Written by Laurent Crenier using Microsoft Visual C++ and the FS98 panel Software Development Kit.
Special thanks to Eric Ernst for his encouragements and Michael Ebner and Peter Koller for their useful remarks.
1. INTRODUCTION
This gauge for Microsoft Flight Simulator 98 is the first attempt to simulate the complex autobrake
system of a big jet. When armed, it operates in conjunction with the automated flight equipment to
pilot the landing gear primary brake pressurization system to generate predictable deceleration
during a Rejected Takeoff (RTO) or during landing. The rate of deceleration can be preset by a cockpit
selector, which is the "visible part" of the gauge.
Though currently this gauge is mainly designed from the Boeing 747-400 system, it works fine with all
type of FS98 jets. If you know precise technical characteristics of real autobrake system(s), please
contact me !
To use the autobrake system in your own panels, you have to copy Autobrake_V2.GAU (with or without Abrakedis_V2.GAU)
in your FS98\GAUGES directory and modify your panel.cfg files as explained in the FS98 Panel Software Development Kit
(downloadable on the Microsoft FS98 site). See the DISCLAIMER section for the gauge utilization license.
That's all !
3. INSTRUCTIONS FOR USE
To use the gauge, simply move the autobrake selector with left mouse clicks. According to the mouse cursor position,
the selector turns clockwise or anticlockwise. If the readout gauge is installed (Abrakedis_V2) , the autobrake status
appears in blue. During the automatic braking, the readout changes to red.
The selector positions are (clockwise) :
RTO ........... If selected, provide maximum braking pressure automatically if the throttles are moved to idle after
reached 85 knots during takeoff roll (It is the Rejected Takeoff situation). RTO selection is not
permitted in flight.
OFF ........... Nothing happens ! Autobrake system is OFF. If you switch to OFF when autobrake is active, braking stops
immediately.
DISARM ........ The selector goes automatically to this position when the autobrake system disarms itself. When selected
manually, is similar to OFF.
Level 1 to 4 .. Provides increasing deceleration rate during a normal landing (see Technical Data). Levels 1 & 2 are
usually selected for landings on dry runways and levels 3 & 4 for landings on wet runways.
MAX AUTO ...... Provides maximal braking pressure during the rollout, e.g. for an landing on a short runway.
4. AUTOBRAKE LOGIC
The autobrake computer which pilots the system is active when the selector is on any position except OFF and DISARM.
It detects automatically the ground, takeoff and landing phases of the flight. The autobrake actions are determined
accordingly. The TAKEOFF phase begins when 85 knots are reached on the runway and ends when the plane leaves the ground.
The LANDING phase begins at touchdown and ends when the ground speed is inferior to 10 knots.
The autobrake system will automatically apply maximal brake pressure during the TAKEOFF phase (that is when speed is
greater than 85 knots) if RTO is selected AND throttles are moved to IDLE (Rejected Takeoff situation).
The system will automatically disarm when the target ground speed is reached (<10 knots) OR if throttles are moved
forward. Manual braking don't disarm autobrake during RTO automatic braking.
The autobrake system will automatically apply appropriate brake pressure during the LANDING phase if levels 1 to 4 or
MAX AUTO are selected (see Technical data). The system will automatically disarms when the target ground speed is
reached (<10 knots) OR if throttles are moved forward (Go/Around situation) OR in case of manual braking. Nevertheless,
manual braking don't disarm autobrake during MAX AUTO automatic braking.
The autobrake system will also automatically disarm in the following situations :
a. On the ground, during the TAKEOFF phase, when RTO is selected and brakes are applied manually.
b. During normal takeoff with RTO selected, autobrake switches to OFF just after the liftoff.
c. If throttles are advanced beyond idle after touchdown, with levels 1 to 4 or MAX AUTO selected (Go/Around situation).
d. When the target speed (<10 knots) is reached by the automatic braking.
5. TECHNICAL DATA
This gauge has been tested during "standardized" landings (ILS approach), with the FS98 Boeing 737-400 at the Brussels
International Airport (EBBR) on the runway 25L, without winds.
You find here the length (in seconds) to decelerate from touchdown to less than 10 knots (the moment when the autobrake
switches to disarm) with each autobrake status. Speed at touchdown was 140 knots, the spoilers were not extended and the
thrust reversers not used.
Autobrake Status Time to disarm
______________________________________________________
During automatic braking, the red "BRAKES" indicator of the Flight Simulator sometimes flickers, especially when
levels 1 to 3 are selected. It's normal !
The reason is that it is currently impossible (due to the gauge development interface) to force the brakes to apply
a constant, non maximal pressure. However, the autobrake computer bypass this "software" problem and applies short,
discontinuous raisings in brake pressure to reach the selected deceleration pattern. This can be seen as an antiskid
simulation !
6. NEW FEATURES IN VERSION 2.0
a. Some bugs of the version 1.0 have been corrected.
b. The gauge is now "transparent". It means that the background color of the gauge is the background color of
your panel (no need to edit the bitmaps with GAUBMP) .
c. The visual appearance is greatly improved when the panel is nightlighted.
d. Manual braking on the ground don't disarm autobrake any more. RTO can thus be selected before taxiing.
e. If RTO is selected, the autobrake switches automatically to OFF instead of DISARM at liftoff.
f. The Go/Around automatic disarm is less "sensitive". You can now push the throttles a bit forward without
disarm autobrake during rollout (to approximately 40% N1).
g. A more detailed documentation is provided (This file !).
7. DISCLAIMER
This gauge is freeware and is provided 'as is'. It will not harm your computer in any way and I will not be held
responsible even if you think that it has.
You may include this file in your own panels and in any panels that you release as freeware provided I am credited
as the author of this gauge and that you include the following condition on shareware and payware use of the gauge.
Shareware and Payware panel designers who wish to use this gauge should contact me by email at :
Laurent.Crenier@village.uunet.be
The B777 panel v3.01 files (B777AB.EICAS.GAU, B777sc_main.BMP and panel.cfg) included in this ZIP file are modified
versions of the original files by Stefano Caporelli, s.caporelli@fastnet.it and Eric Ernst, kordos@erols.com.
8. HOW TO CONTACT THE AUTOR
If you have any comments or suggestions about this gauge, if you know precise technical characteristics of real
autobrake system(s), or if you simply enjoy with it, please contact me be email at :
Laurent.Crenier@village.uunet.be
