Question

Which of the following is correct?

(a) Rubber engine can be stretched during A/C sizing

(b) Rubber engine is fixed during sizing

(c) Lift is always same as engine thrust

(d) Engine sizing will be same for every A/C in the world

I had been asked this question in a job interview.

This question is from Rubber-Engine Sizing topic in division Initial Sizing of Aircraft Design

Answer 1

Right answer is (a) Rubber engine can be stretched during A/C sizing

The best explanation: A new engine used during sizing is flexible in terms of size, thrust etc. Such an engine is called rubber engine. They can be stretched during sizing as per requirements. Lift will not be same as thrust. Engine sizing will be different for different requirements of aircraft.