Question

What is the indicated temperature of an aircraft having mach number 2 and when temperature and recovery factor are 300K and 2?

(a) 780K

(b) 128K

(c) 345K

(d) 435K

I have been asked this question in an internship interview.

The doubt is from Measurement of Air Temperature topic in section Atmosphere and Air Data Measurement of Aircraft Performance

Answer 1

The correct choice is (a) 780K

The best explanation: The answer is 780K. Given r=2, T=300K, M=2 and we know that γ for air is 1.4. From the formula Ti=T[1+r\(\frac{\gamma-1}{2}\)M^2].

On substituting the values we get Ti=300[1+2\(\frac{1.4-1}{2}\)2^2]

On solving above equation we get Ti=780K.