Which of the following is correct for hinge moment?

Lifting property of the airfoil is same as a sphere

Hinge moment is not dependent on the tail angle

Downwash is used to reduces angle of attack at tail

Hinge moment coefficient is function of tail angle of attack

Correct Answer : Hinge moment coefficient is function of tail angle of attack

Explanation : Hinge moment coefficient is function of number of factors such as tail angle of attack, tail setting angle, etc. Due to downwash the angle of attack at tail will be more. Lifting property of an airfoil and sphere will be different. Airfoil is 2d shape and sphere is 3d shape.

Recently Updated in Aircraft Design Questions

Which of the following is not the type of aircraft dynamic mode?

Phugoid

Flap

Dutch roll

Lateral mode

Correct Answer : Option (B) : Flap

Explanation : Flap is a high lift device. Flap is used to increase lift produced by the wing. Flaps are used to increase camber and overall surface area of the wing. This results in increased lift. Dutch roll, phugoid, lateral mode etc. are typical aircraft dynamic modes.

Which of the following is an example of longitudinal mode?

Dutch

Lateral

Phugoid

Aileron

Correct Answer : Option (C) : Phugoid

Explanation : Phugoid mode is an example of longitudinal mode. Dutch and lateral mode are not example of longitudinal mode. Aileron is known as primary control surface. Aileron is used to control the aircraft rolling moment.

Find critical damping coefficient if damping ratio is 0.5 and damping coefficient is 1.1.

2.2

4.1

4.9

5.2

Correct Answer : Option (A) : 2.2

Explanation : Critical damping coefficient damping coefficient/ damping ratio 1.1/0.5 = 2.2.