F-22 internal fuel?

qwe2008 · by **qwe2008** » 25 Sep 2010, 04:11

http://0x4d.net/files/AF1/R11%20Segment%2012.pdf

3082 gallon, 20,000Ib?

popcorn · by **popcorn** » 25 Sep 2010, 05:23

I got 3581.4 gallons internal capacity adding up all the internal fuel cells (transfer and feed).

flyboy22 · by **flyboy22** » 25 Sep 2010, 17:07

nope about 18k internal, 26k with two bags.

BDF · by **BDF** » 25 Sep 2010, 20:00

Yep, the official count is 18,448lbs internal. Not quite sure why the TechOrd shows something different unless one of the smaller tank groups has been intentionally deactivated somehow for some reason. It seems to odd to me too that an official pub was that far off.

djcross · by **djcross** » 26 Sep 2010, 03:18

Usable fuel + ullage volume + unusable fuel = tank internal volume

JetTest · by **JetTest** » 26 Sep 2010, 09:14

It looks like the last notes above are talking gallons vs pounds

sprstdlyscottsmn · by **sprstdlyscottsmn** » 26 Sep 2010, 15:43

I think djcross has it, the other 1600lbs is unusable fuel that will be trapped in the system even if the engines are starved.

sferrin · by **sferrin** » 26 Sep 2010, 18:25

sprstdlyscottsmn wrote:I think djcross has it, the other 1600lbs is unusable fuel that will be trapped in the system even if the engines are starved.

That's sounds like lousy design since you've effectively added 1600lbs of ballast.

shingen · by **shingen** » 27 Sep 2010, 02:33

Heat sink?

lampshade111 · by **lampshade111** » 27 Sep 2010, 03:59

I've heard numbers ranging from 18,000 to 21,000.

flyboy22 · by **flyboy22** » 27 Sep 2010, 13:34

lampshade111 wrote:I've heard numbers ranging from 18,000 to 21,000.

It's 18,000 pounds internal. It's all usable if all the fuel pumps are operating normally.

uclass · by **uclass** » 08 Mar 2016, 13:57

I actually added it up to 13029L, which is about 23504lbs, assuming 0.82kg per lb but DoD say 18,448lbs usable.

uclass · by **uclass** » 08 Mar 2016, 14:05

djcross wrote:Usable fuel + ullage volume + unusable fuel = tank internal volume

So does unusable fuel include the 10% reserve, or is the reserve classed as usable?

sferrin · by **sferrin** » 08 Mar 2016, 14:07

uclass wrote:I actually added it up to 13029L, which is about 23504lbs, assuming 0.82kg per lb but LM say 18,448lbs usable.

Oddly enough, 23,500lbs is the exact difference between empty and loaded weight.

https://en.wikipedia.org/wiki/Lockheed_ ... 28F-22A.29

Something's wrong there. There's no way there's 5000lbs of unusable fuel.

element1loop · by **element1loop** » 08 Mar 2016, 14:31

uclass wrote:
djcross wrote:Usable fuel + ullage volume + unusable fuel = tank internal volume

So does unusable fuel include the 10% reserve, or is the reserve classed as usable?

Unusable is the portion that can not be pumped out of tank to engine. It's usually counted as part of defined aircraft empty weight and normally ignored. The formally given fuel weight is the fully consumable fraction.

Reserve fuel is reserved from the total loaded fuel weight.