Principles of Flight (Helicopter) - PPL(H) - Private Pilot License

Question 1

Why does a stall begin on the retreating rotor blade at high cruise speeds?

Accepted Answer

The large pitch angle and relatively low peripheral speed cause a large effective angle of attack

Answer

The airflow reaches subsonic speed and causes an increase of the induced drag

Answer

The small pitch angle and a relatively low peripheral speed cause a small effective angle of attack

Answer

The airflow reaches supersonic speed and causes an increase of the parasite drag

Question 2

The helicopter's stability is increased by...

Accepted Answer

Attaching a stabilizer.

Answer

Reducing the rotor RPM.

Answer

Pivoting the drag hinge.

Answer

Decreasing the rotor mass.

Question 3

What is caused by an increase of stability in a helicopter?

Accepted Answer

A relief of the pilot in command

Answer

A decrease of the required control forces

Answer

An enhance of control under all load factors

Answer

An optimization of the maximum helicopter mass

Question 4

The effective airflow velocity of a rotor blade element varies with the distance from the rotor shaft axis, because the...

Accepted Answer

Peripheral speed increases if the displacement to the rotor blade tip decreases-

Answer

Helicopter airframe disturbs the airflow.

Answer

Tangential force and airflow reversal vary.

Answer

Drag force in direction of the rotaion axis is increased.

Question 5

What is the reason for the driving forces in an autorotation?

Accepted Answer

Downward tilted effective airflow

Answer

Low rate of descent

Answer

Increased pitch angle

Answer

High airspeeds

Question 6

Which of the following options has an effect on the autorotation characteristics?

Accepted Answer

Helicopter mass and density altitude

Answer

Smoothly working tail rotor control and low RPM warning systems

Answer

Air temperature and wind speed

Answer

Pressure altitude and wind speed

Question 7

The maximum range in an autorotation will be achieved by...

Accepted Answer

A relatively high effective angle of attack.

Answer

A relatively low effective angle of attack.

Answer

A neutral effective angle of attack.

Answer

A negative effective angle of attack.

Question 8

During hover flight, the induced airflow velocity...

Accepted Answer

Increases further having passed the rotor.

Answer

Is equal above and below the rotor.

Answer

Remains constant after having passed the rotor.

Answer

Decreases after having passed the rotor.

Question 9

What causes the phase lag between the displacement and the flapping of a rotor blade?

Accepted Answer

Inertia, mass, and aerodynamic forces

Answer

Rounding of the rotor blade tips

Answer

Friction in the rotor blade spindles

Answer

Advance or retreat angle of 90°

Question 10

Why are the stability criteria of a helicopter very important?

Accepted Answer

A lack of stability may lead to loss of control

Answer

Low stability reduces the available control forces

Answer

High stability prevents low load factors

Answer

Large stability increases the maximum take-off mass

Quiz Principles of Flight (Helicopter) - PPL(H) - Private Pilot License

Test 10 Questions PPL(H) - Private Pilot License - Principles of Flight (Helicopter), no time limit