POH 4.8 Fuel System

Question 1

POH.4.8.1 Fuel Tanks

Question 2

Where is fuel stored?

Answer 2

Fuel is stored in fuel tanks located in each wing.

Question 3

How are tanks interconnected in each wing?

Answer 3

The tanks in each wing are interconnected to function as a single tank.

Question 4

How are tanks filled?

Answer 4

All tanks on each side are filled through a single filler in the outboard tank, and as fuel is consumed from the inboard tank, it is replenished by fuel from outboard.

Question 5

What’s the unusable fuel?

Answer 5

2.5 Gallons

Question 6

How much is it usable?

Answer 6

93 gallons with standard fuel tanks

123 gallons with the optional fuel tanks installed

Question 7

What’s the minimum fuel grade?

Answer 7

100 or 100LL Aviation Grade

Question 8

What about Flyschool’s tanks?

Answer 8

FlySchool have optional tanks installed. The usable fuel is 123 gallons.

Question 9

What are the fuel tank vents?

Answer 9

one installed under each wing, feature an anti-icing design to prevent ice formation from blocking the fuel tank vent lines

Question 10

POH.4.8.2 Fuel Injection System

Question 11

What type of fuel injection does the Seneca II use?

Answer 11

Continuous flow type that utilizes a vapor return line leading back to the fuel tanks.

This line provides a route back to the tanks for vapor laden fuel that has been separated in the injector pump swirl chamber.

Question 12

How many pumps does each engine have?

Answer 12

Each engine has an engine-driven fuel pump that is a part of the fuel injection system.

An auxiliary fuel system is provided. The purpose of the electrically powered auxiliary fuel system is to supply fuel to the engine in case of engine-driven fuel pump shaft failure or malfunction, for ground and inflight engine starting, and for vapor suppression.

Question 13

Where are the two auxiliary fuel pump switches located?

Answer 13

The two auxiliary fuel pump switches are located on the lower left side of the instrument panel and are three-position rocker switches: LO, HI and OFF.

Question 14

What happens when the HI auxiliary fuel pump is activated?

Answer 14

When the HI auxiliary fuel pump is activated, an amber light in the annunciation panel is illuminated for each pump. These lights dim whenever the pump pressure reduces automatically, and manifold pressure is below approximately 21 inches.

Question 15

POH.4.8.3 Electric Primer System

Question 16

What does the primer switch do?

Answer 16

Separate spring loaded OFF primer button switches, located adjacent to the starter switches, are used to select HI auxiliary fuel pump operation for priming, regardless of other switch positions. These primer buttons may be used for both hot or cold engine starts.

Question 17

POH.4.8.4 Fuel Drains

Question 18

Why are fuel drains carried out and when?

Answer 18

Before each flight, fuel must be drained from low points in the fuel System to ensure that any accumulation of moisture or sediment is removed from the system and to check for proper fuel. Fuel drains are provided for each fuel filter (2). each fuel tank (4), and each crossfeed line (2).

Question 19

POH.4.8.5 Fuel Controls

Question 20

Where are fuel controls located?

Answer 20

Fuel management controls are located on the console between the front seats.

Question 21

How do the fuel controls work?

Answer 21

There is a control lever for each of the engines, and each is placarded ON - OFF - X FEED. During normal operation, the levers are in the ON position, and each engine draws fuel from the tanks on the same side as the engine. The two fuel systems are interconnected by crossfeed lines. When the X FEED position is selected, the engine will draw fuel from the tanks on the opposite side in order to extend range and keep fuel weight balanced during single-engine operation. The OFF position shuts off the fuel flow to that engine.

Question 22

What must you note about the fuel control when one engine is inoperative?

Answer 22

When one engine is inoperative and the fuel selector for the operating engine is on X FEED, the selector for the inoperative engine must be in the OFF position.

Question 23

What musn’t you do?

Answer 23

Do not operate with both selectors on X FEED. Do not take off with a selector on X FEED. Fuel and vapor are always returned to the tank on the same side as the operating engine