Systems

Question 1

Describe the engines in the PA 34-200 Seneca 

Answer 1

Both engines are Lycoming 
Right Engine: LIO- 360
Left Engine: IO-360

Four-cylinder / horizontally opposed / normally aspirated / air cooled / direct drive / fuel injected / 200 BHP /
2700 RPMS / 8 qts oil capacity

Question 2

Describe the propellers

Answer 2

• Manufactured by Hartzell
• Counter rotating
• Constant speed full feathering propeller

Question 3

What is alternate air?

Answer 3

Alternate air works as carburetor heat. Heated air around exhaust manifold is directed through the alternate air source. RPM drops slightly when it is open.

Question 4

What is a constant speed propeller?

Answer 4

A constant speed propeller maintains the rpm selected by the propeller control lever.

Question 5

How does a constant speed propeller work?

Answer 5

When the airplane raises its nose, it starts to climb. As it climbs, air speed goes down. The RPM is also going to go down due to increase drag on the blade. However, blade angle is decreased automatically to reduce the drag to maintain a constant RPM.

When the airplane drops its nose, it starts to descend. As it descends, air speed will increase. The RPM is also increased due to decreasing drag on the blade. However, played angle is increased. Automatically to decrease the drag and maintain a constant RPM.

Question 6

Where is the governor located?

Answer 6

In front of the engine

Question 7

What does the governor do?

Answer 7

The flyway inside the governor senses, the change in RPM through centrifugal force. When RPMs increase a valve opens draining oil out of the propeller hub to increase blade angle. When the RPM decreases a different valve opens a line with a pump. The pump send oil to the propeller hub to decrease the blade angle. 

Question 8

What makes the propeller blade high pitch?

Answer 8

Nitrogen charged in the hub and a counterweight at the root of the propeller blades 

Question 9

What makes the propeller blade low pitch?

Answer 9

High pressure of the oil and aerodynamic force on the propeller 

Question 10

What happens when the pilot moves the propeller lever inside the cockpit?

Answer 10

Tension on the speed or spring changes. High tension requires more centrifugal force on the fly weight, increasing the RPMs. Low tension requires less of typical force on the fly weight, decreasing the RPMs. 

Question 11

Describe the fuel system

Answer 11

• 100 / 130 octane aviation gasoline
• 2 fuel tanks on each side (4) total
• 2 fuel pumps each side (4) total
(1)engine driven/ (1) electric motor
• 98g total / 93g usable
• max fuel flow, 19.2 GPH.
• Fuel pressure 14 psi to 35 psi

Question 12

When are the electric fuel pumps used?

Answer 12

• On engine start up
• Take off, climb out and landing
• When the engine driven pump is in operative

Question 13

How do you send fuel from the right tank to the left engine? 

Answer 13

Select crossfeed on the left fuel selector valve. The POH says fuel selector valve for the inoperative engine should be off.

Question 14

When can you use the crossfeed function?

Answer 14

Only in Cruz 

Question 15

Can you select crossfeed on both engines?

Answer 15

No

Question 16

What is the purpose of cross feeding fuel?

Answer 16

To balance, the weight laterally when one engine is in operative and for longer range endurance.

Question 17

How do you feather the propellers?

Answer 17

Feathering of a propeller is accomplished by moving the control, fully aft, through the low rpm detent, into the feather position. Feathering takes place in approximately six seconds.
If engine is less than 800 RPM, a feathering lock will prevent the propeller from feathering.

Question 18

How do you unfair there a propeller?

Answer 18

Unfettering a propeller is accomplished by moving the propeller control head and engaging the starter until the propeller is windmilling.