Question

At what airspeed does maximum gradient of climb occurs?

(a) 1

(b) 2

(c) 3

(d) 4

I got this question during an interview.

My question is taken from Climb and Descent Performance with Thrust-Producing Engines topic in portion Climb and Descent Performance of Aircraft Performance

Answer 1

Correct choice is (a) 1

To elaborate: The maximum gradient of climb occurs at airspeed (u) =1. There occurs negative values for sinγ2  of τ and u when the flight is descending. The climb gradient equation is given by the equation τ-\(\frac{1}{2}\)[u^2+u^-2]=Emaxsinγ2.