Rotorcraft Fundamentals

Question 1

Which has the more critical center of gravity range, an airplane or a helicopter?

Answer 1

A helicopter.

Question 2

What causes dissymmetry of lift produced by the rotor of a helicopter?

Answer 2

The forward speed of the helicopter produces dis-symmetry of lift. The rotor blade which is traveling forward as the helicopter is flying produces more lift than the blade that is traveling rearward.

Question 3

Why do single-rotor helicopters use an auxiliary rotor on their tail?

Answer 3

The thrust from the auxiliary rotor on the tail of the helicopter counteracts the torque produced by the main rotor.

Question 4

Why is it important that the blades of a helicopter rotor system be in track?

Answer 4

If the blades are not in track, vertical vibration can develop.