Fuel Flashcards
Where does fuel supply
Always the wings, so it feeds to wings always
Does it have dc pumps
Yes to assist ac pump plus feed apu, primary job is to feed ac pumps
Ones aux pump start automatically
Yes when primary pump is switched off
Is crossfeed sov automatic
Yes
What is recirc
Recirc fuel to warm fuel
On fuel page what is green figure
What has been used and
Are feed and transfer same pipes
Yes, changed by valve selection
What fuel levels
Hi-hi,low-low
How is fuel vent stopped
Dc pump in vent system
What is hi-hi
Manual refuelling
Where is surge box
By door l/h and r/h side
How are fuel tank vents arranged
All fuel tanks are vented through an open system of large diameter vent lines within the tanks and fuselage. These lines connect all tanks to two surge boxes within the left and right fuselage sidewalls. Each surge box is connected to a vent outlet port on its respective left or right wing lower surface.
What are dive and vent lines
Each wing tank is connected to the surge box by a main vent line (also called the “dive” vent). It extends from the wing compartment outboard of WS287 to the surge box. It is also connected by an inboard vent line (also called the “climb” vent) which connects the forward portion of the wing tank to the bottom of the surge box. Location of the “climb” and “dive” vent inlets within the wing is such that at least one vent inlet will not be submerged at any aircraft attitude. This ensures unrestricted venting of the wing tank.
What are witness drains
All fuel pressure feed lines inside the fuselage and inside the aft equipment bay are of double walled (shrouded) construction. In the event of a fuel pressure feed line leak, the leaking fuel will be collected by the shroud assembly and drained overboard. The fuel witness drains are located on the fuselage belly fairing between both MLG bay doors and at the aft drain mast assembly located forward of the aft equipment bay door access panel. No leaks are permitted.
Fuel pump electrical conduits that pass through the wing and center fuel tanks are monitored for fuel leakage into the conduit by witness drains. Fuel leaking into an electrical conduit will be indicated by fuel leaking from the witness drain. The witness drains are located on the fuselage belly fairing between both MLG bay doors. No leaks are permitted.
Where does refuel switch get power from
Apu battery with no external power selected
What is fuel press
50psi max
What is sov test
Sends signal to hi-hi and refuel valves and importantly FIDEEX
To check pot fuel isolation valves
Hi-low what does it mean
Fuel tank is empty via sensor
What percentage is hi-low
97 percent
What happens when refuel start switch is pressed more than 5 secs
The gauge gives the fuel that will be loaded
What is lateral imbalance
1100lbs
What is fuel recirculation
Stops fuel freezing, to turn on above 34000ft,
The fuel recirculation system has been installed to permit the Global to conduct long-range, highaltitude flights in cold ambient conditions. The aircraft wing tank fuel must be heated to prevent bulk fuel temperatures from approaching/reaching the freezing point of the fuel. This situation is most likely to occur when the aircraft flies within or across the tropics at high altitude. The engines generate the heat. The hot engine oil is cooled in the FCOC (fuel cooled oil cooler), where the oil heat is rejected into the feed fuel. The FRTT (fuel return to tank) valve allows the hot fuel, downstream of the HP pump, to return to the fuel tank via the A/C fuel recirc system. With the FRTT valve closed, engine internal fuel recirculation is allowed for heat management purposes, as per the already certified baseline A/C configuration.
Once the wing fuel temperature is warm enough (>10°C), a WING FUEL HI TEMP caution message will appear reminding them to turn the system OFF.
What is fuel scavenge
The purpose of the fuel scavenge system is to reduce the amount of unusable fuel in the wing and center tanks. The fuel ejectors are used to recover an additional (approximately) 130 pounds of previously unusable fuel from these tanks. The fuel scavenge system incorporates two subsystems: 1. Wing tank scavenge system 2. Center tank scavenge system
What is wing tank scavenge
Wing Tank Scavenge System The wing tank scavenge system ejectors receive motive flow when the DC AUX PUMPs are in operation (examples: failed AC PRIMARY PUMP, takeoff/landing configuration, low fuel mode). Fuel is scavenged from the left and right wing feed tanks and dumped into their DC AUX PUMP collector boxes. The action of the ejectors keeps the collector boxes full, which maintains the DC AUX PUMPs primed until the fuel is consumed from the wing feed tanks. The DC AUX PUMP collector boxes are an open box sealed at the bottom. They incorporate a flapper check valve to ensure DC AUX PUMP gravity feed in the event a wing tank scavenge ejector fails. The wing tank water drains are located in the DC AUX PUMP collector boxes.
