Contents:
1. Installation
2. Motivation
3. Using the fuel calculator
4. Expanding the database
5. Determining fuel consumption characteristics
6. Limitations
7. Credits
8. Copyright/Disclaimer
1. Installation
Just copy Fuel.xls into any directory of you harddisk and start it with MSExcel.
2. Motivation
Almost all fuel calculators I have seen so far are either for a specific aircraft only; or they require a lot of data input. I like the general idea of Roy Hahmann's fuel calculator but it requires 8 input fields and 13 adjustments. So my idea was to store most of the data in a database.
In fact I expanded the calculator by two databases - one for aircraft and one for airports. This reduces the number of input fields to 5 and only 1 adjustment remains.
3. Using the fuel calculator
First of all click on the 'Fuel Calculator' tab of Excel.
As mentioned in the paragraph before, only five input fields remain:
- aircraft
- start airport
- destination airport
- distance
- time of departure
The first three fields are codes for data lookup in the databases. They must enter valid data as contained in column A of the relevant database (be careful, my sample database is not complete!). If the code exists in the database, a comprehensive text is displayed in the field to the right of the input field; if not '#NV' is displayed. You should then verify your input. As for the sample database, check for zero (0) values in any of the database dependent fields - this indicates that you have most likely picked an incomplete entry in the database. For more details about database values, please refer to the database paragraph.
The distance is important to calculate flight time and thus the required fuel quantity. So far I use 'NAV 30' by Ted Wright for this purpose. If anyone has a good idea how to determine the distance between two airports - just send me a short email and I may include it as a new feature, but I will NOT include a flight planner.
The time of departure is only used to calculate the estimated time of arrival.
If you like you may adjust the flight level for flying to an alternate airport.
Notes:
1- Be careful when using the beginning of descent distance to determine your descend! You should start your descent at the latest at the stated distance from the start of your final approach NOT at that distance from the destination airport!
2- Although I am using the basic coloring scheme of Roy Hahmann's 'fuelcalculator2000', I have NOT decompiled or cracked his code. A careful comparison reveals that some calculations are in fact deliberately different! (E.g.: Fuel is calculated as 6.6 lbs/GAL as in most *.air files; only one average climb rate is used) I have not write protected this tool as I think the work is not very sophisticated and should therefore be available to anyone. On the other hand this enables YOU to edit everything including the formulas! So be careful!
4. Editing and expanding the database
Both the airport and the aircraft database have the same structure: lines are entries and columns are data fields.
You may use the Excel 'Data/Sort' menu to resort your database to your requirements. But you should not use a column with empty data fields as primery sorting criterion. This applies both to the airport and aircraft database. Expanding the database is very simple: just insert a new line (Edit/Insert Line) at any location before the 'end of database' line and fill that line with the necessary data.
As the airport database is simpler than the aircrft database I will explain it first.
The airport database consists of columns A to F of the tab 'Airports'. These fields should be filled with data when using this airport as start or destination airport. Any other colomns are for additional information but are not used for the fuel calculator. The columns A to D are fairly self-explaining and mostly already filled with data (except for some 'holes').
Column E is the average time for taxiing between runway and parking position. I have included values for the airports I know. There are basically two aspects to consider: a) the distance between the runway and the parking position and b) the volume of ground traffic on the airport. (Hey, on a large congested hub you may spend as long as 30 minutes waiting for your departure!)
Column F is the time for flying to an alternate airport. Column G may be used to indicate which alternate airport is referenced.
As already explained in paragraph 3, I use the code in column A for data lookup. I have used the 3 letter code used for ticketing to identify the airports. (i.e. FRA instead of EDDF for Frankfurt/Main) You may use any other coding scheme provided that the same code is only used once!
The aircraft database is somehow more complex and in fact only contains 3 complete entries so far: 'A320-232', 'A330' and 'A340'. All the other aircraft contain Airbus/Boeing manufacturer data only. The main problem is that each aircraft with a different *.air file may have different characteristics. The following paragraph describes which values are important - just fill the database with the values of your favorite aircaft(s)!
The aircraft database consists of columns A to Q of the tab 'Aircraft'. These fields should be filled with data when using this aircraft to calculate its fuel consumtion for a specific trip. Any other colomns are for additional information but are not used for the fuel calculator. The columns A and B are fairly self-explaining.
Columns C to F are for fuel consumption data at two specific cruise levels.
Columns G to I and J to L are for the climb and descend characteristic of the aircraft. As for most heavy jet aircraft in FS98 I have entered 1800 ft/min for climb/descend rate.
Columns M and N are the recommended cruise level and speed of the aircaft. They are colored in green because you may want to modify these values for your specific flight.
Column O is the ground consumption of the aircraft.
Column P is the fuel capacity of the aircraft. It can be retrieved from the 'Aircraft/Aircraft Settings/Fuel' menu of FS98. (I hope this translation fits to an english FS98)
Finally, column Q is the additional reserve fuel for the aircraft as 5% of the total fuel capacity. This value seems adequate for short to medium range airliners but it seens far too much for long range aircraft!
In order to determine the values for columns C through L and O, test flights with the aircraft are recommended since flight dynamics vary significantly. See next paragraph for details on how to determine the relevant data.
5. Determining fuel consumption characteristics
I have determined the fuel comsumption data by doing test flights. (Remember to trun off wind before doing a test flight!) This means I fly one hour at FL390 at nominal cruising speed and check the fuel quantity before and after the flight, then I enter the two values FL390 and the fuel consumption in columns C and D. Then I repeat the same procedure for a lower flight level, one descend from max FL to sea level, one climb from sea level to max. FL and ground consumption.
Notes:
1- For climb and descend you will normally need less than one hour; thus devide the consumed fuel by the flying time and multiply this value by 60 to get the necessary consumption per hour.
2- For ground consumption you should use taxiways and turnings rather than runways since this influences the required thrust.
3- If you find data with the wrong unit, just use the 'Converter' tab of this fuel calculator.
4- Don't be too lazy with the characteristics of your aircraft! A comparison of my test aircraft A330 and A340 reveals that even though the two aircraft are by the same designer and share a common design by Airbus Industries, their characteristics are different!
6. Limitations
The databases contain only samples for testing so far. Everyone is most welcome to provide additional entries for these databases. Send updates to IUP and I may publish an updated version with more data in it. Please keep in mind to state the source of the data you add to the database! (I.e. filename of the aircraft)
As already mentioned, I would like to add a feature to calculate the distance between airports. Anyone who has a suggestion - please send me an email.
7. Credits
My thanks go to Roy Hahmann for the basic idea for a flexible fuel calculator.
Credits also go to Georges Lorsche for his final approach program (shareware) and the huge database. Most elevation data of airports was extracted from his database.
Many thanks to Camil Valiquette for the best A330, A340 and B777 aircraft. They are fantastic both visually and the dynamics as well!
For the best Airbus panels many thanks to Roy Chaffin and Tony D'Ambrosio for the wonderful RealCRT gauges (shareware).
Thank you also to Ted Wright for the flight planning feature of his 'NAV 30' Nav-aid viewer. I also retrieved some additional elevation data with this tool.
Finally I would like to thank all the freeware producers of scenery, aircraft and tools for FSxx - keep going!
8. Copyright/Disclaimer
This package may not be sold or otherwise distributed as shareware or payware. However, you are mostly welcome to distribute it further as freeware!
Although this is an Excel file without macros and should therefor be harmless, I do not accept any responsability for problems arising from the use of this file.
