SIFT Principles of Helicopter Flight 2

Question 1

What is translational lift in helicopter flight?

Accepted Answer

Lift generated by forward flight that improves rotor efficiency

Answer

Translational lift occurs when forward airspeed moves the rotor out of its own downwash, allowing each blade to encounter undisturbed air and generate more lift.

Question 2

What is the primary purpose of the tail rotor on a single-rotor helicopter?

Accepted Answer

To counteract the torque produced by the main rotor

Answer

The tail rotor produces thrust opposite to main rotor torque, preventing the fuselage from spinning in the opposite direction.

Question 3

During autorotation, how does the pilot control rate of descent?

Accepted Answer

By adjusting collective pitch

Answer

The pilot uses collective pitch to manage rotor RPM and control the rate of descent during autorotation.

Question 4

What is gyroscopic precession as it applies to helicopter rotors?

Accepted Answer

A force applied to a spinning rotor acts 90 degrees later in the direction of rotation

Answer

Gyroscopic precession means a force applied to a spinning disc takes effect 90 degrees in the direction of rotation from the point of application.

Question 5

What is blade flapping in a helicopter rotor system?

Accepted Answer

The up-and-down movement of blades to equalize lift between advancing and retreating sides

Answer

Blade flapping allows rotor blades to rise on the advancing side and descend on the retreating side to compensate for dissymmetry of lift.

SIFT Exam Practice Test

SIFT Exam Practice Test

SIFT Principles of Helicopter Flight 2