Fuel starvation on a320. Curious.

[z.khalid]

I was just curious and thinking of this earlier.
If you've run out of fuel, surely your engines will flame out, along with generators.
APU isn't even an option obviously.
What is the aircraft now left with?

Just curious, and looking for some input. Thanks guys

[Gulfstream757]

Does the 320 have a RAT,I doubt it though.I'd assume that there is some sort of manual reversion perhaps or a battery driven hydraulic pump?

[Burnie5204]

A320 does have RAT

For the benefit of the OP

RAT - Ram Air Turbine.

A small wind powered generator which provides enough electricity to power basic flight instruments and flight controls

[captainpeter]

It does.

The RAT is released automatically IF AC bus 1 AND AC bus 2 are without power AND aircraft in flight. (It needs more than 100kts airspeed to work but any slower than that and you have other things to worry about)

Powers the blue system if extended which gives you hydraulics + enough juice to operate the flight controls.

peter

[Gulfstream757]

It does oh interesting,well you know what assuming does.Weird the 737 doesn't though when the 76/57 do have one anyways thanks for the info.

[porch monkey]

737 doesn't need it as it will gravity feed fuel if no a/c power and the flight controls are connected to the surfaces by the old cable method and can do without hydraulics if absolutely necessary.

[z.khalid]

Fair enough, thanks guys.
Now Also, during the time when lost both AC busses, and RAT supplying elec/Hyde power, the aircraft batteries are obviously not charging, correct? So below 50 it's, you've lost full electric supply if your batteries have drained?

And also, Failure of extension of RAT for some reason, then what?
Now you've got I believe about 30 minutes on a good battery.
Now what are we down to?

[pattern_is_full]

Well, according to your scenario, both engines have flamed out.

30 minutes of battery power (if accurate) will be more than enough for the remainder of the flight...err...glide :} - and the least of your worries.

Air Transat 236 - 19 minutes between final engine flameout @ 34,500 feet and landing.

Air Canada 143 ("Gimli glider") ~18 minutes between flameout @ 31,500 feet and landing.

[Dan Winterland]

Technically, the RAT powers the blue hydraullic system which will power the hydraullic driven emergency generator. There is enough hyd and elec power to keep the airaft flying.

However, the winmilling engines will continue to generate enough hyd power for quite a while. In the simulator we use, there's enough airflow through the engines to keep enough hyd power down to about 180 knots. But a mate who had a winmilling engine situation for real said the hyd low pressure ECAM for that engine didn't come on until they had slowed to about 80 knots on the runway.



As for Boeings, I only have experience of the 747 (Both classic and 400). There was no emergency hyd generation at all in the case of a 4 eng flameout - and no RAT. There were air driven pumps for 2 engines (400) all engines (Classic) but you couldn't start the APU in flight, so you were screwed. However, there were a few cases of 4 engine flameouts being survived in the 747 and I can only assume that there was enough windmilling hyd pressure to keep the aircraft flying. Interstingly, the 747-8 does have a RAT.