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Has anyone seen this phenomena?

I have been on the line for 4 Yrs and never saw a fire ball after shutdown out the engine exhaust. We fly Pratts and use JP8.

If you have seen it is it impressive, loud?

The only thing close is the 229's, which like to smoke some times after shut down which is common for us in the summer months.

Perhaps because after a long mission the engine likes to have a smoke or two... Laughing

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Elite 1K Joined: May 26, 2005 Posts: 1152

From residual fuel vapor in the engine igniting on hot engine parts, or what?

Exactly guysmiley, There is a warning in the TO not to enter the inlet/exhaust for 10Min because of the chance of this, but I have never seen it happen

It used to happen on the earlier types of PW engines, when they had to do a lube and scavenge run. Not all the fuel would get evacuated, and the evaporating and high temps would sometimes cause the fireball. Pretty neat to see actually.

I think the note also says not to stand behind the exhaust, which translates to not bringing your fuel truck up behind the jet for that same 10 minutes, but I can't remember for sure.

Elite 1K Joined: Jan 31, 2004 Posts: 1563 Status: Offline

Sounds like a chronic case of the Viper Fart$. Wink

Not the same thing, but before the GE's shut down, they don't run 'em up as they do the pratts. When I first got to Hill and they started the jet up, I was witness to a bunch of smoke followed by a flame, never saw it before that time.

That can happen if the jet was "motored" but not started, and then didn't have time for it to evaporate before start.

Another Crap and Whitney problem eh?

I know what us ground crew thinks of the GE vs PW but I'd like to hear what the drivers have to say, but that's probbaly another thread for another day.

Yeah I have seen what shiz302 talking about happen all the time. I was told the reason is that green suiter moves the throttle over the horn before it's time. It dumps all that raw fuel in there. Big white cloud then bang a huge flame ball. It's really impressive, and even better at nite.

It must be a p/w thing. The KC135E our base used as a transport used to lightem up pretty regularly during the summer. If the jet didn't have enough time at a low power setting (while taxiing in) to cool the tailpipe it would often flame up about 3 - 5 minutes after shutdown. We had to connect the ground air cart and be ready to motor an engine to blow the fire out and cool things off if it happened.

The prettiest tailpipe fire I ever had was on engine start. I had just heard the throttle up call from the pilot and was looking for the heat out the back to make the "ignition" call when I saw the white fog instead. Just then I heard the nav say "the ignition breaker was popped, I'm reseting it". Before I could yell NOOOOO, he pushed it in, and it blew flames 30 feet out the back of the engine. The pilot cut the throttle and kept the starter engaged and somehow avoided overtemping it.

Enthusiast Joined: Jan 26, 2006 Posts: 75 Status: Offline

shiz302 wrote:

I know what us ground crew thinks of the GE vs PW but I'd like to hear what the drivers have to say, but that's probbaly another thread for another day.

I'm a big fan of the GE. I've flown the 220 and not the 229 so its not really a fair comparison to the GE-129. The two motors create thrust differently. PW makes more heat to create more thrust while the GE uses more air. Just two different ideas. The GE definately has more power but the reponse time is slightly delayed comparted to Pratt. With the 220 I would get nearly instant thrust while the GE spools up and then gives it to ya(sts). Both are very reliable motors but the GE has a few features the Pratt doesn't. GE has more than just PRI and SEC, it also has Hybrid modes for minor issues. Its been a while since I've flown the Pratt but I'm pretty sure the GE has some additional stall protection features that PW lacks. The 229 would be a much better comparison to the GE-129 but I don't know much about that motor, sorry. In closing, the PW-220 sucks and blows but doesn't give you a whole lot of bang.

Elite 2K Joined: May 13, 2004 Posts: 2945 Location: Utah

Yep... I have seen it too, not often but it does get your attention when she "lites up" after shutdown, all that old residual fuel. It was a problem for awhile, I dont know if it still is? Been off the active ling for years now.....

when you shut down the piece of iron, something leaks out of the bird at the enginebottom. is this spare kerosine?

(omg I feel like a total noob I am sorry!)

Elite 2K Joined: May 13, 2004 Posts: 2945 Location: Utah

Fuel that is dumped but normally it is recycled back into the aircraft now, least it was before I got out of the USAF. I had not seen fuel dumping on the ground after shutdown in quite some time now. I don't think it happens anymore, gets recycled (if this is what your asking)?

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