Question

Determine the acceleration of an aircraft which is in ground roll segment. Consider weight of the aircraft as 150kN, thrust as 110kN and drag as 10kN. Assume weight on the wheels as 60kN and rolling friction as 0.05.

(a) 5.68 m/s^2

(b) 100kN

(c) 100 m

(d) 3.5689 Kg*m/s

This question was addressed to me during an internship interview.

My query is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design

Answer 1

Right choice is (a) 5.68 m/s^2

Explanation: Given, weight W=150KN, thrust T=100KN, drag D = 10KN, rolling friction f= 0.05, weight on wheels w = 60KN.

Acceleration a = g*(T- D – f*w)/W

= 9.81(100 -10-0.05*60)/150

= 9.81*87/150 = 5.68 m/s^2.