Fuel Systems

Question 1

What is the total useable fuel
(Wings and fuselage)
Is there a difference if you use SPPR?

Answer 1

Total:7910
Wings:1449 (1400 using SPPR)
Fuselage:5012 (5000 using SPPR)

Question 2

How many Jet pumps are there?

Answer 2

1 main jet pump per wing

3 transfer jet pumps per wing

Question 3

At what point would trigger the low level float switches? What will happen once low fuel is detected?

Answer 3

Low level float switches trigger at 410lbs of fuel remaining on either wing. Once low fuel is detected scavenge pumps will activate and 30 seconds later a low fuel annunciation will illuminate on the cockpit glare shield panel. Also this will trip the “fill” function to the off position

Question 4

How many quantity probes are located in the total fuel system?

Answer 4

9 probes total
4 left wing (1 inboard probe has temp compensator attached just on the left wing)
4 right wing
1 fuselage

Question 5

What does (Error code) ER-5 indicate if displayed in the cockpit indicator?

Answer 5

Fuel has possibly become contaminated

Question 6

What does (Error code) ER-8 indicate if displayed?

Answer 6

Loss of aircraft pitch information

Question 7

If your main Jet pump fails what else will you lose? What will you do? What is the unusable fuel amount at that point?

Answer 7

You will lose jet transfer pumps.
Turn off FILL OR GRVTY
Turn on STBY PUMPS.
400lbs of fuel will become unusable.

Question 8

You see L OR R ENG FILTER annunciation illuminate on the cockpit glare shield display. What has happened?

Answer 8

One or more of the engine fuel or oil filters have an impending bypass.

(Note: Bypass of a secondary fuel filter will only illuminate on the ground)

Question 9

What principle do the Jet pumps operate on? (Electrical? Hydraulic?)

Answer 9

The jet pumps operate on the Venturi principle. The require no electrical power and have no moving parts. Fuel comes in @400psi and goes out @12psi

Question 10

How fast does the NORM & AUX pumps transfer fuel?

Answer 10

50lbs per minute

100lbs per minute with both on (rapid transfer)

Question 11

With gravity transfer on how much fuel is unusable in the fuselage? How is it possible to transfer the rest?

Answer 11

350lbs
Turn GRVTY off
Turn NORM/AUX pumps on

Question 12

What pumps remain useable during EMER BUS mode operation?

Answer 12

NORM & AUX transfer pumps

Question 13

During SPPR ops what is the normal range (psi) that should be displayed on the truck?

Answer 13

20-60 PSI

Question 14

What conditions would cause Fill function to turn off?

Answer 14

You physically turn it off
Weight off wheels
Fuel in left wing is 410lbs
Fuselage tank is full

Question 15

What is the limitation for fuel imbalance on the ground? What about in flight?

Answer 15

For T/o and landing: Max 200lbs

For Enroute: Max 500lbs

Question 16

If outside temp is below -40°C how much fuel should be kept in each wing?

Answer 16

No more than 800 per side, fuel is kept warmer closer to fuselage.