How do fuel gauges work on fighter aircraft?

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (Admiral Beez) — Tue, 13 May 2008 19:02:44 GMT

Michael Hoddy wrote:
At least in USAF tankers (don't know about others), once the plane gets on the boom, there's also a closed-circuit com link available between the boom operator and the plane on the boom to allow communication without going on the radio.

Ah, now that makes sense.

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (radiationhazard) — Tue, 13 May 2008 18:30:32 GMT

I know some civilian aircraft have capacitive fuel sensors in the tanks (though those might only work effectively in level flight). I would hazard a guess that most fighters have them as well, to supplement any fuel-flow based system.

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (Michael Hoddy) — Tue, 13 May 2008 04:08:29 GMT

Admiral Beez wrote:
How do you measure fuel load during in-flight refueling, especially during radio silence? Presumably you could hold up a note saying I just gave you 500 gallons?

At least in USAF tankers (don't know about others), once the plane gets on the boom, there's also a closed-circuit com link available between the boom operator and the plane on the boom to allow communication without...

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (Admiral Beez) — Tue, 13 May 2008 01:15:12 GMT

It was a mate's bike. My own machine, a 1969 Triumph T100S does have a gauge, nor a reserve petcock so you know you're out of gas when she stops. When I lived in Fredericton I never passed a gas station, even if I needed only a litre or two since once you were in the woods, you never knew when your next fill up was.

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (Red Admiral) — Tue, 13 May 2008 00:50:56 GMT

You've got a bad gauge on your bike. Fuel gauges are overdamped so that vibrations do not cause the indicator to move. If you lay the bike on its side for a few minutes, the gauge should move, but from normal road use it shouldn't make a difference. With period aircraft you'll most likely have a similar system, with possibly more damping to compensate for the greater motion.

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (Alexius55) — Mon, 12 May 2008 23:11:09 GMT

Couldn't the fighter just measure flow rate through the pipe from IFR probe/receptacle to tanks and integrate over time, just like with fuel use? Also, IFR is usually carried out during straight and level flight -I have heard of cases of it being done in a shallow dive, but nothing more challenging to a fuel gauge than that. Incidentally, the shallow dive was Victors refuelling C-130s flying from Ascension to the Falklands and back (36 hours) in 1982. The minimum speed of the Victor was...

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (Admiral Beez) — Mon, 12 May 2008 22:29:59 GMT

How do you measure fuel load during in-flight refueling, especially during radio silence? Presumably you could hold up a note saying I just gave you 500 gallons?

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (bager1968) — Mon, 12 May 2008 20:42:39 GMT

Commercial aircraft are also subject to such errors.

The B767 calculates its fuel state by flow-meters in each engine, which accurately measure how much fuel is used. This total is subtracted from the fuel loaded, giving fuel remaining.

If the initial number is wrong, then bad things happen... Google "Gimli Glider" for one such incident.

http://en.wikipedia.org/wiki/Gimli_Glider

Re: How do fuel gauges work on fighter aircraft?

feeds@yuku.com (emc) — Mon, 12 May 2008 20:19:26 GMT

Admiral Beez wrote:
I was looking at a fuel gauge on a motorcycle, and realized that whenever the bike leaned, the gauge would misread the fuel level, as the float in the tank would be affected by the leaning motion. This got me thinking that on a fighter aircraft, measuring the fuel in the internal and external tanks by either a float or weight system would be even more flawed due to the changes in gravity-forces. If the...

How do fuel gauges work on fighter aircraft?

feeds@yuku.com (Admiral Beez) — Mon, 12 May 2008 19:00:50 GMT

I was looking at a fuel gauge on a motorcycle, and realized that whenever the bike leaned, the gauge would misread the fuel level, as the float in the tank would be affected by the leaning motion. This got me thinking that on a fighter aircraft, measuring the fuel in the internal and external tanks by either a float or weight system would be even more flawed due to the changes in gravity-forces. If the fighter is upside down or turning sharply, does the tank or gauge compensate? Or, is the...