Question

Jet aircraft with CD=0.01+0.02CL^2 is performing loiter. Find wing loading for maximum loiter if, AR=8.5, e=0.7 and dynamic pressure is 25Pa.

(a) 10.80

(b) 11.80

(c) 12.80

(d) 13.08

I have been asked this question at a job interview.

My question comes from Wing Loading topic in portion Thrust-Weight Ratio and Wing Loading of Aircraft Design

Answer 1

Correct option is (a) 10.80

For explanation I would say: Given, CD = 0.01+0.2CL^2, AR=8.5, e=0.7, Dynamic pressure q=25Pa.

From CD = 0.01+0.2CL^2, CD0 = 0.01.

Wing loading for maximum loiter is given by,

W/S = \(q*\sqrt{\pi eARCD0}\) = W/S = 25*\(\sqrt{\pi*0.7*8.5*0.01}\) = 10.80.