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

Question 1

The neutral point is a point where...

Accepted Answer

The torque at the chord line remains constant for changing angles of attack.

Answer

The aerodynamic forces act torque-free.

Answer

The imaginary axes of a helicopter meet each other

Answer

The entire helicopter mass can be assumed to attack.

Question 2

What happens to thrust and tangential force if the rotor RPM decreases by about 10 % in cruise flight?

Accepted Answer

The thrust and the tangential force decrease

Answer

The thrust and the tangential force increase

Answer

The thrust decreases and the tangential force remains constant

Answer

The thrust remains constant and the tangential force increases

Question 3

What relieves the helicopter in a low G manoeuvre?

Accepted Answer

Increased vertical airflow through the rotor

Answer

Weightlessness of the passengers during the push over

Answer

Rolling movement of the helicopter to the right

Answer

Centrifugal force in parabolic flight during the entire manoeuvre

Question 4

If the critical angle of attack is exceeded, the...

Accepted Answer

Boundary layer on the upper side of the rotor blade begins to separate.

Answer

Transition point starts moving towards the airflow direction.

Answer

Boundary layer on the lower side of the rotor blade begins to separate.

Answer

Laminar boundary layer turns into a turbulent boundary layer.

Question 5

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 6

A delta-three hinge is used to allow...

Accepted Answer

For a decreased pitch angle at an upwards flapping blade.

Answer

The advancing blade to flap up about the hinge.

Answer

The advancing blade to lead about the hinge.

Answer

The advancing blade to drag about the hinge.

Question 7

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

Question 8

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 9

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 10

A helicopter with a rotor turning in an anti-clockwise direction seen from above, hovers sideways to the right. What is the azimuth angle where the main rotor blades have the biggest pitch angle?

Accepted Answer

180°

Answer

270°

Answer

90°

Answer

0°

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