vr self resolves. We can sense Vr from aircraft behaviour. The elevators have limited effectiveness on the ground because profile drag over the tailplane is still very low and so reversing its camber with the elevators to induce negative lift at the tail consequently has limited effect.
Before take off we must trim the elevator tab = 4 cabrata in all versions to retard post unstick acceleration and promote initial climb. This is the reverse of the normal requirement, but is necessary because we must retract FLAP before reaching the safe structural limit of 175 KmIAS. If there are obstructions immediately adjacent to the runway higher cabrata settings may be used and flap retained whilst climbing at only 170 KmIAS over the immediately adjacent obstruction.
***************************************
Take Off Phase: (G.12-CR )
LINE UP
BRAKES = ON
RPM = MAX
THROTTLES = FULL
BRAKES = OFF
YOKE = FULL FORWARD to raise tail
TAIL UP - wait 2 seconds - ROTATE FIRMLY
POSITIVE RATE OF CLIMB
GEAR = UP
ACCELERATE = 170 KmIAS
FLAP = UP
ACCELERATE = 210 KmIAS
Call for Climb power
***************************
We clear any carb ice before take off. We do not deploy carb heat, (reducing power), during take off, (or during final approach when we may need TOGA power to go around). We can ignore carb heat altogether when flying the G.12, but if we decide to apply it manually it should be used only when OAT between 0 Celsius and +5 Celsius and boost below 0.8 C. After applying carb heat we should check the carb temp gauges to verify that the system is working correctly. If we applied carb heat correctly as above carb temp will be equal to, or just above, OAT and will be in the + 1 to +10 Celsius range. Carb heat should not be applied continuously by the G.12 pilot. It should be applied periodically when OAT is just positive and the engines are throttled. If carb temp exceeds 10C remove the heat. We need carb heat most during the arrival and approach phases as we reduce boost and descend into air warm enough to contain enough moisture to be a problem.
If the G.12 variant in question has an autopilot we must check it is OFF before take off.
The use of rudder trim for take of is trickier for two reasons. Some real (multi engine) pilots like to feel and counteract the relevant forces with neutral trim applied because that makes it easier to recognise and deal with a sudden (partial) engine failure, whilst others like to fully trim the relevant forces out before take off. We can do either.
The locked tailwheel down condition does not endure and is therefore irrelevant. It is the enduring tail up state that we must trim for if we decide to trim for yaw at all. The yaw trim required is different with / without locked tailwheel resistance to yaw. The aeroplane will always swing as the tail lifts. This is partly due to gyroscopic precession, but mostly loss of yaw resistance from the locked tailwheel.
However Fiat A.74 engines and Bristol Pegasus engines have opposite screw rotation. The Fiat engined CR, T and L all have clockwise screw rotation, whilst the CA, AV and LB with Pegasus engines all have counter clockwise screw rotation. Consequently the early and late models yaw and roll in opposed directions when more power is applied, or screw RPM is varied. We need to think carefully which engines are installed. The exact rudder trim required varies with crosswind vector and so the handling notes only indicate that the trim required is sinistra or destra according to engines installed.
(INITIAL) CLIMB - targets and limits.
Before flap retraction we must prevent the aircraft from reaching a dangerous profile drag of 175 KmIAS, while climbing over immediately adjacent obstacles . After flap retraction our operating target is acceleration, not climb. We must instead *prevent climb* while we accelerate to 210 KmIAS as quickly as possible. This may take some time. It will take longer in later heavier versions, especially if they also have a cargo pannier.
To climb efficiently we must maximise the Lift to Drag (L/D) ratio of the wing and the propulsive efficiency of the airscrews. To climb efficiently, (as opposed to urgently), we must first accelerate the aircraft to the 'right side' of its drag curve. To climb efficiently we must minimise total drag, not maximise lift. Aeroplanes are climbed using surplus power from their engines, not surplus lift from their wings. Surplus power is the power not being consumed to offset our total drag.
Each old Fiat engine in the G.12-CR / T / L can deliver 820hp for up to two minutes for TOGA at sea level. We must not retain TOGA power for more than 120 seconds after throttle up and we must achieve 210 KmIAS during those 120 seconds. We use the panel clock to measure those 120 seconds from throttle up. After flap retraction we must prevent climb accordingly. The heavier we are, the slower we accelerate, and the harder we must work to prevent climb after flap retraction. We must reject TOGA power within 120 seconds from throttle up.
The earliest interim production G.12 (the CR) had a maximum take off weight of just over 28,000lbs, and with three engines the CR was theoretically capable of very high rates of climb, even without use of METO power, always reducing directly to normal climb power after rejecting TOGA. However after take off, at light weights (in any variant), since we have no pressure cabin, we must reduce power to (significantly) less than the available climb power in order to *restrain VSI to no more than 3.5 metres per second*.
This is especially important during airline operations when our passengers may be frail and may react especially badly to rapid change of air pressure. Providing oxygen to them has no relevance. It is air pressure change that must be managed with care. During casualty Evacuation (CASEVAC) operations from Africa and the Ukraine we must restrict VSI even more, never exceeding 2.5 m/s. The physiological limits of elderly civilian and wounded military passengers are far below the structural and power limits of the G.12. Most flight sim enthusiasts consistently fail to limit rates of climb and descent appropriately in unpressurised aircraft. In real life there are other considerations than the power available or the structural limits of the aeroplane.
Once we have accelerated the aeroplane to the 'right' side of the drag curve the early variants need swift reduction of power *below the available normal climb power setting*, to prevent excessive VSI. In the early variants of G.12 METO power is invoked only in the event of engine failure, so in their handling notes we see;
ACCELERATE = 210 KmIAS
Call for Climb power
***************************
METO power - use only after engine failure:
C = 1.0
RPM = 2400
COWLS = 40%
****************************
Climb power:
*DO NOT EXCEED 3.5 m/s*
210 KmIAS
C <= 0.9
RESTRAIN C to achieve target + limit above
RPM = 2300
COWLS = 40%
On reaching 4000 metres
Call for Econ cruise power
****************************
As time progressed new variants were certificated to take off at higher weights and ventral cargo panniers were added. Both increased drag and diminished climb rate. The post war 'Lungos' were certificated to depart at over 34,000lbs and the operating procedures and priorities changed. The later variants have poor rates of climb in Climb Power when departed with full fuel. When flying the later versions we must think carefully before we reject METO power for climb power, but we should not retain METO power once we are safely above all *down range* obstacles.
These aircraft belong to the vintage phase of aviation history. The ICAO instrument flight rules (IFR) did not apply, (in the relevant region and timeframe), and there was no minimum rate of climb for IFR compliance. Unpressurised passenger aircraft have a VSI limit but in the vintage phase of aviation history they have no VSI target. Consequently vintage era autopilots could not control VSI. They controlled pitch to control IAS at constant power to achieve compliance with the operating targets of that phase of aviation history.
During simulation it is an error to use vintage era systems and equipment to pursue modern era (or even classic era) goals. The vintage era systems are optimised to deliver compliance with vintage era procedures. In order to conduct a vintage era simulation we need to understand what constitutes vintage era compliance.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
In the handling notes for the underpowered G.12L we see;
ACCELERATE = 210 KmIAS
Call for METO power
***************************
Obstacle Clearance phase - METO power:
C = 1.0
RPM = 2400
210 KmIAS
COWLS = 40%
Above all obstacles
Call for climb power
****************************
Climb phase:
VSI <= 3.5 m/s
C = 0.9
RPM = 2300
220 KmIAS
COWLS = 40%
On reaching 3000 metres
Call for Econ cruise power
****************************
There is no VSI target. There is no VSI hold mode within any relevant AP. At high weights in the post war Lungos we will need METO power to avoid obstacles in the departure, and climb rate using climb power afterwards will be very modest. In any event vintage era compliance requires us to achieve an IAS target avoiding a VSI limit. The Sperry AP, which came into use in Italy around 1947, has a pitch seek mode which we must (learn to) use to sustain our IAS target, (or we just hand fly and trim to sustain our IAS target).
COMPARISON COMPASS, DEVIATION COMPASS and vintage AUTOPILOTs.
All varieties of G.12 have a flux gate compass. The G.12-CR of 1941 has no AP. The one we will be flying has a Patin comparison compass which is a daughter / slave of the flux gate compass in the tail.
As PNF, (after studying the GPS plot as updated by WO), we decide and bug the assigned heading which PF must sustain using (mouse clicking) the rotating outer knurled ring of the centrally mounted, German Patin patent, unobscured arc, comparison compass.
In the CR and T we also have a German patent Askania deviation compass (ROTTA) which is in turn a daughter / slave of the Patin comparison compass.
.......see tutorials within the Savoia Marchetti S.73 V2 and fiat G.18V hosted at Avsim and elsewhere.
.......see also 2008 Propliner Tutorial from www.calclassic.com/tutorials
All varieties of G.12 have a ship type back up magnetic compass mounted in gimbals between the seats. The cockpit gyros will not precess unless subjected to abusive bank angles. They are daughters/slaves corrected by the flux gate mother/master compass in the tail.
The G.12-T delivered from late spring 1942 has an inferior Microtechnica daughter /slave obscured arc twin barrel comparison compass based on US Sperry patents and German Siemens technology. This in turn drives a limited function Italian Microtechnica AP. The Microtechnica AP offers HDG hold achieved using a rudder servo, but it has no HDG or pitch seek. If we attempt to use the rudder servo of a Microtechnica AP to seek an assigned heading it will succeed but only *very* slowly. It is designed to deliver assigned heading hold. It has *no* pitch hold and *no* pitch seek capability.
As PNF we use the *right* hand control knob and the upper barrel of the obscured arc Microtechnica comparison compass to bug the heading we assign to PF *whether or not the Microtechnica AP is switched ON*. However as PF we use the Askania deviation compass (ROTTA) to sustain the heading assigned by PNF using the Microtechnica comparison compass.
.......see tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V hosted at Avsim and elsewhere
.......see also 2008 Propliner Tutorial from www.calclassic.com/tutorials
The post war CA, AV, L and LB all have Sperry Blind Flying Units (BFU) connected to Sperry three axis APs imported from the U.S. To make life easier for less experienced flight sim enthusiasts, in this simulation they retain their MS default cheat mode of HDG seek and capture. However the post war manufactured G.12s have no Askania deviation compass. As PF we must rely solely on the Sperry obscured arc comparison compass. Its deficiency compared to the pre war German unobscured arc Patin compass technology in the G.12-CR, but denied to US pilots, will become clear during use, especially when making turns through large angles to intercept approach courses.
As PNF we use the *left* hand control knob and the upper barrel of the obscured arc Sperry comparison compass to bug the heading we assign to PF *whether or not the Sperry AP is ON*.
Any AP must be OFF before take off and vintage era APs should be OFF before we transition from the arrival phase to the approach phase.
AUTOPILOT (AP) IAS HOLD is via PITCH SEEK
If you are not familiar with vintage era autopilot systems it is best to avoid invoking them at all. If you have never learned to use the Microsoft implementation of the real Sperry AP you should take the Sperry AP equipped G.12-L up to altitude and study usage of that AP system as an extended training exercise in its own right until you fully understand the different limitations of the Microtechnica and Sperry AP systems. In particular study at length how to use the pitch seek mode of the Sperry AP to sustain your target IAS during the obstacle clearance, climb, and descent phases of each flight.
In the vintage phase of aviation history there was no VSI target and no pitch target. Pitch seek is the means by which IAS hold is achieved. We must (learn to) IAS hold in climb and descent using Sperry vintage era pitch seek techniques.
VSI hold did not exist. Remember too that altitude hold does not exist and has no relevance during cruise. The semi circular and quadrantal rules do not exist, (in this region at this time). After establishing initial cruise at the cited altitude the aircraft is allowed to drift up at constant pitch as fuel (mass) reduces. There are no *assigned* altitudes in the en route phase. There are no airways to follow. During the cruise phase we are always 'off route' using 4D area navigation, not 2D airways navigation.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
TRIMMING - 'torque roll'
Real (transport) aeroplanes do not bob around like a leaf in a gale unless the weather is adverse and they are subjected to at least moderate turbulence. Real aeroplanes have substantial inertia and are not easily perturbed from their equilibrium state. Real aeroplanes are quite easy to hand fly *provided they are in trim*.
While the AP is off we don't fight the aeroplane, we trim the aeroplane. We trim it to sustain complaint IAS with elevator trim and we trim it to sustain compliant *assigned = bugged* heading with rudder trim.
(Transport) aeroplanes have both high pendulum stability and high dihedral stability. Three airscrews, creating three powerful vortices, all rotating in the same direction, tend to roll the G.12, which then causes it to yaw. The more thrust we generate the more it tends to roll off course, but the higher the profile drag (IAS) over the dihedral the better the dihedral resists the tendency to roll. The rolling tendency is worst at high thrust and low IAS so we need most rudder trim under that condition. Take off is the worst case and even climb power at climb IAS will 'require' non zero rudder trim. The forces can be held with stick and rudder pressure, but the idea is to trim out those forces using trim to achieve compliant IAS targeting and compliant assigned heading targeting. The direction we need to trim is different with Fiat and Bristol engines. Use your keyboard and assign single (not multiple) key presses for rudder trim control.
Provided we apply compliant power the designed dihedral angle will prevent uncommanded roll during cruise. The carefully designed in stability and inertia of transport aeroplanes makes these issues much easier to cope with than in smaller aircraft with the same total power. If we still find engine torque and aircrew p-factor too difficult to cope with we should move the relevant realism sliders away from full right. This simulation otherwise assumes all realism sliders full right and autorudder off.
CLIMB RATE versus CLIMB GRADIENT
Every flight we simulate is divided into distinct phases and each phase has specific operating targets and specific operating limits which we must achieve *before we exit that phase*. If we depart light we must not exceed 3.5 m/s, but we will usually suffer a poor rate of climb anyway in the 'Lungos'. If there are obstacles in our departure we retain METO power. We only retard to Climb power once we are above the *down range* obstacles. We have no VSI target. We only have a VSI limit. We have power targets and IAS targets to comply with from the handling notes. Before and after the GPS cruise phase we have tracks and altitudes to comply with from the real world ATC procedures we have downloaded.
In the heavier post war Lungos our profile drag (IAS) target for normal climb is 220 KmIAS not 210 KmIAS, but only after we are above all down range obstacles. A profile drag of 210 KmIAS gives us a superior climb gradient. whilst a profile drag of 220 KmIAS gives as a superior climb rate. As captain we are constantly deciding whether to alter aircraft energy state urgently or efficiently and the correct choice is not random.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
The final versions of the G.12 had different engines with more climb power and could reject METO sooner since they had adequate rates of climb in Climb Power. When flying unpressurised passenger aircraft with high power to weight ratios (e.g. Fiat G.12-CR) we must concentrate on not causing physiological damage to our passengers. In any (non combat) aircraft we should *not* retain METO power throughout the climb. Once we are clear of down range obstacles we retard to (no more than) Climb Power. Overheating engines with excessive and prolonged friction (RPM), and wasting fuel as fast as possible, via excessive boost from the superchargers, by application of excessive throttle opening, is never our operating objective.
REJECTING CLIMB
If simulating a date before 1947 we continue climb to initiate cruise at 4000 metres; else if after 1946 we continue only to 3000 metres before rejecting climb. We route around, not over, higher terrain. The rules concerning operation without passenger oxygen within unpressurised passenger cabins changed and became more restrictive soon after WW2.
ANTI ICE SWITCHES
Design cruise altitude compliance is all very well, but we must take icing into account. The CRs delivered in 1941 had no anti ice or de-ice capability and were assigned to relevant routes. The series production Transporto introduced both liquid airscrew (ELICHE) anti icing and thermal airframe (CELLULA) anti icing. Post war CA commuter planes retained airscrew anti icing, but had no airframe anti icing or de-icing of any kind, and they did not last long in airline service. The AV also had no airframe anti icing. That omission was rectified in the LB.
The anti ice switches are located on the FE panel. Since they are preventative anti ice systems, not reactive de-ice systems they may be turned on all the time in MSFS. We just have to be aware which variants do not have which systems and choose cruising altitude versus weather during each decision making cycle accordingly.
MULTI CREW OPERATIONS
After we reach the appropriate legislative altitude for the date and location we are simulating we apply Econ(omical) cruise power and begin to monitor headwind vector and descend again if necessary (subject to terrain). The semi circular cruising rule did not apply in the vintage phase of aviation history.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
Our virtual flight engineer (FE) will operate most engine systems including the oil cooler shutters and the supercharger turbine controls to match what we are doing as PF. We must control boost, RPM and cowls. Substantial cowl opening will be necessary with high RPM applied when we also have low natural profile (cooling) drag ( = IAS). Our virtual FE supplements the engine cooling due to cowl opening by other means. Micro management of engine temperatures is his job, not ours, in a multi crew cockpit .
We must not get bogged down in micro managing the roles of other crew members. Our goal is compliant operation of the aircraft in accordance with real ATC procedures, not micro managing engines. We are not simulating single crew operations when we simulate the operation of a complex four aircrew propliner, and we must not pretend that we are required to do everything that needs to be done in an airliner cockpit. It is an error to pretend that the other three crew have all died and that we must manage all the systems in complex cockpits. Simulation of single crew aircraft operation and multi crew operation should be quite different experiences. The airline or military pilot of the vintage era was not a jack of all trades.
As pilots we will open the cowl flaps to increase engine drag to carry the excess heat of high RPM (= high friction) at low profile drag (IAS) away. We open the cowl flaps to add profile drag. We must remember to close the cowl flaps for economical cruising else our velocity (TAS) will be constrained causing fuel, range (and airline profit) to be squandered. The cowl flaps must be closed in descent else we risk shock cooling the engines. We must open them again after the arrival phase and before we reduce IAS for the approach phase.
Obviously some departures, (e.g. proceeding immediately over the sea), may have no obstacle clearance phase. The on screen handling notes follow a logical linear sequence, but on some flights it may be appropriate to omit some phases. Departing over the sea, (or in many other 'flat' or 'descending' terrain circumstances), we proceed directly from the take off (power) phase to the climb (power) phase and on those departures we never invoke METO rpm or boost, even when heavy.
The five different versions of the G.12 in this release have different operating targets and they have three different types of engine, burning two different types of fuel. Variety of flight simulation experience is so much more than just visual variety. The more real procedures, operating targets and limits we incorporate the more varied and interesting our operating experience as we struggle to meet them all in real time, but we must not become bogged down in micro management of other aircrew roles in a multi crew environment. Realistic captaincy, piloting and 4D navigation will be challenge enough.
THE ENGINES
Most Fiat G.12s (including CR, T and L) were powered by the Fiat A.74 engine. This was a medium power radial designed entirely by Fiat and available with different Fiat designed superchargers according to design cruising level. Designed to compete with the superior and earlier Gnome et Rhone GR14 Mistral Major the A.74 was foolproof rather than excellent and was also much favoured for use in pre war and early WW2 fighter aircraft of the Regia Aeronautica. Its compact design with two rows each of seven short cylinders offered a small frontal diameter which reduced drag in the cruise, but much more importantly made it reasonably easy for the pilot to see around and over the nose cowling during the approach.
We need virtual cockpits to replicate those harsh realities. Pretending that it is just as easy to maintain situational awareness on approach, or on the ground, in a trimotor, compared to a twin like the DC-3, misses the whole point of bothering to simulate the more difficult operation of trimotors. The simulation must deliver the problem so that we can learn the skills of coping with the problem.
However use of narrow diameter two row radials limited maximum power. They tend to overheat the rearmost row of cylinders quickly, when compared to big long cylinder single row radials like the Bristol Pegasus, which was built in Italy under licence by Alfa Romeo and used in most Savoia trimotors, and the post war Alitalia G.12-CA, G.12-AV and G.12-LB. The Fiat engine also had slightly worse than average specific fuel consumption.
Operation of the Fiat engine differs considerably from operation of the Bristol engine in the Fiat G.12LB because it also uses different fuel. The Bristol Pegasus engines manufactured under licence by Alfa Romeo before, during and after WW2, which powered the G.12CA and AV used the same pre war quality fuel as the Fiat engine, which also limited their maximum power.
In all versions of the Fiat G.12 (manifold) pressure is measured in Kg/Cm^2 abbreviated to C (Carburatore). One Kg/Cm^2 (C) is *not* the same thing as one Atmosphere (Ata). It is a lower (manifold) pressure. Unlike the Fiat A.80 engines in the pre war Fiat G.18 Veloce the Fiat A.74 may be briefly and safely boosted to more than one atmosphere (= zero boost).
The very reliable post war Bristol Pegasus 48 designed to power the Short Sandringham was designed to use 100/130 Octane AVGAS and could run at significantly higher C and significantly higher RPM than pre war engines which ran on pre war fuel (even after WW2). The Fiat and Alfa Romeo engines used pre war / pre surrender Italian 87 Octane AVGAS, (even after the surrender), which limited their TOGA power significantly, and their other high power settings to a lesser degree. The use of engines designed in Britain causes real Italian operating manuals to have strange manifold pressure values when converted to C. Sometimes PSI boost in the British manual was rounded in conversion, sometimes not. That is replicated in the supplied handling notes.
ENGINE RATINGS - AUTO MIXTURE - POWER COMPLIANCE
The engine ratings quoted in the 'Boys Book of Wonderplanes' rarely convey any coherent information about real life power availability. The 'Boys Book of Wonderplanes' will incoherently inform us that the pre war Fiat engine was more powerful than the post war Bristol engine.
The fourteen cylinder Fiat engine was rated at 770hp using high speed gearing of its turbine to compress the air just above 4000 metres, but it had to be run autorich to manage that, and it could not run its turbine at high speed at low level in thick air. The nine cylinder Bristol was rated at only 720hp using its high speed turbine to compress the air just above 4000 metres.
Who cares!
What matters in propliners and analogous military aircraft, such as bombers, is how much power we can generate safely;
1) to cruise continuously with a lean mixture (usually at high altitude using HI turbine gear ratio)
2) to take off briefly using a rich mixture (usually at low altitude using LO turbine gear ratio).
What the 'Boys Book of Wonderplanes' often does is to give us the useless information concerning rich mixture at high altitude in HI gear. Many such books display no consistency from engine to engine quoting (1) for one engine and (2) for another, often according to a propaganda agenda in an original document or other book the latest 'author' is only plagiarising.
For this reason before we attempt compliant operation of aeroplanes in MSFS we must always pay careful attention to the information provided in the on screen handling notes which should always explain both situations.
For the Fiat powered G.12CR/T/L the handling notes begin;
***********************
The three 770hp Fiat A.74 RC42 engines drive constant speed airscrews. They have automated mixture controls and manually applied carb heat controls. Superchargers sustain that rated power up to 4200 metres. Each engine can deliver 820hp for up to two minutes for TOGA at sea level.
***********************
But for the Bristol powered G.12LB we see;
***********************
The three 720hp Bristol Pegasus 48 engines drive constant speed airscrews. They have automated mixture controls and manually applied carb heat controls. Superchargers sustain that rated power up to 4400 metres. Each engine can deliver 1010hp for up to five minutes for TOGA at sea level.
***********************
Now we understand what is possible with autorich mixture in HI blower at high altitude and with autorich mixture in LO blower at low altitude. During take off the '720hp' Bristol provides 23% more power than the '770hp' Fiat and if necessary for 150% longer. Those three extra minutes and 23% more power from the 'less powerful' engine make a huge difference if we suffer an engine failure just after a max gross departure at the higher post war Lungo weight of 15,500Kg and with the extra drag of a cargo pannier.
Our virtual FE and real world automated systems will manage the mixture for us. Powerful engines from the late 1930s onwards had automixture controls. Manual control of mixture to balance temperature and fuel flow in powerful aircraft was still possible, but not strictly necessary, so we won't be micro managing the role of the real FE. We will concentrate on simulating the roles of CAPT, PF, PNF and WO during each decision making cycle of the sortie. There is no NAV. The GPS plot is updated by WO and then PF's heading is assigned by PNF.
.......see tutorials within the Savoia Marchetti S.73 V2 and fiat G.18V hosted at Avsim and elsewhere.
.......see also 2008 Propliner Tutorial from www.calclassic.com/tutorials
MAX CRUISE - SIGNIFICANT HEADWINDS - POWER COMPLIANCE
We still know nothing about the power we can generate in safety whilst cruising the aeroplane. We must cruise with weak (autolean) mixture (applied by our virtual FE). In the Fiat G.12 we will normally cruise in HI gear blower, (also selected by our virtual FE), whether with Fiat, Alfa Romeo or Bristol engines, since in the absence of significant headwinds we will normally, (subject to icing), commence cruise at 3Km or 4Km depending on date and applicable legislation.
Now we must study the max cruise section of the handling notes.
For the Fiat engined G.12CR we see;
****************************
Max Cruise:
Use to battle headwinds
C = 0.9
RPM = 2000
COWLS = 10%
Plan 930 PPH
Yields 194 KTAS at 4000M (FL131)
****************************
While cruising our virtual FE will invoke (auto)lean mixture. In propliners of this complexity our fuel planning is always for autolean engine running. We must not demand more than 0.9 C or 2000 RPM with an autolean mixture of 87 Octane AVGAS because that would cause the engine to run rough via premature detonation of the low quality fuel and that would overheat the engine to (exhaust valve) failure. We must not generate more than about 600hp (per engine) however severe the headwind we may need to battle. Maximum safe available power with an autolean mixture is called Max(imum) cruise power.
Max cruise is a compliant power, not a target velocity.
During cruise the risk of causing physiological damage to our passengers by applying high boost to the engines disappears. The air pressure in the unpressurised cabin will be almost constant whatever engine boost we apply. We can apply more boost when battling headwinds than during climb, but with an autolean mixture we must use fewer RPM to restrain heat in the (autoleaned) engine.
High RPM = high friction = bad way to use a reciprocating engine.
Our virtual FE applied autorich mixture during climb so that we could maximise the efficiency of the screws, running them at high RPM whilst they were advancing through the air at low velocity (TAS). In cruise our velocity (TAS) is much higher and we need to run the screws at significantly lower RPM to optimise their propulsive efficiency.
Maximum THRUST (TRACTION) is not the same thing as maximum POWER.
It is always our job to manage thrust independently from power in aeroplanes with constant speed airscrews. Most flight sim enthusiasts never grasp this. No complex piston engine aeroplane has an automatic gear shift. They are all manual shift. We must always use the RPM levers to control thrust (traction) independently from power (fuel flow) in the same way a manual shift stick is used independently from throttle in a European car.
Too much throttle at the wrong RPM just causes wheel spin in terrestrial vehicles and screw slip in aeroplanes. Yet many flight sim enthusiasts try to fly from New York to Los Angeles using high or maximum RPM (car analogy = still in low gear) wondering why performance is terrible and they run out of fuel. High thrust ( = good traction) is not the same thing as high power. At the wrong RPM more power just induces wheel spin = screw slip. RPM compliance is vital during flight simulation
If we encounter a 'significant' headwind we must respond in a compliant way. Both boost compliant and RPM compliant. We desperately need to increase fuel burn to increase range when we encounter significant headwinds, but we must not use more than max cruise power to increase our fuel burn to battle headwinds.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
With Fiat A.74 engines running on 87 Octane AVGAS we must not drive fuel burn beyond about 310 pounds per hour (PPH) per engine (x 3 engines = 930 PPH) when battling headwinds else we will induce premature detonation of that low quality fuel, which was still the only fuel widely available right across Italy until 1948.
Simulating operation of these aeroplanes with modern low lead fuel is pointless. To allow flight sim enthusiasts to understand them and their place in the timeline of aviation history the developer must load the fuel that was available when they were in daily use, not the fuel that a museum may use to hobble vintage or classic era aeroplanes around the modern air show circuit. How they need to be operated and what the operating targets are is a function of the fuel quality loaded (by the developer) to match their original roles and original fuel availability.
When we generate max cruise power in a Fiat G.12 we must also open the engine cowls 10% to add engine drag for cooling even though we have high natural profile (cooling) drag (IAS) flowing over the engines. We must also adjust RPM to sustain high thrust (traction) at the revised boost.
Realistic flight dynamics (FD) contain all of those relationships, but *we* have to extract them. They do not extract themselves. MSFS is not a scripted cartoon to be watched. It is a simulation with real weather dependent compliant output targets which we must (learn to) achieve using real world compliant inputs learned from handling notes.
Realistic FD without matching realistic on screen handling notes are useless. We need to know what inputs we must apply to create each real fuel octane and mixture compliant power setting else all we can ever experience is random thrust applied, driving the aeroplane to a random and unrealistic energy state, achieving random payload v range potential, as weather varies. We monitor the weather carefully and continuously and during each captaincy decision making cycle we decide what power to apply and what altitude to cruise at.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
EFFICIENCY or URGENCY?
Each phase of flight has a correct applied manifold pressure (boost), controlled with the throttles, and a correctly matched engine / screw RPM, controlled with the RPM levers to sustain target traction. Target traction is not a constant. During take off we desire very, very, *inefficient* traction. The situation is urgent. We desire every last pound of thrust, however much fuel is burned to create it. To the contrary during long range cruising (LRC) we desire highly efficient traction instead. Those two conditions don't just happen. We must (learn to) mix and match RPM to boost, (traction efficiency to fuel burn), based on the urgency of the situation. To do that we must (learn to) evaluate the urgency of the situation.
Both economical (max nil wind profit) cruise power and maximum (safe) cruise power require intermediate traction efficiency versus vehicle velocity. Traction efficiency does not take care of itself in piston engined aeroplanes. There is no equivalent of an automobile automatic gear gearbox making (usually dumb) RPM selections for us versus throttle applied. We must study handling notes and (learn to) make compliant RPM selections. Compliant RPM selection is *not* always intended to increase traction efficiency. Efficient traction is often the wrong traction. Minimum cost and maximum profit are not the same economic function, and neither relates to minimum legally required safety criteria.
Specific (mean) headwind vectors require specific C and RPM selections. They are not random choices. We must learn what they are and then we must undertake the role of captain and decide when to apply them. The supplied flight dynamics, however realistic, can only ever link our inputs to simulation output. If our inputs are unrealistic and randomised the simulation can only ever be unrealistic and randomised too, however much realism is encoded and embedded within the supplied flight dynamics. The flight dynamics exist to test our skill and our knowledge of how to operate the specific aircraft and the specific engines in the current weather conditions a specific grade of fuel. Realistic performance requires us to achieve compliant operation, else the supplied flight dynamics quantify and demonstrate our pilot error.
OCTANE RATING
With post war Bristol engines we can generate around 23% more power (fuel burn) for take off, and in emergency, using a rich mixture of 'high octane fuel', but we do not have the same power ratio advantage for max cruising with (auto)lean mixture. 100/130 octane is called that because it 'equates to' 130 Octane fuel when autorich is applied during climb, but 'equates to' only 100 Octane fuel when autolean is applied during cruise.
To obtain the same power output as we obtained from fourteen cylinders in a Fiat A.74 engine we need to run the nine cylinder Pegasus 48 with significantly more boost and significantly more RPM. That is only possible once 100/130 Octane AVGAS is available for upload *everywhere* we need to upload fuel.
In real life aircraft cannot go where the fuel (grade) they need to uplift is not available. It may never become available in many places and at different major airfields it becomes available at different dates in different locations. Aviation needs low quality engines using low quality fuel in different places at different times. Destinations along the domestic commuter network may not have high quality fuel (yet). The situation for military command structures is even more complicated than that. Many piston engines are therefore 'dual fuel'. They have different sections in the same manual which explain how to achieve complaint operation using different fuels. We will revisit dual fuel compliance later.
With only nine cylinders in a Pegasus each cylinder runs hotter, and we need more cowl flap opening to restrain it to similar operating temperatures. Two different engines do not produce the same output using identical inputs. We must (learn to) use detailed handling notes which explain how to mix and match the power settings of boost and RPM and manually applied cooling drag used to battle headwinds, and also for normal economical (profitable) cruising, else we cannot obtain realistic results from our simulation. The final production variant (G.12-LB) requires very different max cruise *inputs* for every power control parameter to deliver hardly different target power and thrust (traction) output.
****************************
Max Cruise: (Fiat G.12LB)
Use to battle headwinds
C = 1.03 (zero PSI boost)
RPM = 2250
COWLS = 20%
Plan 1000 PPH
Yields 190 KTAS at 3000M (FL98)
****************************
With a Pegasus 48 running autorich = 130 Octane we can generate 23% more power than with a Fiat engine running on 87 Octane. With Pegasus 48 engines running autolean = 100 Octane we can run continuously at zero boost. That allows us to generate around 660hp per engine in safety, (only about 10% more than a Fiat A.74 running on 87 Octane). The screw is geared differently and to achieve compliant traction we must run at different engine RPM.
NIL WIND RANGE depends on DRAG
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
The short fuselage light weight G.12CR built in 1941 induces less drag from the same wing and has no cargo pannier. It is faster using lower fuel burn and therefore has more range when loaded with the same mass of fuel in nil wind conditions. The post war CA Lungos are less able to battle headwinds despite their extra power. The greater the mean headwind the greater the range advantage of the early series, low drag, short fuselage, no pannier aircraft, but note that both of these tiny, over complex, VIP and later commuter planes are at least as fast as big load shifting twins like the widebody DC-3.
The 1948 G.12LB can carry much more payload than the 1941 G.12TR, but with the same fuel it has less range. Drag was higher in the Lungos and they cruised slower as the commercial value and utility (payload delivered versus fuel used) of these niche market aircraft was slowly and over expensively improved.
We cannot benefit from 'realistic' flight dynamics, unless we have detailed handling notes, or until we learn how to use them realistically. Only then can we discover the real differences between one aeroplane and another, or even different versions of the same aeroplane with different engines, or in some cases just the same engines using different quality fuel at different dates, or in different parts of the world where the best fuel is not yet available, or in a different military command chain with different fuel logistics and priorities.
FIAT G.12-CA
Alfa Romeo, (just like Nakajima in Japan, or Walter in Czechoslovakia), had been manufacturing Bristol Pegasus and/or Mercury engines under licence since the mid 1930s. Many Italian and Japanese combat aircraft of WW2, used in combat against British and American forces, were powered by British engines with American airscrews. All varieties of G.12 had US patent Hamilton Standard airscrews manufactured under licence by Fiat. Perhaps that is why the Fiat engines had 'American' clockwise rotation at the prop shaft.
What Italy and Japan (initially) lacked was high octane fuel, because the oil superpowers withheld it. The Axis powers 'needed' to seize access to oil fields and refineries by invasion. Italy and Japan had excellent engineers who could design high powered engines, but there was no point. Italy and Japan were refused access to high octane AVGAS by the nations who would later join forces to fight them when they decided to seize access to high octane fuel by force.
Whilst there was insufficiently widespread access to 100/130 Octane AVGAS across onshore and offshore Italy, the old Alfa Romeo AR128 version of the Bristol Pegasus, used in the wartime S.M.79bis torpedo-bomber transport, mated to the same very modest supercharger, designed for low altitude anti shipping strike, had no disadvantage compared to later versions of Pegasus designed to run on a fuel that was still not locally available.
The G.12-CA is powered by those wartime Alfa Romeo Pegasus engines designed to run on pre war 87 Octane AVGAS. Despite having only nine cylinders those engines could briefly produce more TOGA power than the Fiat running rich, but not as much as a post war British Pegasus with a post war British supercharger designed to run on 100/130 AVGAS. So in the handling notes for the 1947 vintage G.12-CA we see;
>>>>>>>>>>>>>
The three 860hp Alfa Romeo 128/RC18 (Bristol Pegasus) engines have automated mixture controls, and manually applied carb heat controls. Superchargers give rated power up to 1800 metres. Each engine can briefly deliver 930hp for take off below 1800 metres. This engine has constant speed airscrews which can be feathered.
>>>>>>>>>>>>>>
RANGE into a HEADWIND depends on POWER
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
On average significant headwinds become more and more likely as design cruising altitude increases. Designed to operate in the anti shipping strike role at low level, the ability to develop significant power in autolean to combat headwinds had not been a priority during design of the AR128/RC18. In autolean it could run continuously at only slightly more boost than the Fiat and with only nine cylinders it developed less Max cruise power (only about 530hp per engine).
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Max Cruise:
COWLS = 20%
C = 0.92
RPM = 1950
Plan 800 PPH
Yields 166 KTAS at FL98 (3Km)
****************************
Since the Fiat G.12-CA now always dragged a ventral pannier around, its max cruising velocity was poor and its ability to battle headwinds was poor. It was constrained to lower altitudes and I suppose that is why airframe anti-icing was deleted. Alitalia knew they needed something better, and quickly. The CA lasted for only a year in airline service and in reality was much better suited to the low level aircrew training role (Aula Volante = Flying Classroom) with the post war Italian Air Force .
DUAL FUEL ENGINES
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
Engines designed to run at low boost and low rpm on low quality fuel do not (usually) have the cooling and lubrication systems needed to run at higher boost and RPM with better fuel, even when it becomes available locally. A later mark number of that engine is required with superior cooling and lubrication.
However that superior later mark of the same engine can (usually) make use of the inferior fuel, *provided it is operated in compliance with the operating criteria of the older mark of the same engine*
We could choose to simulate operation of a 1948 vintage G.12LB after loading 87 octane fuel by using the 1947 vintage G.12CA handling notes. In this case that would be pointless because dynamically the experience would be identical to flying the CA. The CA and LB have almost the same shape, mass and drag. The LB just had a better post war engine, with a better supercharger, better cooling and better lubrication, able to benefit from better fuel. This made it worth re-introducing airframe anti icing.
The reason we have bothered to develop and deliver multiple versions of a single design with different engines, running on different fuels, with appropriately different systems, is so that flight sim enthusiasts can experience the process of historical change, version by version, and learn from that process. The differences just disappear unless very careful attention is paid to the differences in the handling notes, and they only really show up if the different versions are operated in varying weather using compliant power. Adequate power to battle one weather system is inadequate power to battle another, whether the problem is ice, or headwind vector, or both.
VINTAGE PHASE OF AVIATION HISTORY
We cannot benefit from realistic flight dynamics if we operate the aircraft in atypical ways disregarding its historical usage. Its design evolved to match operation in the navigation and ATC environment of its particular regional environment and times. These aircraft were not operated in accordance with the modern ICAO Instrument Flight Rules (IFR). Airways barely existed across southern Europe, even in the airline timeframe of the Fiat G.12LB, and the semi circular cruising rule did not apply. These are all propliners from the vintage phase of aviation history which persisted across parts of Europe for up to a decade after WW2. In other words they were *designed and operated* to national criteria (the vintage era), not later international criteria (the classic era).
The Fiat G.12 operated within the vintage era ATC / GPS radio navigation infrastructure. It always carried a wireless operator (WO) to update the GPS plot manually. WO triangulated current position and marked it manually on the glass or plastic overlay of the GPS chart before handing the overlay to Pilot Not Flying (PNF). Each decision making cycle PNF then decided what heading to assign to Pilot Flying (PF) before handing the GPS plot back to WO for the next slow manual update of the GPS. If an aircraft captain happens to be a pilot he chooses whether to be PF or PNF minute by minute.
The Fiat G.12 did not fly 'point to point' from one 'radio beacon' to another in the en route phase. The Fiat G.12 was not based in the United States and was not designed to meet US 'classic era' federal aviation regulations and procedures (FARs). It did not have navigation equipment for use in a classic era communications, command and control (C3 = ATC) infrastructure. It could not be operated by just two instrument rated pilots like a DC-3 in the USA. The design, operation and crew complement of a G.12 could only match the local aviation infrastructure.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
ECONOMICAL CRUISING - POWER COMPLIANCE - FUEL PLANNING
The post war Italian airlines were struggling to avoid bankruptcy and without huge subsidies they could not. CTA = Airone and ALI did not survive. As legislation concerning carriage of passengers without oxygen became more restrictive after WW2 the post war Italian airlines increasingly initiated cruise at no more than 3000 metres and target cruising velocity (TAS) was reduced in the thicker air.
C = 0.875
RPM = 2000
COWLS = CLOSED
Plan 660 PPH
Yields 155 KTAS at 3000M (FL98)
****************************
As a general rule engine cowls for radial engines are designed so that economic cruising (Econ cruise power) generates enough natural profile drag (IAS) over cowled radial engines to need no augmentation of engine drag via opening of cowl flaps. Only long range cruising at lower IAS, or max cruising at high power, normally requires us to impose additional engine drag. There are exceptions.
CTA (Airone) obtained the most cost effective version of all, (the G.12L), With up to 22 passengers to pay for the fuel they believed they could afford to cruise fractionally faster than their domestic competitors, but the 22 seaters were now horribly underpowered and CTA were soon in financial difficulties. They were quickly taken over by ALI who would also only survive for a few more years. Each mission or individual sortie we decide to simulate has specific goals, and wasting as much fuel as possible, as fast as possible, is never one of them. We should load only as much fuel as we need for the route; (see Fiat G.12 history.rtf); using the fuel planning values in the supplied handling notes.
The TAS yield quoted is for Design Mean Cruise Weight, at Initial Design Cruise Altitude, in the International Standard Atmosphere (ISA) weather conditions, using autolean mixture. Within MSFS, (because we have no access to worthwhile forecasts of winds aloft), we must always fuel plan for that case. Actual yield will differ with weight and weather. That is why we load specific fuel reserves and during the captaincy decision making cycle react only to specific weather conditions deemed significant in relation to the aircraft in use.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
The cost of using three large engines and four aircrew to transport no more than 22 passengers in the L, no more than 18 in the CA, and at most 16 in the LB on domestic commuter / cargo flights was a very heavy burden on post war Italian airlines. They had to economise. Remember none of the post war Italian airlines used these interim post war commuter aircraft for their prestige international services. Those airlines which the allied powers allowed to regain international route licences used far superior Avro Lancastrians and widebody Douglas DC-3s, along with the, (to be released next), Fiat G.212 widebody to fly those prestigious and high demand services. The post war Fiat G.12 commuter planes flew feeder routes to those international routes.
Once the post war narrow body G.12s passed to NATO, (the post war Italian Air Force), mostly for VIP transport use, I expect they squandered fuel and operated at up to max cruise power and / or initiated cruise at 4000 metres much of the time regardless of the weather, but the longer these aircraft were in airline service the more the fuel burn target was reduced and less fuel airline captains were allowed to load for the same route, even as both take off weight and drag rose.
Most flight sim enthusiasts fail to fuel plan, load far too much fuel, suffer poor aircraft performance, and never notice, (let alone record), how much fuel they squander. Fuel that the real captain was not allowed to load.
We cannot learn the captaincy skills of diversion decision making if we load random fuel.
In real life most military and commercial sorties are fuel critical and have specified route fuel and specified reserves. One important goal of flight simulation is to learn how to maximise the payload carried, (with legal fuel reserves), from A to B, down the real route, over (or around) the real mountains, flying the real world departure, arrival and approach procedures, in real and varying weather. Learning how to limit the fuel realistically, and how to operate the aircraft skilfully with less fuel, to maximise the payload, is a key flight simulation skill.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
ECONOMICAL cruising = PROFITABLE cruising.
The desire to simulate the operation of airliners is a desire to learn the skills of profit maximisation. Those skills are quite different to the skills and techniques used to maximise range with a given payload in a bomber , and quite different again to the skills required to maximise the patrol endurance of an anti submarine aircraft or fighter on CAP. Maximum profit is associated with much higher cruising velocities, but maximum profit it is always associated with a specific target velocity (TAS) not a random number derived from random inputs. With reciprocating engines economical cruising is the opposite of long range cruising and must be conducted with very different engine inputs at very different altitudes.
Although the G.12 had been designed for ultra long range trans Atlantic operation it never undertook ultra long range sorties in practice. However its original long range capability was useful to the RA during casualty evacuation (CASEVAC) missions from Africa. All wartime supply missions were really CASEVAC missions promulgated as something more palatable. There were always more wounded in need of evacuation to major hospitals than the RA could cope with. A 'supply' mission 'to Africa' was really a CASEVAC mission 'from Africa', yet maintaining supplies of AVGAS in Africa was paramount.
We should always load enough fuel for the entire round trip before we set off for Africa. The supply we can carry south will be very limited, but the fuel burned en route allows more casualties to be loaded before we return north *without demanding any fuel in Africa*. The much more numerous G.12T sorties to / from the Ukraine uploaded enough fuel for both legs in Romania, which was the original source of Axis oil supplies suitable for refining to 87 Octane AVGAS or better.
Only once we learn the techniques of economical cruising, measuring how much payload we delivered, versus how much fuel we used to deliver it, can we begin to understand why one type of airliner survived for decades on every continent, whilst another with an equally good, (or better), safety record sold badly and disappeared from every airport within just a few years. Contrary to the opinion held by fanboys of aviation far more military and commercial aircraft should have been cancelled before they ever left the drawing board, but some that appear to be bad out of date designs are well matched (best fitted) to the locally available fuel (logistics) and the regional command and control (ATC) infrastructure constraints.
CRUISING - ALTITUDE CHOICES - ANTI ICE - SIGNIFICANT TAILWINDS with wartime cargo
The operational ceiling of the Fiat G.12 is well above the safe altitude for unpressurised passenger transportation without an oxygen supply to the cabin. The full specification Transporto delivered from late spring 1942 had comprehensive anti icing capability and was compatible with prolonged flight in moderate icing conditions, based on the original pre war expectation of mostly extreme range trans Atlantic G.12 operation, and wartime reality of continuous cruising to the Eastern Front beginning at 4Km, (in the absence of significant headwinds).
We will not be micromanaging anti icing systems in this simulation. We will only simulate delegation of that task by turning on one or both anti ice systems for airframe (cellula) and airscrew (eliche) anti ice protection in variants which have either capability. Then we will let the virtual FE get on with his job while we get on with managing the decision making cycle and achieving our multiple and concurrent operating targets in compliance with real world ATC procedures.
When hauling only cargo to the Ostfront G.12T crews of the R.A., HuAf and Luftwaffe might don their oxygen masks to commence cruise at 5Km (FL164) if there was a significant tailwind to be ridden. The older and slower the aircraft whose operation we choose to simulate, the more likely we are to have a significant headwind or tailwind, and the more we need to understand and apply relevant 4D navigation strategies during our captaincy decision making cycle.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
Conversely CASEVAC operations (whether returning from the Ukraine or Africa) in unpressurised military aircraft should be conducted at the lowest practical cruising altitude to maximise oxygen saturation within the casualties. Flight simulation is most interesting when it is simulation of a specific sortie with specific historical goals.
ARRIVAL PHASE - en route DESCENT
Our descent IAS target is always the IAS which was the cruise IAS yield achieved with the correct power applied for the current headwind vector during the last decision making cycle.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
During descent we do not have a VSI target. Again we only have a VSI limit which is -3.5 m/s (-2.5 m/s for CASEVAC from much lower altitude). We plan ToD accordingly. We retain cruise RPM and adjust C accordingly. If necessary we use a holding pattern to achieve outbound and inbound compliance. This is frequently necessary when our departure airfield, or destination, is adjacent to a mountain range which we must cross at an altitude far above airfield elevation.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
****************************
Descent phase:
*DO NOT EXCEED -3.5 m/s*
Retain CRUISE RPM
Target prior cruise IAS
DO NOT EXCEED 350 KmIAS
*AVOID SHOCK COOLING*
C reduce @ 0.1 per minute
C => 0.5 (*MIN*)
COWLS = CLOSED
****************************
Big powerful aero engines with powerful turbines attached are expensive to buy and even more expensive to maintain. They must not be shock cooled by sudden closure of the throttles at Time of Descent. The boost must be eased down in small steps and must not be reduced below 'mid' values which keep the engine warm and the oil circulating . IAS is profile = cooling drag. It must not be allowed to rise unconstrained causing shock cooling. ToD must be planned accordingly.
The arrival phase begins at Time of Descent (ToD) and only ends when we have met all of the targets specified for commencing an approach. The arrival will often include a period of holding in a holding pattern. Arrival planning including ToD planning versus the Initial Approach Fix (IAF) arrival criteria disclosed by the real world approach plate is the same as for any other propliner.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
.......see also tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V hosted at Avsim and elsewhere.
ARRIVAL PHASE - HOLDING
Within the G.12 on screen handling notes of (e.g.) the Fiat G.12T we see only the aircraft specific requirements;
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Holding phase:
FLAP = UP
RPM = 1850
C = as required to achieve
210 KmIAS
COWLS = as required
****************************
We must achieve 210 KmIAS before we cross the Initial Approach Fix (IAF) whether or not we need to hold. If we screwed up our ToD planning, or we failed to control our IAS during descent, and do not yet meet the criteria for commencing an approach, then *we need to hold*. The holding pattern is where we get out operating targets back under control.
TURN CO-ORDINATOR RATE 1 TURNS
After the IAF all of our turns must be rate 1 turns, carefully applied using our turn co-ordinator, and if we allow our profile drag to exceed 210 kmIAS our velocity (TAS) will also be excessive requiring large bank angles to achieve rate 1 compliance. Failure to comply with our arrival IAS target or failure to achieve rate 1 compliance may cause our mismanaged holding pattern to collide with the obstacle we are using the holding pattern to avoid.
We do not commence an approach, (proceed from the arrival phase to the approach phase of any flight), before we have complied with all of our arrival phase operating targets. We must use handling notes to learn what they are. In addition if our destination is just the other side of the local mountains we need to enter the hold and descend in the hold even if we already complied with all of our other arrival phase operating targets.
Holding patterns are neither irrelevant, nor a nuisance. They exist to facilitate the safe climb and descent of aeroplanes clear of obstructions. Holding patterns existed before ATC and they may exist where there is no ATC. They do not exist to impose approach sequencing delays, even though ATC may use them for that purpose too.
Most flight sim enthusiasts just ignore the real holding patterns and wander around in dangerous random 4D flight paths, (or allow Microsoft ATC to vector them in dangerous random 4D flight paths), or for some reason expect to be able to climb /descend directly too or from the mountains without using the real holding pattern which exists for that purpose, both inbound *and outbound*.
The outbound case is identical. We do not exit the obstacle clearance phase for the en route climb phase until we have met all of the altitude restrictions of our real world departure (downloaded from the web). We will often need to climb QFG in a published holding pattern to achieve our departure phase altitude targets.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
During the arrival phase in any G.12 we need to achieve 210 KmIAS before we cross the IAF. We cannot know what altitude we must cross the IAF, or how to plan ToD accordingly, unless we know where the IAF is! We need to download the real approach plate!
Holding and most of the instrument approach is flown FLAP UP and GEAR UP at 210 KmIAS. Our energy state targets and variable geometry targets barely relate to the real type of approach which we have downloaded from a real ATC agency and clear ourselves to simulate after we reach the IAF. The arrival procedures we fly prior to the IAF will not usually depend on the subsequent approach from the IAF. They will depend on our direction of arrival to the IAF and the obstructions in the real arrival procedure . At most locations those are explained on the approach plate, not the STandard ARrival (STAR) plate. The absence of a STAR (for free download) does not mean there are no real world arrival procedures (for free download).
A large part of any sortie is planning the sortie. If we fail to plan we plan to fail. Making up some random nonsense, or auto generating some random nonsense, is not the same thing as flight planning. Flight planning requires us to discover what constitutes compliance in the real world so that we know what our operating targets are during our next (flight simulation) sortie. More to the point the real procedures are always achievable. Random nonsense, and auto generated nonsense, may be unachievable (in vintage aircraft) and the extent to which we fail to achieve it is of no consequence. The extent to which we were able to comply with the real world procedures is measurable and of consequence.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
.......see also tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V hosted at Avsim and elsewhere.
CREW ROLES - PERIOD AVIONICS and APPROACH REALISM
All G.12s were equipped to fly instrument arrivals and approaches, but the CR lacked a Lorenz Beam Indicator (LBI). Most G.12Ts (including some RA, but no HuAf aircraft) eventually had LBIs.
The post war airliners also have LBI, also configured as LOC/DME receivers, but in which the DME needle indicates target metric glideslope height (*not altitude*...*not distance*) in metres. In a metric cockpit the horizontal LBI needle delivers metric 'height should be' cues versus a 3 degree glideslope similar to those delivered by a radar controller during a Surveillance Radar Approach, but it is *not* a glideslope needle and is *not* a 'kilometres to go' needle. It is a 'height should be' needle.
Think very hard about the difference between a needle that depicts our height (Classic era Bendix ILS) and a needle that only depicts 'height should be' (Vintage era AEG LBI).
.......see metric LBI tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V releases hosted at Avsim and elsewhere.
During the war terminal navigation was more usually by PF interpreted obscured arc goniometer (Radio Goniometric Indicator = RGI), tuned by WO, and with the MFDF aerial oriented by WO. All varieties of the G.12 have pilot goniometers, even the G.12LB which also has an unobscured arc radio compass (ADF).
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
Just because pre war, wartime and post war aircraft have a very small D/F loop, (see G.12CR MDL), with limited range, used only for terminal guidance, mounted inside a tiny egg shaped streamlined housing, does *not* imply that the aerial inside is automated and that the system is ADF.
It implies only that the tiny loop inside the 'egg' is used mostly for short range terminal approach guidance. All except the last five Fiat G.12s had only manual DF driving a pilot radiogoniometro whether equipped with a large loop for dual HFDF and MFDF navigation or only a tiny manual loop in an egg housing, used mostly for terminal MFDF guidance. ADF was not introduced into the G.12 family until Alitalia deployed the Lungo Bristol in 1948. Housing manual D/F loops inside low drag 'egg' housings happened long before ADF was available in most countries and almost certainly everywhere including the United States. An 'egg' housing does *not* imply that the crew have ADF.
The WO of the G.12LB (only) could connect the old pilot goniometer to the ADF1 tuner with the new radio compass (ADF) connected to a new ADF2 tuner. In the G.12 they cannot be connected the other way round so we must choose carefully which NDB we tune to which device using the WO pop up panel.
First delivered in 1948 the Lungo Bristol was the only variant able to locate any kind of en route radio intersection using two needle techniques. Note however that all G.12s from the Transporto onwards can locate radio intersections during terminal guidance navigation, (locate a Lorenz beam passing through an NDB used as an outer marker), since they have both a VHF LBI needle and an MFDF goniometer needle. Thus all except the CR flew, (and we can simulate), what the contemporary RAF and USAFE called BABS (Blind Approach + Beacon System) approaches.
.......see tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V hosted at Avsim and elsewhere.
.......see also 2008 Propliner Tutorial from www.calclassic.com/tutorials
When flying the CR and T be careful not to confuse the Askania deviation compass (ROTTA) with the pilot goniometer. They look very similar.
At major airports the approach to the instrument runway will almost always be a VHF Lorenz Beam Approach rather than a goniometer or ADF only MF approach. There may be co-located DME, or not. If there is no co-located DME the horizontal 'height should be' needle of the LBI will 'park' at the end of its swing. Vintage era navigation gauges did not have OFF flags. Note that the LBI has a MKR light which will be triggered by any MKR. During straight in approaches to low minima we will often use it during missed approach decisions depending on what we have seen and identified (or not) at the Middle MKR of the LBI approach.
.......see tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V hosted at Avsim and elsewhere.
Where neither Lorenz Beam (LOC or LOC/DME), nor NDB approaches were available the Fiat G.12 flew ZZ approaches during and after the war. Some airfields with Lorenz (LOC) beams also offer ZZ approaches to other runways which may be the landing runway today. An undocked by default pop up panel with a VHF (NAV.1) radio compass is provided in each relevant version to allow ZZ, (including but not limited to VDF), approaches to be flown using (mostly airfield sited) VORs as the ZZ QDM source within MSFS.
The 'extra gauges' pop up panel should *not* be deployed unless conducting a ZZ approach. The extra gauge represents our WO relaying the QDM provided by the approach controller during a vintage era ZZ approach.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
In aircraft of this date the avionics receivers were not always available to both pilots. Only one might have a particular receiver. To ENTER the P2 seat from the P1 seat we must press CTL + SHIFT + ENTER and to go BACK to the P1 seat we must press CTRL + SHIFT + BACKspace.
There is little point in MDL developers providing multi crew VCs if we only ever occupy one of the provided seats. We should learn to fly complex aeroplanes from both pilot seats. We should of course only ever occupy the left hand (P1) seat of any airliner while using a left handed joystick with right hand throttle. Have you practiced left hand / eye brain co-ordination flying left handed from the left hand seat? Joysticks with configurable throttle placement are not just for left handed sim pilots!
In the vintage phase of aviation history, in most cases, the instrument approach to the destination airfield, or sometimes to the instrument runway, was discontinued upon positive identification of the different landing runway; a visual join of the circuit, at normal circuit height, for the landing pattern of the landing (not instrument) runway then being commenced. The supplied on screen handling notes assume that the landing runway will rarely be the instrument runway in the relevant timeframe and assume discontinuation of the instrument approach to join the relevant and normal visual circuit for the landing runway.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
At this date retractable landing gear still had a very high failure rate. The bay doors could be pumped open and the gear could be pumped up or down by hand when the powered mechanism failed, but that took time. Achieving two greens *before* entering the circuit and *before* commencing the final descent to land during a straight in approach to land was mandatory. These are not modern airliners with low failure rate, or triple redundancy, modern systems. They need to be operated differently.
FLAP - is a CAMBER CHANGING DEVICE
We must reduce profile drag (IAS) to 170 KmIAS before we attempt to extend the GEAR. Once we extend the GEAR the aeroplane will try to decelerate due to the extra drag and if we allow it to decelerate it will pitch up in level flight. We must extend FLAP to increase wing camber to pitch the aeroplane nose down again (in level flight). Flaps are wing camber changing devices not air brakes. They control aircraft pitch not 'speed'. We need them because we reduced profile drag (IAS) to extend the GEAR, not in order to reduce IAS.
We need to see where we are going and so we must (learn to) control aircraft pitch independently from aircraft flight path vector. That is what flaps are for.
We need to reduce our profile drag to 170 KmIAS to extend the GEAR and we need FLAP 2 to maintain our view ahead at only 170 KmIAS. We need more boost (C) to sustain 170 KmIAS with GEAR and FLAP 2 extended else the aeroplane decelerates and pitches up. Neither the need, nor the timing, nor the sequence is random.
We must impose our will on the aeroplane. We pitch it so that we can see where we are going. We pitch it to achieve our head up parallax cues. Pitching it has nothing to do with climb and descent. We simply choose whether to pitch the nose above or below the flight path vector using FLAP. We can easily pitch the aeroplane +2 or -2 without / with flap in level flight and we can pitch it -5 or -1 with / without flap when descending on a -3 degree glidepath just as easily.
We take the aeroplane for a ride on our terms. We never let it take us for a ride on its terms. We achieve our head up parallax targets using flap. We achieve our altitude targets using throttle. We achieve our IAS targets using stick or yoke or elevator trim. Most flight sim enthusiasts fail to teach themselves those three primary skills and consistently make the wrong type of input in pursuit of the wrong kind of operating target. During an approach to land , regardless of current IAS (target), the view ahead is whatever we want it to be, from the real glideslope, all of the time, and we control our view of the terrain with FLAP.
The on screen handling notes tell us what our IAS target is for each phase of the flight which has an IAS target and they tell us the FLAP setting that will allow us to pitch the aeroplane to see and comply with our parallax compliance cues.
PARALLAX COMPLIANCE
On final approach we always have a parallax target. We always need our touchdown point to be at the correct place laterally and vertically inside the parallax 'frame of reference' (the windscreen). In aeroplanes with no parallax gun sight, (or electronic head up display = HUD), we cannot physically overlay an object of reference attached to the aeroplane on the external object of reference (runway touchdown zone). We must however always work out where the parallax sighting cue would appear inside the entire windshield frame and then we must achieve and sustain that 'head up parallax picture' as though we had an electronic HUD, but without that HUD.
We cannot judge where the 'external of object of reference' is vertically within the frame of reference if either the upper or lower bound of the frame of reference is not visible. We must literally 'frame the approach picture' with the windscreen frame and control parallax compliance (mostly with throttle).
The approach must be flown from the default eyepoint placing the portion of the windscreen where the HUD cue would be, if we had one, over the runway. We must (learn to) visualise, recognise and achieve, the HU parallax overlay cues during *every* approach whether or not we have an electronic HUD, whether or not we have approach lighting.
First the developer has to create the physical MDL (VC) frame of reference, (the windscreen), correctly. Then the developer has to code the eyepoint correctly. Then the developer has to code the eyeline correctly to deliver the real parallax (pitch) frame of reference so that the entire windscreen is within our field of view (FOV) as our literal' frame of reference' = non electronic HUD, because that is how it works in real life. Then the developer has to deliver handling notes which explain the operating targets that cause the touchdown point to appear *correctly placed* within that HU 'frame of reference', (not randomly out of sight due to the delivery of randomised eyepoint and eyeline code, or none at all).
Then *we* must (learn to) achieve all the handling note energy state and variable geometry state targets notified by the developer. Then we must use the entire windscreen as our frame of reference = HU display, while learning to position the runway (touchdown point) perfectly inside the 'frame of reference' = HU display flying *Head Up*, constantly adjusting throttle and occasionally adjusting flap to position our target (the touchdown zone) where the electronic HUD cue would be in our 'frame of reference. We cannot (learn to) achieve head up parallax compliance whilst flying head down looking at gauges and ignoring the carefully provided HU parallax cues.
We do *not* pitch the aeroplane with stick or yoke or trim to achieve our parallax cue. That would cause deviation, (climb above or descent below), the compliant (usually minus 3 degree) glidepath. We use stick or trim only to achieve our profile drag (IAS) targets. We use throttle to sustain the compliant glidepath by sustaining our parallax target, already in the compliant variable geometry state, as we reduce to each successive lower IAS target.
Unfortunately many / most aircraft releases deliver none of those things and so flight sim enthusiasts cannot learn the relevant skills. To achieve complaint flight skills we need compliant MDLs, containing compliant VCs, with compliant eyepoints and compliant eyelines as well as handling notes explaining what constitutes energy state and matched variable geometry state compliance.
Once we have an aircraft which offers all of those things we must learn what flaps are for, how to achieve precise IAS targets, and what those targets are, in order to impose (approach) compliance on any aeroplane. We need phase by phase, action by action, handling notes which explain the energy state targets and the associated variable aircraft geometry states required to achieve those operating targets. If we fail to comply with the correct IAS targets, in the correct sequence, in the correct variable geometry state, we lose control of aircraft pitch and at the same time we lose control of our head up parallax compliance. So within the Fiat G.12CR on screen handling notes we see;
****************************
Approach Circuit and Landing:
C => 0.5 until over boundary fence
*Before Glidepath or Circuit*:
C = 0.5
REDUCE = 170 KmIAS
COWLS = 20%
GEAR = DOWN
FLAP = STAGE 1 & 2 (two lights)
C as required to sustain
170 KmIAS
Downwind:
RPM = 2000
170 KmIAS
Base Leg:
C => 0.5 as required to
Turn final @ 155 KmIAS
Final:
CARB HEAT = COLD
In time to achieve Vref
FLAP = STAGE 3 (four lights)
Vref Cross boundary @ 135 KmIAS (all weights)
C < 0.5 allowed
FLARE
********************************
Neither the values, nor the sequence is random. If we fail to comply with and sequence our energy state and variable geometry state targets correctly we also lose control of the parallax picture we must achieve.
Every aeroplane has head up parallax cues. Most are not electronic. Developers must learn how to encode them and explain how to achieve them, and then we must learn how to use them to sustain compliant parallax from the relevant encoded eyepoint.
INSTRUMENT RUNWAY - is rarely the LANDING RUNWAY in the vintage era
In most cases we will *not* be making a straight in approach and we will reach the glidepath of the *landing* runway only at the end of our downwind leg in the circuit pattern for the landing runway, but we must reduce our profile drag to 170 KmIAS before we join that downwind leg and if we make a straight in approach to land on the *instrument* runway we must reduce our profile drag to 170 KmIAS before we reach the glidepath for that runway.
We must achieve successful and confirmed GEAR and FLAP 2 extension before we intercept the glidepath for the runway we intend to land on. The glidepath for the instrument runway has no relevance if it is not the landing runway.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
.......see also tutorials within the Savoia Marchetti S.73 V2 and Fiat G.18V hosted at Avsim and elsewhere.
Either way we never allow IAS to decay below 170 KmIAS until we intercept the glidepath for the *landing* runway.
CONTROLLING APPROACH THRUST
Airscrews do not turn themselves. That requires fuel. Most flight sim enthusiasts consistently fail to supply the necessary fuel during the approach. Having commenced the approach at the wrong IAS, in the wrong variable geometry state, at the wrong altitude, from the wrong location, they close the throttles randomly to slow down randomly. The engine spools down, the airscrews spool down, thrust collapses, and the aeroplane sinks hard. Parallax compliance is lost. The approach is already unstable if not actually out of control.
Every airscrew needs a specific minimum fuel flow to sustain minimum safe approach RPM and minimum safe approach thrust. These values are not random. They are mandatory. They must be learned and then they must be applied. As it happens both the Fiat A.74 and the Bristol Pegasus need at least 0.5C to spool their different screws to their different minimum safe approach RPM to prevent uncommanded high rates of sink.
We demand our target RPM with RPM levers, but those demanded RPM are not achieved by magic. We are responsible for using the throttle(s) to sustain the boost (fuel flow) required to spool the screw to that minimum safe RPM as windmill effect diminishes as we achieve ever reducing planned IAS targets through the approach. A fuel flow which will spool a screw to 2000 RPM with huge windmill effect = profile drag = IAS acting on the screw at 170 KmIAS is not guaranteed to still windmill the screw to approach RPM = 2000 as profile drag on the screw = windmill effect = IAS diminishes to 135 KmIAS.
We must learn and apply the minimum boost required to spool the engines and screws to minimum safe RPM at Vref (the profile drag = IAS we must reduce to as we cross the boundary fence). We must not allow IAS to decay below Vref since, other bad things apart, it will cause engine spool down.
If cleared for a straight in approach to land on the instrument runway we must have GEAR DOWN, and FLAP 2, at 170 KmIAS as we intercept that glidepath, on the extended centreline, at the correct altitude, (shown on the real approach plate); not a random altitude, at random IAS, in a random variable geometry state, with random C and random RPM applied. Everything has an operating target and each operating target has a specific sequence in which it must be achieved. Flight simulation is the hobby of learning what all those targets are and learning to achieve them in sequence, in real time.
Flight simulation is the hobby of learning how to operate a specific aeroplane type in compliance with the rules of the real world in an historically and mathematically accurate virtual environment. It is not a children's game with made up rules. Unlike a children's game the knowledge and skills learned are worth hundreds of thousands of dollars per annum in the real world. Consequently learning them is not trivial, and may take years of part time study, as well as practice, practice, practice.
In the absence of radar vectoring, (absent for most of the Fiat G.12 era), all aeroplanes intercept the real glidepath, at the real altitude, on the real approach plate. The correct altitude is different at each destination. In a particular aeroplane we must always intercept the final glidepath at the same IAS in the same variable geometry state and power state which is correct for that particular aeroplane. The altitude and place varies. We must learn to impose those multiple operating targets on the engines and airframe. During a visual circuit we intercept the final glidepath long before we intercept the final approach course; typically as we turn base leg. In any event we choose where we intercept the glidepath in a visual circuit because we *plan* that interception very carefully so that it is standardised and not randomised.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
With Fiat A.74 engines we sustain 170 KmIAS, with GEAR and FLAP 2, with 2000 RPM, until we reach the G/P for the *landing* runway. This requires more than 0.5C at any weight, in any weather. We allow IAS to reduce below 170 KmIAS only as we intercept the glidepath. Only now do we reduce C to promote further deceleration, but we do not reduce below 0.5C because we must not allow the engines and screws to spool down as we reduce IAS (windmill effect). We control our rate of deceleration carefully by varying C only within prescribed limits. Our next operating target is 155 KmIAS which is the value we must achieve and sustain throughout the turn from base leg to final. This is not a random number either.
Using the wing camber associated with only FLAP 2 it is not safe to allow IAS to fall below 155 KmIAS during a turn. Uncommanded sink would occur. After we are lined up with the runway, and we are sure can keep our wings (almost) level thereafter, we can reduce to Vref = 135 KmIAS, but only as we cross the boundary fence / hedge of our destination airfield. When we should apply FLAP 3 (confirm with 4 lights) depends on current weight and weather and that judgement is a learned skill. It cannot be promulgated in handling notes. The Fiat G.12 is a commuter / utility plane and we do not really need to vary Vref versus weight. If we fuel plan correctly approach weight will hardly vary. However later heavier versions have higher Vref all of the time.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
****************************
Approach Circuit and Landing (G12-CR ):
C => 0.5 until over boundary fence
*Before Glidepath or Circuit*:
C = 0.5
REDUCE = 170 KmIAS
COWLS = 20%
GEAR = DOWN
FLAP = STAGE 1 & 2 (two lights)
C as required to sustain
170 KmIAS
Downwind:
RPM = 2000
170 KmIAS
Base Leg:
C => 0.5 as required to
Turn final @ 155 KmIAS
Final:
CARB HEAT = COLD
In time to achieve Vref
FLAP = STAGE 3 (four lights)
Cross airfield boundary @ 135 KmIAS (all weights)
C < 0.5 allowed
****************************
Without 'realistic' flight dynamics, matching detailed handling notes, and carefully designed VCs we cannot recognise pilot error, (non compliant operation of the aircraft), and we cannot learn how to comply with our energy state, variable geometry state, and power state targets on time, and in the correct sequence. What we see when flying head up must demonstrate whether we are flying proficiently and whether we are achieving our multiple concurrent operating targets. No one can guess what those targets are. They must be provided by the developer within phase by phase and step by step handling notes which we must study and then learn to impose.
On final we must judge when to deploy FLAP 3 to achieve our target of 135 kmIAS as we cross the fence. Only as we cross the boundary fence do we reduce throttle below 0.5C to force the screws and engines to spool down rapidly, promoting rapid deceleration only as we flare to land at less than 135 KmIAS.
.......see 2008 Propliner Tutorial from www.calclassic.com/tutorials
LANDING
We do *not* attempt to make three point landings in taildragging propliners. We land on the mainwheels. We asses our residual drift whilst we are still tail up. The tailwheel is still locked to aircraft heading. We correct residual drift with rudder and only then pull the locked tailwheel gently into contact with the runway to prevent yaw. In taildraggers our view ahead and our situational awareness diminishes significantly after we pull the tailwheel into contact. We steer only with rudder until late in the landing roll.
********************************
After Landing Phase:
FLARE
After mainwheel contact
CORRECT any residual drift
PULL TAILWHEEL GENTLY INTO CONTACT
YOKE FULL AFT
COWLS = FULL OPEN
FLAP = UP
BRAKES = as required
RPM = MAX before taxi
TAILWHEEL UNLOCK before taxi
********************************
We unlock the tailwheel only before we need to taxi clear of the runway. We do *not* use rudder steering to *taxi *complex taildragging propliners within MSFS. The rudder my move, but we are using wheel steering and must make our inputs accordingly and by reference to our head up parallax targets from the relevant eyepoint.
When landing on grass and desert runways it is usually bad practice to apply wheel brakes with FLAP down in low wing aircraft whose flaps extend behind the wheels. The braking action spits stones and other debris into the flaps. Flap damage is even more likely during wheel braking on runways with frozen snow and ice. That is why correctly designed real world STOL aircraft always have high wings. Concrete and tarmac runways are inspected frequently for foreign objects and use of wheel brakes and flap together in low wing aircraft becomes acceptable, but all varieties of Fiat G.12 belong mostly on grass and dirt where those runway types still exist.
Relevant exercises within the tutorials (supplied as above) may be flown using the Fiat G.12 in lieu of the aircraft cited in those extensive tutorials. It is a waste of time flying them in aircraft with random flight dynamics, improperly designed cockpit environments, or without detailed phase by phase and step by step handling notes. If the tutorial exercise explicitly requires an unobscured arc radio compass use the G.12-LB and tune the relevant NDB to ADF2.
The opportunity to procure the valuable real world skills of compliant flight using MSFS as the virtual training environment exists, but acquiring the relevant knowledge and skills takes considerable time and effort. Flight simulation tends to be one of those hobbies where what we achieve by way of satisfaction depends on the effort we each put into achieving carefully targeted step by step goals which incorporate ever higher levels of realism. With no specific goals to achieve flight simulation can be a huge waste of time in which one aeroplane differs from another only in colour and shape and every flight is a series of random events with no sense of personal progress or achievement.
It doesnt have to be like that!
VIRTUAL COCKPITs are REQUIRED to deliver HEAD UP REALISM
This tutorial has constantly referred to 'head up flight' and 'parallax compliance'. They are at the heart of learning to fly real aeroplanes. Yet many flight sim enthusiasts never learn those key skills, even though they may think they have. Many other flight sim enthusiasts find VCs irritating because they never learned how to configure them properly. For reasons explained throughout this tutorial the G.12 release is VC only. Even if you think you understand how to configure a VC I strongly advise you not to skip this final section of the G.12 tutorial.
The parallax relationship between two objects of reference, one in motion and the other fixed, is a function of the *eyepoint* from which they are both viewed. To learn, (or retain), the skill of head up flight our eyepoint must be real so that we see during flight simulation what the real pilot sees, so that we can react identically to the same parallax cues.
Even when we simulate the operation of a real aeroplane using 'realistic' flight dynamics, the view ahead is real, (delivers the real world parallax cues), displaying whether the aeroplane is being operated compliantly or badly, *only* if we operate it from the real eyepoint. Flight simulators exist to deliver those real head up parallax cues to us via;
1) real eyepoint and eyeline.
2) real flight dynamics
3) real VC frames of reference (both windscreen and side window)
4) *appropriate* Field of View (FOV)
The purpose of both 'realistic' flight dynamics and 'realistic' VCs is to quantify and demonstrate pilot error so that we can recognise our errors and alter how we are operating the aircraft to eliminate those pilot errors.
Some developers are able to deliver 1 to 3. Unfortunately (4) is always in the hands of the consumer and most consumers fail to configure their FOV correctly.
Once upon a time, long ago, MSFS was MSDOS software. It could only be used full screen. The only viewing mode was 'Cockpit View' (CV). Some developers wrongly called it 2D panel view. It was horribly limited because it relied on developer creation of a fixed scale and size bitmap of the cockpit interior, that only worked on screens of a particular aspect ratio, created from a false eyepoint that we could not change, looking down a false eyeline that we could not change. Cockpit View displayed a full screen (front) window, overlaying the external environment which was supposed to cover all of the rear full screen window to deliver true perspective.
Many '2D panel' developers did not even grasp that and failed to encode either true perspective or true parallax. Of course it was possible for developers to deliver a 'Cockpit View' that met Microsoft SDK requirements, but most failed because they never tried.
Even when an experienced developer delivered an SDK compliant CV it was fixed screen format, fixed scale, fixed eyepoint, and fixed eyeline *forever*. If the aeroplane was complex enough to have P1 and P2 side by side in the cockpit the fixed CV eyepoint always had to be far aft of the real eyepoint to deliver condition (4).
4) *appropriate* Field of View (FOV)
which of course meant that a CV for such aircraft could not also deliver condition (1)
1) real eyepoint and eyeline.
the consequence of having a fixed eyepoint, far too far aft compared to real life, was that the windscreen of CVs became a slit or 'letter box' through which far too little of the outside world was revealed. The required 'frame of reference' seen from a fake eyepoint down a fake eyeline and therefore 'out of scale' failed to reveal the 'objects of reference' in the external environment.
Using CVs, (fixed out of scale panel bitmaps), objects of reference that would be fully visible through the real frame of reference were instead obscured by aeroplane interior bitmap because the eyepoint was false and too far aft. This was only slightly remedied by delivery of additional 'landing panels' with a more forward, (but often still entirely false), eyepoint which revealed 'randomly more' of the necessary external objects of reference. In order to deliver
1) real default eyepoint and eyeline.
'Landing Views' always failed to deliver;
4) *appropriate* Field of View (FOV)
With a 'landing view' CV the gauges were out of sight. With any other kind of CV it was impossible to fly an instrument approach to low real world minima transitioning to visual because the approach lights (which should have been visible within the windscreen) were obscured by a huge screen hogging interior bitmap whose windscreen was only a slit whose lower frame was far too near the top of the front Microsoft Window revealing only a tiny sliver of the scenery projected on the rear (full screen) Microsoft Window. The approach lights *were present and displayed in the rear window* of the MSDOS era screen just fine, but obscured by the huge oversize front window fixed scale bitmap.
The MSDOS concept of Cockpit View (aka 2D panels) had another huge flaw. If either the uneducated developer, or the uneducated consumer, varied ZOOM from human vision (ZOOM = 1.0) only the rear full screen DOS window containing the scenery responded. The screen hogging 2D fixed scale bitmap in the front window did *not* respond and all the head up parallax cues were instantly broken.
The laws of mathematics are not subject to democratic amendment. It does not matter how many MSFS users thought (still think??) it was 'kewl' to vary FOV with zoom to see more scenery from a CV; that scenery then had false projection, placement, parallax and perspective. Those uneducated consumers always zoomed out, not in, (often to 0.75), thereby also discarding scenery detail and squashing the mesh. Varying ZOOM from 1.0 whilst using CV view was (still is) very childish.
Both software developers and real aircrew desperately wanted a properly designed desk top flight simulator viewing system which did not use two MSDOS full screen windows, one with fixed scale overlaying a second with variable scale. Both software developers and real aircrew desperately wanted a 3D viewing system in which parallax never altered using code incorporated to 'rescale' everything together so that parallax never varied,
a) by user variation of ZOOM
or
b) by user variation of window aspect ratio
That viewing system is called 'VC view'. it is far more complex than most FS users realise and far more than just 3D. It is 'parallax compliant'. We have had that unbroken viewing system in fully working form since the debut of FS8 in mid 2001. More than eight years later many MSFS users behave as though the Microsoft Windows operating system had never been invented and their operating system was still MSDOS. They still use a broken viewing system that only ever existed to match the constraints of MSDOS.
VC view was the biggest breakthrough ever in desk top flight simulation.
CONFIGURING VC VIEW
Unfortunately configuring VC view correctly is not intuitive. It is counter intuitive. Most consumers who have adopted VC view still do not understand how to configure it. Many consumers still do not even realise that *they* are required to configure VC view VC by VC and that developers cannot configure it for them.
In order to learn (or retain) the skills referred to throughout this tutorial we all need to have both the real head up parallax frame of reference, and the external object of reference, and the gauges of reference, all visible together *at the same time*.
The display requirements for flight simulator training or skill retention are;
1) real eyepoint and eyeline.
2) real flight dynamics
3) real VC frames of reference (both windscreen and side window)
4) *appropriate* Field of View (FOV)
In the bad old days of (2D) Cockpit Views before 2001 if we varied FOV we screwed up scenery projection, parallax and perspective. Conversely since 2001 we have been able to vary FOV at will without screwing up those FS variables, but most flight sim enthusiasts still fail to control their FOV to deliver to themselves the necessary 'frames of reference', and the necessary 'gauges of reference'. Many others vary FOV using only ZOOM which causes them to suffer graphics penalties (see later). Most behave as though MSFS is still MSDOS software that is designed to be run full screen.
FOV control by ZOOM alone..... ('works' but is not optimal).
It is possible to use a VC as though it is only MSDOS software still constrained by the limitations of MSDOS, but you will pay an avoidable graphics penalty for that choice. If a VC is used full screen in that way *you* are responsible for creating the *necessary* 'frame of reference' and for creating an *appropriate* FOV which makes the 'gauges of reference' visible by default. Your default FOV (obtained by pressing the space bar) on *your* screen is unknown to developers. In 2009 we have no idea what screen type you use, what 'full screen' aspect ratio is for you, how big it is, or how good your eyesight may be, and so *you* must (learn to) configure the necessary Field of View (FOV) and Level of Detail (LOD) when you first load *any* VC into MSFS.
If you have become habituated to using MSFS as though it is still only MSDOS software designed to be run 'fullscreen' *you* must (learn to) configure VC FOV to match *your* fullscreen aspect ratio using ZOOM alone.
After invoking the supplied VC fullscreen you must vary ZOOM in steps of (about) 0.01 using the SHIFT and - (minus) or SHIFT and + (plus) keys together. You must watch your FOV change on your hardware. You must discover (evaluate) the ZOOM value which delivers the necessary parallax 'frame of reference' AND an *appropriate* FOV which includes the gauges (of reference) which *you* want to be on screen when looking straight ahead (press space bar). The most important requirement is that you ZOOM OUT until enough of the upper frame of the windscreen be visible by default for you to judge exactly where any external object of reference is vertically within that displayed internal frame of reference (non electronic HUD).
You may need an even deeper FOV of course. If the lowest row of gauges is not visible, (when the upper frame of the windscreen is visible), and you do not want to be forever scrolling with a hat switch to reveal them, then *you* are responsible for zooming out in further steps of 0.01 until the 'gauges of reference' are also visible by default (when you press the space bar). The same applies if you deem gauges in a roof panel to be 'gauges of reference'.
You may need a wider FOV instead of course. If the rightmost row of 'gauges of reference', (from the real P1 eyepoint), is not visible, and you do not want to be forever panning with a hat switch to reveal them then, *you* are responsible for zooming out in further steps of 0.01 until the 'gauges of reference' to your virtual right are also visible by default, (when you press the space bar).
X RAY VISION CHEAT MODES
While you are varying ZOOM in VC view take special care to notice that you are *not* altering the parallax of the 'external objects of reference' versus the 'frames of reference'. The 'object of reference' that is bisected by the 'frames of reference' never alters. The mathematics of VC view are complex and prevent us from acquiring x-ray vision. We can create any internal FOV we like, but what we can see from the real eyepoint through the real frame of reference never alters, and is always real.
The whole point about VC mode is that we have total control over cockpit FOV and that in difference to CV mode there is no FOV we can create which will destroy the vital parallax relationships we need to achieve compliant head up flight. Yet developers still see posts in forums claiming that VCs have restricted FOV!
The FOV of any VC is exactly what *you* want it to be, but *you* have to create it. Developers have no idea what screen you have and you must decide how much panning and scrolling to see gauges you want to impose on yourself after taking into account your eyesight and your screen size. *You* must be able to read the gauges of reference on your screen size and that may limit your choice of 'zoom out'. VC view is not only obviously superior to CV view, it is actually as perfect as any desktop simulation viewing system can possibly be.
A larger FOV is not the same thing as a cheat mode to create x-ray vision. It was never any secret why CFS users prefer CV to VC. For competitive combat a cheat mode misnamed ZOOM that actually allows x-ray vision through the metal structure of the aeroplane to reveal more 'objects of reference' is a 'plus' from a childish game playing perspective. But for flight simulation we need to have X RAY VISION cheat modes OFF and that is what VC view delivers. Any internal FOV we like with no x-ray vision and perfect parallax revealed.
SAVE FLIGHT
Most flight sim enthusiasts have also not understood what they are required to do next.
Having created the perfect FOV for our screen, and our eyesight, for that particular VC, with its particular frames of reference and gauge layout, we are required to use the flights/save flight menu to create a .FLT file which saves our individual choice of perfect FOV. So after we take twenty seconds *just once* to deliver to ourselves the 'frames of reference', and 'gauges of reference' in the Fiat G.12-CR we are required to use 'save as' to create a file called 'perfect G.12CR FOV.FLT' which in future we must use to load our perfect G.12CR FOV. We must change location and weather only after using that 'G.12CR start up flight' file to load the FS values which are correct for our hardware and our eyesight during use of *that* VC.
Because different varieties of G.12 have different gauges and gauge positions, both in real life and in MSFS, each may require a different ZOOM to render the 'gauges of reference' visible by default. Each may need its own 'start up flight' file. The FOV we require is a function of real windscreen size and real gauge placement replicated within a given VC.
If you have never learned how to use freeware such as 'FSMETAR' to load the stored weather of your choice, (after loading an aeroplane using the correct FOV), you should learn to do so.
FOV control by ASPECT RATIO alone........ (also 'works' but is not optimal)
Since the debut of FS8 in 2001, MSFS has been designed to run inside an *MSwindow* whose carefully controlled dimensions deliver the required FOV at optimum LOD.
Before 2001 it was the job of FS developers to deliver that internal FOV and defined LOD as a fixed scale 2D bitmap, but since 2001 it has been *our* job to deliver those things to ourselves by configuring a *window* with the *appropriate* FOV from the real eyepoint, not a fake eyepoint.
Since 2001 it has been the developer's job to encode *only* the real eyepoint and a 'default' eyeline. VC view gave us all the choice of running MSFS *at any ZOOM* without distortion of parallax. We now inhabit a world of carefully configured MS Windows software and *you* must take responsibility for configuring your VC window to deliver the necessary FOV and *LOD*.
Flight sim enthusiasts will never understand how to configure VC view correctly unless they take the time to watch what happens when they create a window with ZOOM < 1 (*use 0.75 during testing) and *hold that ZOOM constant* whilst varying the aspect ratio of their Microsoft VC Window with their mouse.
Watch what happens to lateral FOV as you move only the right frame of the MS Window right and left.
Most flight sim enthusiasts believe that a wider window will provide a wider FOV. They are exactly WRONG. The wider the window (aspect ratio) the more FOV is reduced. If you do not bother to test by dragging the side of the window wider while watching FOV being destroyed as you widen the window in real time with your mouse you will continue to configure VCs incorrectly.
FULLSCREEN DESTROYS FOV!
The worst possible choice of window for VC view using any hardware is therefore fullscreen!
The wider the window you run a VC within, the worse your FOV. The 'thinner' you make the window the more cockpit interior (gauges) you reveal *in all directions*. The more gauges you reveal by creating a narrow window the smaller each becomes and the harder it is to read.
Remember whether you *reduce* ZOOM to increase FOV, or you *reduce* ASPECT RATIO to increase FOV, you are seeing exactly what the real pilot sees through any cockpit window and you see it with true parallax at any ZOOM and any ASPECT RATIO. For flight simulation software to work correctly the viewing mode must *prevent* any change of *scenery FOV* as ZOOM alters. We must be allowed (forced) to see each external 'object of reference' positioned inside the interior 'frame of reference' with exactly the parallax cue the real pilot sees, at any ZOOM, and at any MS window ASPECT RATIO.
The code used to achieve this is not simple zooming of everything in the Microsoft VC Window. In FSX Microsoft made this more obvious by calling what we see a 'camera view'. As we extend or retract the zoom lens we see more or less interior, but ZOOM is not the same thing as X-ray vision. Even in FS8 and FS9 the code is 'camera' code. That code is doing complex things which make VC mode work differently to how most FS consumers think it works.
CV viewing mode was always comprehensively broken. We could have nothing better when we had only MSDOS as an operating system. It is a huge error to go on using the MSDOS method of flight simulation more than eight years after it was superseded by a flight simulation viewing system, that actually works.
We have now discovered what most MSFS users never grasp.
If we stretch the MS window sideways we lose (not gain) FOV. To restore visibility of the necessary 'frames of reference' and 'gauges of reference' we must reduce ZOOM (zoom out) as we increase aspect ratio.
ZOOM = 1 is OPTIMAL.
Ideally we would like to use ZOOM = 1 even in VC view. If we reduce to ZOOM = 0.707 each object in the external scenery is drawn using only half as many pixels (0.707 x 0.707 = 0.5). Using ZOOM = 0.707 halves our level of detail (compared to the intention of the scenery designer). It makes each object in the external scenery almost 30% 'shorter' or 'flatter' or 'lower' than it should be. *That includes all of our mesh*. Applying ZOOM = 0.7 (alone) to control FOV squashes all our mesh by 30% compared to reality.
Even if you do not care at all about functional realism it is unlikely that you really want to run MSFS with half the intended level of scenery detail and badly squashed mesh. Yet that is what most flight sim enthusiasts do.
OPTIMAL GRAPHICS.
Optimal FOV and optimal ZOOM are incompatible. Yet they are both configurable. The optimal way to run MSFS is in VC viewing mode in a window which is not fullscreen. Configuring each VC before we save the necessary FOV in a .FLT is not a question of varying only ZOOM, or of varying only WINDOW ASPECT RATIO. The optimum graphics mix requires ZOOM below 1.0, yet as close to 1.0 as possible to maximise LOD, and to squash mesh as little as possible. That requires a window that is not fullscreen (not even on an 8:6 screen).
*You* are responsible for configuring both ZOOM and WINDOW ASPECT RATIO before you create your personal start up flight for each new and existing VC, (not just new Fiat G.12 VCs). Full screen is never the correct choice. Learn to constrain the VC MS window to a window less than fullscreen, using the product .cfg file (e.g. FS9.cfg).
Having spawned MSFS in that less than fullscreen window (to allow ZOOM to be higher than it can be at fullscreen) we must adjust zoom for each new VC inside that default VC window size, and then save the necessary .FLT file for future use in that invariant VC window which is used with all VCs.
Test for yourself that you can use ZOOM = 1 with more than adequate FOV in all directions, but that to do so the window must be very narrow. That is not optimal. Using aspect ratio alone to control FOV is wrong, just as using ZOOM alone to control FOV is wrong. We must learn how to use both aspect ratio and zoom together to create the optimum FOV on our hardware viewed with our eyesight.
DEFAULT FOV IN THIS PRODUCT
The *eyepoints* in this product are real. This product has been released with 'default' *eyelines* that deliver the required FOV from the real eyepoints in a window that is 8:6 ASPECT RATIO at ZOOM = 0.75
Inside the 'common folder' we have provided jpgs illustrating the minimum default FOV that *you* need to create for the short fuselage, and long fuselage G.12s, before saving your personal G12_shortFOV.FLT files and G.12_longFOV.FLT files (call them whatever you like). They show the default FOV at 8:6 ASPECT RATIO at ZOOM = 0.75 and illustrate the minimum FOV required to provide you with the necessary default 'frames of reference' and the appropriate view of the default 'gauges of reference'. You must use the procedures above to replicate that minimum FOV on your hardware at your chosen ZOOM.
You 'may' wish to create a larger FOV with worse LOD and even more flattened mesh. After you have created and saved your default FOVs, during subsequent FS sessions, you can invoke those saved default FOVs at any time by pressing the keyboard space bar.
Most flight sim enthusiasts fail to create and impose the necessary default FOV when they first procure a new VC, fail to save the necessary FOV for future use, and have a miserable time panning and scrolling to see what they should be able to see without needing to pan or scroll forever after. Using MSFS with a poorly configured FOV is just a lazy consumer choice. Thanks to MSWindows flight simulation does not have to be like that.
MS WINDOWS - not MSDOS
Just like any other MS Windows product MSFS is designed to display more than one window at the same time on a single screen. We undock the other smaller windows so that they do not overlay and obscure the large (but not fullscreen) VC window. The screen space no longer occupied by the VC window contains the GPS, the radio stack, the handling notes, the approach plate, or whatever we may need alongside the VC at the moment. Those undocked windows are 'corner dragged' to fit the spare screen space.
Remember a wider VC window destroys FOV and to prevent that we must instead destroy LOD with ZOOM < 1 to restore FOV. In computer graphics bigger is not always better. There is always an optimum VC window aspect ratio that is never full screen. The wider the screen aspect ratio the less the optimum VC window approximates fullscreen. Developers cannot deliver the correct mix for your screen aspect ratio, your screen size, and your eyesight. We must all learn to configure VCs, using the optimum window shape versus the optimum ZOOM for that shape, to deliver the optimum mix of FOV and LOD on our own hardware.
We want the biggest VC window that will allow *appropriate* FOV at our chosen ZOOM < 1 (chosen loss of LOD).
Long ago at the start of the second paragraph of this tutorial, just after I warned those not interested in flight simulation realism to stop reading I explained;
Flight simulation = compliant operation of aircraft within a mathematically realistic virtual environment; is only achieved when we are able to deploy substantial acquired knowledge and skill to extract the realism embedded within the product.
I concluded that second paragraph;
If we take it one step at a time, both the knowledge and the skills needed to achieve compliant operation of a real aeroplane, using real historical, (but still current), procedures within a mathematically realistic virtual training environment will gradually fall into place. Flight simulation is nothing less.
Hopefully this tutorial will allow readers who make that effort, step by step, to achieve Flight Simulation, as well as a much better understanding of the Fiat G.12 family, and maybe some wider aspects of aviation in general. Most of you will need to consult and use the other cited tutorials as well.
