Aircraft Systems - Propellers

Question 1

What type of propellers does the Piper Seminole Have?

Answer 1

Hartzell two bladed, controllable Pitch, constant speed, full feathering propellers

Question 2

What does controllable pitch propeller mean?

Answer 2

It means that you the pilot can adjust the angle and pitch of the propeller blades for a specific RPM setting.

Question 3

How does a pilot adjust the propellers pitch?

Answer 3

There is a blue propeller lever that can be pulled aft or pushed forward. There is oil pressure that is regulated by a prop governor, that drives a piston which in turn moves the blades.

Question 4

What happens when you move the blue propeller controller forward?

Answer 4

Oil pressure drives a piston, which moves the propeller blades to a low pitch. A low pitch equals high RPM which is known as an unfeathered position.

Question 5

What happens when the blue prop controller is moved down?

Answer 5

The Oil pressure is reduced from the prop governor, which allows a nitrogen charged cylinder, spring, and counterweight to drive blades into a feathered position, high pitch or low rpm setting known as a feathered position

Question 6

What does it mean that our propeller is constant speed?

Answer 6

Once the propeller RPM setting is selected by the blue lever, the propeller governor will automatically vary oil pressure to maintain a constant engine RPM

Question 7

How long does it take for our propeller to feather?

Answer 7

Approximately 6 seconds

Question 8

How do you feather the prop?

Answer 8

Move the propeller controller all the way aft

Question 9

When Feathering a propeller what must be done to the mixture?

Answer 9

It must be cut off to avoid power or combustion of the engine

Question 10

What is the lowest RPM setting our propeller will feather?

Answer 10

950 RPM

Question 11

How is Pitch controlled in the the aircraft?

Answer 11

Pitch is controlled by Oil and Nitrogen.

Question 12

What does the oil pressure in the propeller do?

Answer 12

It moves the propeller toward the high RPM setting

Question 13

What does the nitrogen pressure do in the propeller do?

Answer 13

Along with a spring the nitrogen pressure puts the propeller in a low RPM or feathered position

Question 14

What does the prop governor do?

Answer 14

Maintains selected RPM setting, or changes the propellers angle. It adjusts the oil pressure and nitrogen pressure

Question 15

How long does it take to feather the propeller?

Answer 15

It takes, roughly 6 seconds

Question 16

What are the engine controls?

Answer 16

The engine controls are the Throttle, Mixture, and Propeller control

Question 17

What does the Throttle control?

Answer 17

The Throttle controls the Manifold Pressure. If it is in between 12 and 18 MP, the gear up warning system will go off

Question 18

What is the purpose of the gear up warning system?

Answer 18

Warns you if your landing gear is not retracted, in low manifold pressure settings. So you do not land with your gear up.

Question 19

What is the purpose of the Propeller Control?

Answer 19

Adjust the blades from either high RPM (low pitch), or Low RPM or feather position (high pitch)

Question 20

What does the mixture control do?

Answer 20

Controls the air to fuel ratio.