Question

An aircraft is designed with lift coefficient of 1.1 during steady level flight. If dynamic pressure is set to be 25.65 Pa then find weight of aircraft during this flight condition.

(a) 28.215 N per unit area

(b) 30 kg

(c) 59 N

(d) 125.25 N

I had been asked this question in quiz.

This intriguing question comes from Flight Mechanics topic in section Performance and Flight Mechanics of Aircraft Design

Answer 1

The correct choice is (a) 28.215 N per unit area

For explanation: Given, steady level flight.

Lift coefficient CL=1.1, q=25.65Pa.

Since, area is not mentioned we will find weight as per unit area.

Weight can be given by,

W = q*S*CL = 25.65*1.1 = 28.215 N per area.