Fuel System Flashcards
Outboard tank capacity
Inboard?
1606
1671
- Wing tank gauge quantity indication
- Tank 5?
- totalizer?
12 * 1000 lbs
18 * 1000 lbs
0-66,000 lbs
Boost pump px
15-30psi
Booster (transfer) element rate
Scavenge rate?
5,000lbs per hour
3,000lbs per hour (2500 under 0 backpx)
Engine fuel temp range
40-70F
TD Modes of operation Start Limiting
- engine rpm
- power lever
- take possibility
- put possibility
- TIT limit
- Delivered fuel
<94% N/A 50% 0% 830C 50-100%
TD Modes of operation Temp Limiting
- engine rpm
- power lever
- take possibility
- put possibility
- TIT limit
- Delivered fuel
>94% <66 coord 20% 0% 1,077C 80-100%
TD Modes of operation Temp Controlling
- engine rpm
- power lever
- take possibility
- put possibility
- TIT limit
- Delivered fuel
>94% >66 coord 20% 15% 1,077C 80-115%
How many valves in the Crossfeed system?
4
And 1 crosship
Refuel at how many gallons per minute?
PSI?
600 gpm (300 each) 55psi
Safety feature of the transfer pump dual check valve purpose
Prevents reverse flow through an inop transfer pump due to a failure and during fueling ops. Designed so that only px from an operating pump will open the valve, not suction px.
(Without it, there would be an uncontrolled de fueling from the fuselage section and prevent refueling of other tanks bc of a lack of suction px to open fueling valves
At what psi will the fuel transfer light be illuminated?
Below 4psi
How many lbs per minute can fuel be dumped?
How many pounds can be shed?
1000lbs per min
18,000lbs
How many probes do the outboard tanks have?
Inboard?
Tank 5?
- 5
- 3
- 3 (center section), 1 (bladder forward section)
What nose up attitude will the ball check valve close?
6 degrees
Then the fuselage tank can’t return fuel to the center tank if the wing transfer valves are closed with the transfer pumps running (if below the standpipe)
What happens if there isn’t at least 2000lbs of fuel in center tank 5?
It will not gravity flow thorough the interconnect and the forward transfer pump may cavitate
What could happen if the 4 transfer valves are open in the wing tanks and the fuel level in those tanks is below full?
The valves will accept a high flow rate but the high capacity booster elements of the transfer pumps may evacuate more fuel from the fuselage tank than the scavenge pumps can replace.
Soooo…
Flow through the interconnecting pipe from the center tank to the fuselage tank makes up the different as long as there is a head of fuel in that tank
What does the dual check valve do in the engine tanks?
Prevents fuel from entering the tank during Crossfeed ops when the tank bp is off
What temp does the vernatherm element keep the fuel temp at when passing through the fuel heater/strainer?
40-70F
What does the upper fuel pump assembly housing contain?
- engine driven bp
- secondary pump
- primary pump
What does the lower housing contain?
- secondary pump discharge pressure switch
- two check valves (primary and secondary bypass)
- paralleling valve
- high px filter and it’s bypass
How many thermocouples are there for the TD system?
18
