Question

What is endurance function?

(a) \(\big[\frac{E_{max}}{C}\big]\)

(b) lnω

(c) \(\big\{\frac{2u^2}{u^4+1}\big\}\)

(d) \(\big\{\frac{2u^2}{u^4+1}\big\}\)lnω

I got this question during an online interview.

The origin of the question is Cruise Method 1 topic in portion Cruising Performance of Aircraft Performance

Answer 1

Correct answer is (d) \(\big\{\frac{2u^2}{u^4+1}\big\}\)lnω

Best explanation: The endurance factor is given by \(\big\{\frac{2u^2}{u^4+1}\big\}\)lnω where Emax is endurance and C is specific fuel consumption. The endurance equation is given by E=\(\big[\frac{E_{max}}{C}\big]\big\{\frac{2u^2}{u^4+1}\big\}\)lnω where V is true airspeed, C is specific fuel consumption, L is lift, D is drag, Emax is endurance, u is relative airspeed and ω is fuel ratio.