Question

An aircraft is flying at cruise level with a velocity of 110m/s at an altitude of 10 km and the dynamic pressure is 5.43kN/m^2. Now assume the aircraft is flying is at sea level with a speed of 65m/s and the same dynamic pressure. In the above data, the velocity 65m/s refers to __________

(a) true air speed

(b) equivalent airspeed

(c) free stream velocity

(d) cruising speed

I had been asked this question in an online interview.

Query is from Pitot Tube in portion Inviscid & Incompressible Flow of Aerodynamics

Answer 1

Right option is (b) equivalent airspeed

Explanation: Equivalent airspeed refers to the speed of an aircraft at which it should fly so as to maintain the same dynamic pressure. In the above example, 65m/s is the equivalent airspeed at an altitude of 10km flying with a true airspeed of 110 m/s.