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I believe that the A-10 burns JP-8 fuel. I once read that the older JP-4 fuel was a mixture of kerosene and regular grade gasoline. What is different about JP-8? Is it a special blend for turbofan engines? What is it composed of?

Thanks,

Bob

JP-4 and JP-8 are both kerosene, but JP-8 has an additive in it...can't remember what it is. But JP-8 is heavier, a full load of JP-8 is 11,200lbs and JP-4 is 10,500lbs. Standard day temperature, of course.

Coach

Every AF jet uses JP-8. I believe the Navy still uses JP-4 but I could be mistaken. We have used other stuff occasionally, this past spring we used somethign else in Bagram b/c it was a little bit lighter. I cant remember what it was called. It really screwed with all the fuel totalizers though, nothign but problems. I believe JP-8 is identical to commercial A-1. I've put A-1 on the jet before and it works fine anyway. The total max fuel load accordign to the 781F is I think 10,924lbs. Every jets totalizer reads differently though, anywhere from 10,800 to 11,400.

Liberalism is a mental disorder.

JP-4 (the JP is for jet petroleum) is what is called a wide cut fuel. It is a mixture of 35% kerosene and 65% avgas for understanding. It is the same as commercial Jet-B fuels. The advantages of wide cut fuels are there extremely low flash point and boiling point which is beneficial when attempting a re-start at higher altitudes if you loose an engine. However on the ground it can be pretty nasty if not treated with great care. Wide cut fuels also weigh less, or have a lower specific gravity compared with narrow cut fuels.

"By this time tomorrow I shall have gained either a peerage or Westminster Abbey !" Nelson the Immortal Memory

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When did they go to JP-8? I never put JP-8 in a JET unless we were TDY . It was always JP-4.


gOOSE


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<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>When did they go to JP-8? I never put JP-8 in a JET unless we were TDY . It was always JP-4. <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I'm thinking mid to late 90's Goose and it's now the Air Force standard though I think the Navy is using JP-5. I haven't seen JP-4 in years.

OC

Some days it's hardly worth chewing through the restraints

Hawg166 gave the formula for JP-4 as 35% kerosene and 65% av gas. Is JP-8 basically the same except for the additives?

Bob

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Hawg166 gave the formula for JP-4 as 35% kerosene and 65% av gas. Is JP-8 basically the same except for the additives? <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

No Bob, JP-8 is almost pure kerosene (99.8% by weight). The .2% is made up of various additives for anti-icing, corrosion inhibitors and some other stuff.

OC

Some days it's hardly worth chewing through the restraints

Chief is correct.

"By this time tomorrow I shall have gained either a peerage or Westminster Abbey !" Nelson the Immortal Memory

_________________
YGBSM !

Thanks, guys, for the good info.

Bob

IIRC, 30MM Jr said they went to JP-8 for the reason Hawg166 stated: boiling flash points; i.e., safety issues.

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<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>When did they go to JP-8? I never put JP-8 in a JET unless we were TDY . It was always JP-4. <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I'm thinking mid to late 90's Goose and it's now the Air Force standard though I think the Navy is using JP-5. I haven't seen JP-4 in years.

OC

Some days it's hardly worth chewing through the restraints
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

We were using JP-8 when I got in in 94...

<img src="http://img23.photobucket.com/albums/v70/prkiii/70th.jpg" border=0><img src="http://img23.photobucket.com/albums/v70/prkiii/Mav_shot.jpg" border=0><img src="http://img23.photobucket.com/albums/v70/prkiii/25.jpg" border=0>

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Thats pretty wild they changed to JP-8 after all those years.

Goose

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Being an old engine troop all I know is that I like the smell of JP-4 a lot better than JP-5 or JP-8. <img src=icon_smile_approve.gif border=0 align=middle>

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WOW, it looks like you're teaching crew chief 101 rather than an overview of the A-10 itself. All I can add is be sure to put in some history of the A-10's service so the people at Owego can get that personal connection with the airframe and the people who support, fly and maintain the her.

Visit my A-10 website at
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No problem there, Dice. I'm going to give everyone a full history of the A-10's lineage, plus a lot of other details about the plane. I'm going to cover the engines as part of the classes, and or course, when you talk about engines, you need to mention what fuels them. I thought it was still JP-4 until I came across a photo of a fuel truck here on Warthog Territory with the sign JP-8, parked in front of an A-10. So I thought I'd better ask the question instead of guessing and telling people the wrong thing. (Plus I've learned some good stuff on this subject, too)

Bob

Bob - Where exactly in Owego do you work? My brother is working for Lockheed in Owego now.

Liberalism is a mental disorder.

Edited by - jackb on Dec 12 2006 18:23

I'm doing my training class work for the Systems Engineering area, which is probably where your brother is working. I'm not a full time employee - I'm what's referred to as "casual part time". What that means is that I can work whenever they need me, up to 999 hours per year, and still collect my retirement income. I guess that's some kind of Federal law. But after being retired for ten months, "work" is definitely a four-letter word. Once the training classes are done, I doubt that they will be able to entice me to come back again. I just agreed to do this because the Hog is my favorite thing next to food and air, and I really like to spread the word about it. And thanks to all of you who are helping me do it!

Bob

Sounds good Hag Fan, you may also want to go to Flight Chief dot com (link below) and pull down a music video or two for motivalional material.


http://www.flightchief.com/videos/

Visit my A-10 website at
http://www.warthogpen.com