Info sur Fuel system

[Jallie]

Quote:
Originally Posted by ~*Panther*~
NO! That switch just tells you what your quantity is in those tanks selected. It has no effect on the fuel and where it is transferred to. The fuel in the external tanks is feed to the engine first. Even real pilots think that switch transfer the fuel, it doesn't. I don't understand what they teach them in Pilot training.


Not quite Panther, the Fuel QTY Selection Knob gives the fuel quantity of the tank selected.

NORM: Total fuel quantity in the F-16
RSVR: Fuel Qty in Fuel Tank Resevoirs
Int. Wing: Fuel Qty in the Wing Tanks.
Ext. Wing: Fuel Qty in the Ext Wing Tanks
Ext. Center: Fuel Qty in the Centerline Wing Tank

(This is handy for checking for fuel imbalance or leaks)

The Fuel QTY Switch has nothing to do with fuel transfer or fuel measurement. It's function is to determine which External Fuel Tank the fuel is drawing from first:

Norm: The Center Tank is emptied first, then the Wing Tanks
Wing First: The Ext. Wing Tanks transfers first, then the center tank



Quote:
Originally Posted by MuraD

how do the external fuel tanks work then?



When set to NORM on the Environmental Control System (ECS), the air flows through check valves to the external wing tank vents and presurization valves. That is when pressure is reduced and supplied to the wing tanks. (This is also where the Halon Fire System is located, if there was an Engine Fire, the Halon is injected in this pathway to reduce the fire and prevent an explosion).


Quote:
Originally Posted by MuraD

it is possible to run out of fuel with an improperly set air source knob while carrying external fuel tanks...



Not likely.

With it off, you will still have fuel being supplied to your engines because of the pumps are still supplying fuel flow from your internal fuel tanks. But without it on you are at risk of an explosion hazard because at high altitudes your fuel could vaporize.

Also with the ECS off, your fuel transfer process out of the wing tanks would not be efficent. [People do not realize that aircraft do not draw fuel directly from the External Tanks, but rather move it from the External Tanks to the Internal tanks (keeping it full)]. So if the ECS was off, you would still have fuel in your wing tanks, but also not keeping the internal tanks 'topped-off'.

But running out of fuel? Not likely, unless you was not monitoring your fuel situation like you should.


FYI: The Air Source Knob:

Off: Engine Bleed Air Valve is closed. All air conditioning, cooling, and pressurization systems are shut off, including the capony seal and fuel tank pressurization. *When off, it will cause damage to avionics due to lack of cooling*

NORM: Normal AC operation over temperature and pressure regulation.

DUMP: Cockpit pressure dump valve is opened to atmospheric pressure.

RAM: Closes bleed valves, AC off, dump valve opens ram valves. Forces ram air into the cockpit for ventilation and avionic cooling. (This is handy when avionics are unusually hot or you have smoke/chemical odors in the cockpit).

As I said previously, the Air Source knob is part of your pressurization system, not your engine. Having it off is unlikely to cause a flame-out, unless you somehow managed to turn off your fuel pumps.



Quote:
Originally Posted by Canadian Kodiak

I don't know exactly how the JFS works, but I know it has to be 'cranked up'. Then it stores a finite amount of power that can be used to start the jet before it has to be cranked up again.




JFS is a gas turbine that vents two hydraulic actuators to the hydraulic start motor. Start 1 = use one actuator, Start 2 = Both actuators (best start). Takes about 1 minute to recharge.
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[Electro]

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