Question

What is the basic assumption taken in formulating equations of motion?

(a) All the engines will operate at equal gross thrust

(b) All the engines do not operate at equal gross thrust

(c) All the engines will operate at equal gross drag

(d) All the engines do not operate at equal gross drag

The question was posed to me in quiz.

I'd like to ask this question from Equations of Motion for Performance in division Aircraft Force Systems and the Equations of Motion of Aircraft Performance

Answer 1

Right choice is (a) All the engines will operate at equal gross thrust

For explanation I would say: The basic assumption taken in formulating equations of motion is all the engines will operate at equal gross thrust. There are other assumptions also taken in the case of convectional aircraft there are:

Rate of change of mass is neglected

Aircraft is in symmetric flight

Gross thrust acts in aircraft body axis

Total net thrust is T cosα-DM

Thrust component is small compared to lift component.