Optimum altitude
 

Hi all,

I'm wondering if it's possible to calculate an aircraft's optimum altitude using these four things:
1. zero fuel weight.
2. amount of fuel on board.
3. fuel flow (kg/min) at a specific height.
4. normal cruise speed in mach or kts at a specific height.

Can somebody tell me whether this is possible or not? And if it is possible, how?

Thanks very much,

FutureFlyer

Have a look at the specific air range charts for the aircraft, optimum altitude is the weight/altitude combination for a given speed where you get the greatest distance for a given amount of fuel.

Mutt.

Hi Mutt,

Thanks for your reply. I'll try to make a table with the optimum altitudes for some aircraft depending on the weight (by using speed/fuel flow)...

Regards,

FutureFlyer

Don't forget the climb rate of the aircraft. :D

For Boeing a/c look in the early pages of the QRH. There is a table of Optimum Alt v. gross weight.

If your looking to file a level for ATC; take the ATOW, subtract the Climb fuel, which in light/medium cases, is 1500kgs and this will give you TOC weight and thus the initial filed ATC FL. You can then also assess when the step climb will be by deducting the fuel burn/time for a 2000' or 4000' step climb.

DUCKMAN052001

What has Climb Rate got to do with Optimum Altitude?

Mutt

Don't be forgetting ISA either as on the day this can effect optimum altitude.