Chti, thank you.
The lift versus drag curves so that you can see the evolution of the lift to drag ratio for V2 (if you are not limited by 1.1 VMC at 61000lbs) V2+10 V2+20). I guess at V2 the lift coefficient would be CLmax/1.44
I have no idea what the L/D ratio is but I do have the GIII AFM. Can it be determined from this operational data?
Remember that I'm concerned only with one airspeed, 164 KCAS. This may be V2+10 or V2+20 or V2+whatever depending on weight, but it's always 164.
Check the engine thrust for these 3 speeds (lets say ISA - SL)
I've allowed myself the assumption that thrust decay vs. airspeed vs. some amount of ram recovery means I can estimate using initial "stub-thrust" values. I understand that's not 100% correct, but probably close enough. Even if I don't get the absolute values correct, it's only the proportional reference altitude differences at different weights that I'm after. And yes, ISA - SL is the benchmark I want to use.
Getting back to your matters, at what distance from the end of the runway (and from the 35ft clearance) is the mic that measures the sound ? Is it far enough to clear the 2nd segment ? How is the noise measured, it's a matter of time and peak, or only of sound peak?
The mic is at 6500 metres from brake release. At that point the airplane is in second segment climb, flaps 10, gear up, and a thrust cutback from EPR 2.51 to 1.86 has been made. You're quite right, for certification purposes it's time and peak (EPNdB), but I only care about single value peak (in dBA).
Meilleures salutations,
Tom