Question

If my aircraft is in steady level flight and has thrust of 100 unit then, what will be the approximate value of time Easter if change of aircraft weight. Consider SFC as C unit.

(a) -100C

(b) 1000

(c) 1.25

(d) 5.43

This question was posed to me in an interview for job.

My question is from Flight Mechanics in section Performance and Flight Mechanics of Aircraft Design

Answer 1

Right option is (a) -100C

Easiest explanation: Given, thrust T = 100 unit and SFC = C unit.

Now, time rate of change of aircraft weight = -C*T = -100*C = -100C.