Simviation Forums

Hi There,
I know that aircraft have maximum weights, and cannot land with excessive fuel on board. what is the basic procedures to do fuel planning? Let's use an example:

Aircraft: Default Boeing 737
Distance from departure to arrival: 687.7nm
Flight level: FL330
Estimated Time en route: 1:26
Max Fuel available: 35596.64 pounds
Estimated fuel burn from Flight planner: 9401.6 pounds

are the estimated fuel burn accurate, or not? an what about getting diverted to another airport, etc?

Hi There,
I know that aircraft have maximum weights, and cannot land with excessive fuel on board. what is the basic procedures to do fuel planning? Let's use an example:

Aircraft: Default Boeing 737
Distance from departure to arrival: 687.7nm
Flight level: FL330
Estimated Time en route: 1:26
Max Fuel available: 35596.64 pounds
Estimated fuel burn from Flight planner: 9401.6 pounds

are the estimated fuel burn accurate, or not? an what about getting diverted to another airport, etc?

Well, I don't know what a 737 burns...  but in the real world, these are the rules... (in Canada at least)

VFR: fuel to get to your destination + 30 min. reserve
IFR:  fuel to get to your destination, fly an approach and missed approach, go to your alternate, fly an approach and missed approach, + 45 min. reserve.

Well I wouldn't trust what FS reports for fuel burn.  If that is a 737-400 your talking about (FS9), I would suspect that the fuel burn reported is really shy of how much it would take, at that Flight Level, to get to your destination. 

I'm no flight dispatcher, but I would assume that a large number of factors come to play: wind, distance, weight on aircraft, and of course, the rules.  Check out some of these resources, as they might be helpful:

-http://www.b737.org.uk/pilotnotes.htm (check out the rule of thumb too)
-http://hsors.pagesperso-orange.fr/acftdata.html

I pulled a dispatch sheet once from an airline I used to work for, and I believe that airliners carry just barely enough to reach their destinations with a little extra for diversions and weather.  On a 430 nm route, at FL400, on a 737-700, the plane only arrived with just 2 or 3 thousand lbs of fuel (if even that) if my memory serves me right.  I believe real world dispatchers factor a lot of the variables in via computer software (which probably varies from operator to operator).  I've shadowed an airline dispatcher once, and that was the impression I got. 

In the sim, myself, I just prefer using pre-made fuel calculators, which are usually available for free.  With addons that come with flight management computers, I often just see how much fuel it takes me to get to my destination, and trim or add fuel as needed. 

Of course, with lighter aircraft, fuel may not be such a restrictive factor.  Airliners, definitely. 

A real flight dispatcher would probably be more helpful than this. 

When I plan my fuel, I just put what the nav log says +15% of the total amount the aircraft can take. It's not failed me yet!

I believe real world dispatchers factor a lot of the variables in via computer software (which probably varies from operator to operator).

You're about there. Real world operators use internet based software such as Jeppesen JetPlan. Essentially you enter your flight plan route, and can enter a variety of parameters for cruise altitudes, aircraft configuration, weights, cruise mach/speed etc, and diversion airfield. This all goes to a big server somewhere, it combined with real time and historic data held on the system, to produce and accurate guess as to the fuel required, time en-route etc.

Clever stuff, but surprisingly accurate.

http://www.jeppesen.com/industry-solutions/aviation/business/jetplan.jsp