Fuel System

Question 1

Trapped fuel weight:

Answer 1

Is included in the aircraft basic weight for airplanes certified in the U.S.

Question 2

With exception of the FUEL JTSN lights, all other Amber lights on the fuel control panel, when illuminated steady, indicate that the respective:

Answer 2

Valve position disagrees with the switch

Question 3

The red LOW FUEL light illuminates when

Answer 3

400 to 500 lb remains in either wing

Question 4

The standby pumps are used for all the following functions except:

Answer 4

Wing-to-wing crossflow with a wing tank jet pump inoperative

Question 5

The crossflow valve opens:

Answer 5

Whenever the CROSS FLOW, XFER-FILL, or FUS VALVE switches are moved from the OFF or CLOSE position

Question 6

Steady illumination of an amber transfer valve light indicates:

Answer 6

The valve failed to move to the position commanded by the XFER-FILL switch

(i.e. disagreement)

Question 7

Illumination of the red L or R FUEL PRESS light indicates:

Answer 7

Fuel pressure to the respective engine-driven fuel pump is low

Question 8

When the XFER-FILL switch is placed to the FILL position, the:

Answer 8

Crossflow valve opens

Question 9

Motive-flow fuel for the jet pumps is supplied by:

Answer 9

Engine-driven fuel pumps

Question 10

The amber FUEL Filter light indicates:

Answer 10

That one or both fuel filters are being bypassed

Question 11

The amount of fuel trapped in the fuselage tank after completion of gravity transfer vis the fuselage valve is approximately:

Answer 11

162 lb (24.3 gallons)

Question 12

The wing fuel pressure switch:

Answer 12

Turns off the fuselage transfer pump when wing fuel pressure reaches 5 psi

Question 13

When using any mixture of aviation gasoline:

Answer 13

• Do not take off with fuel temperature lower than -54C (-65F)
• Restrict flights to below 15,000 ft
• Both jet pumps and both standby pumps must be on and the pumps must be operating

Question 14

The Learjet 35/36 requires anti-icing additive:

Answer 14

At all times

Question 15

Maximum demonstrated fuel imbalance is:

Answer 15

600 lb tip tanks

Question 16

Max Usable Fuel

Total:
Fuselage Tank:
Tip Tanks:
Wing Tanks :

Answer 16

Total: 6,238

Fuselage Tank: 1,340

Tip Tanks: 1175 / right and 1215 left - 2390 total

Wing Tanks : 1254 / side - 2508 total

Question 17

Max Tip tank fuel for landing

Answer 17

925 lbs.

Question 18

Do not energize fuselage transfer system when

Answer 18

wing and tip tanks are full

Question 19

Can you cross flow with wing jet pump inoperative?

Answer 19

No, do not do it.

Question 20

How long does it take to Jettison Full Tip Tanks ?

Answer 20

approximately 5 minutes

Question 21

Time to reduce from Max takeoff wt. to max. landing weight is approximately:

Answer 21

40 minutes

Question 22

Max Altitude or suction feed (red FUEL PRESS light illuminated)

Answer 22

25,000 feet.

Question 23

Refueling Considerations:

Fuel flow for proper PRIST mixing:
Max/Min fuel per 20oz. can of PRIST:
Max Tip Tank imbalance during refueling:

Answer 23

Fuel flow for proper PRIST mixing: 30-60 GPM

Max/Min fuel per 20oz. can of PRIST: (Check Fuel Addenda)

Max Tip Tank imbalance during refueling:

Question 24

Approximately how much unusable fuel is in the fuselage tank using alternate transfer (gravity method)

Answer 24

162 lbs.

Question 25

Fuel System Limits:

125 Gallons: 
162 lbs. :
200 lbs. : 
400-500 lbs. : 
500 gallons : 
600 lbs. : 
600 lbs :
760 lbs. or less : 
925 lbs : 
13,500 lbs :

Answer 25

125 Gallons: Service per Tip Tank or fill both tanks simultaneously

162 lbs. : trapped fuel in fuselage tank during gravity transfer

200 lbs. : Max lateral fuel imbalance for use of autopilot

400-500 lbs. : Fuel level in either wing tank illuminates red LOW FUEL Light

500 gallons : AVGAS may not be used in excess of 500 gallons per 100 hours of operation per engine

600 lbs. : Max demonstrated fuel imbalance for landing (one tip tank half full the other empty )

600 lbs : Minimum fuel in each wing for takeoff or intentional go around.

760 lbs. or less : Max Tip Tank quantity before initiating transfer.

925 lbs : Max Tip tank quantity for landing

13,500 lbs : Maximum Zero . Wing and Tip Fuel Weight

Question 26

What does the Delta Fin on an extended range tank 35 do?

Answer 26

lateral stability, as well as preventing a deep stall

Question 27

Do the pumps push or pull fuel?

Answer 27

Push

Question 28

What is the rate of the standby pumps?

Answer 28

50 lbs. / min

100 lbs. / net change

Question 29

Formula to Calculate Vref:

Answer 29

105 – basic starting
+1/2 fuel
+ 1 knot per passenger
+1 knot per 100 lbs

4000 lbs

105 + 20 + 1 pax = 126

Question 30

Rule of thumb Fuel Technique

1st Hour
2nd Hour
every consecutive hour after

Answer 30

1500 – 1st Hour
1300 – 2nd Hour
1100 – every consecutive hour after

Question 31

High pressure stage pump uses

Answer 31

Motive flow (regulated to 300 PSI)

Question 32

Jet pump send fuel

Answer 32

directly to inboard wing

Question 33

Less than .25 psi the

Answer 33

Low-pressure fuel switch activates and low-pressure fuel light will illuminate. Indicates whether motive flow is working or not, hence the low number. It either is or it isn’t.

Question 34

Standby Pump average PSI

Answer 34

18-21

Question 35

when fuel filter is being bypassed you get the FUEL FILTER light. This fuel filter is located

Answer 35

in the tailicone.

Question 36

Engine fuel filters are being bypassed

Answer 36

the pin on the nacelle.

Question 37

Fuel SOV is located

Answer 37

in the tail cone

Question 38

Standby pump and Fuselage pump are cooled by

Answer 38

The fuel they sit in

Question 39

White empty light indicates fuel pressure in transfer line is less than

Answer 39

2.75PSI.