The parameters are: MTOW, MLW, MZFW, OEW, maximum fuel weight, fuel flow rate and true airspeed. Measured in lbs and kts. Not given drag so unsure how to apply Breguet equation. Trying to construct a payload range diagram!

  • 1
    $\begingroup$ If you combine the amount of kg fuel used per seconds with total fuel available you can calculate the total possible flying time. If you know how long you're flying at a certain velocity, you can calculate the distance traveled. $\endgroup$
    – ROIMaison
    Oct 30, 2015 at 14:03
  • $\begingroup$ In addition of @ROIMaison remark, assuming you don't have the fuel flow rate, you cannot calculate the range without the L/D ratio. It would be like trying to find the range of a car without knowing the slope angle of the road. $\endgroup$
    – mins
    Oct 30, 2015 at 14:15
  • $\begingroup$ Got it, thanks people! $\endgroup$
    – Steino12
    Oct 30, 2015 at 14:24

1 Answer 1


If the fuel flow rate and the true airspeed are for the same polar point, the answer is easy. You cannot, however, determine if this is your maximum range because you do not know any other points of the polar.

Your fuel consumption is MTOW - MLW. The flow rate will give you the flight time when you divide the fuel by the flow rate. With the flight time you can calculate the range by multiplying it with the airspeed. Hint: Convert all data into metric first so you don't screw up the calculation.

The maximum range can be done the same way using MTOW - MZFW for the fuel mass. MZFW - OEW will tell you how much payload remains at this point. The only impossible part is the transfer range point - use the maximum range and assume that the aircraft will fly as far with a lower take-off mass as with MTOW.

The Breguet equation will not work in this case.


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