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On some turboprops, such as Jetstreams, the props are spun by hand through a dozen or so rotations after shutdown to move some air through and get rid of anything left in there so that doesn't happen.

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I've seen it happen to Pratts only, when I was at Luke in '04 this still occured. It's why you need a bucket for shutdown.

it always happens on our RNLAF f-16s they use a bucket with sand in it for that.
thats why you always see fuel marks on the floors in hangars and shelters, some CC forget Wink

GE engines at least the F110-100 fireball on start especially if it cold, for whatever reason. Once the engine is warm-say an interface run or the test cell, that sucker usually won't fireball or fog fuel.

Is that what happened to the Thunderbird at Langley this year during their engine runup? It sounded like they were running the jfs for a long time and then started up. The one plane had a big cloud of white mist coming out the exhaust nozzle for quite some time and then (of course when I put my camera down) something ignited the fuel that was dripping below the stabilizers. The mist did not ignite.

Seen the auto igniton on a Pratt JT-9 during start. The pilot put the fuel to it before he got 20 percent N2 and it flamed for about 10 sec. It was cool because the had a tail wind and the wind was blowing the flames back over the engine. They just kept motoring it and it lit off without a problem. HaHa I was on the fire bottle and I was totally zoned out by the fact a flame was coming out the back of the jet. I remember thinking "look at that....hmmm, thats gotta be a hot start huh"? Not exactly what I was supposed to be thinking as I was manning the bottle!

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I've worked on the GE-129 for six years now and never seen an auto ignite ever. To be honest, it does'nt happen on the GE's. You have to keep in mind that the T.O.s are the same for the GEs and Pratts but with minor changes. The only time u will see a fireball on a 129 is fi u take to long when u do a low energy ignition check or you are running a pickled (Preserved) motor for the first time, which is undersatndable because you are lighting off oil, not fuel. Or u happend to get a no light and you have excessive fuel in the a$$ end. And after shutoff, what u see in the exhaust is not fuel, it is oil from the drain under the mixing duct. To put it straight, the is no auto light after shutdown on a GE129. The books just has old info in it. Think about it. Why does the cockpit and book talk about a FTIT gauge? The GE has no such thing. Betcha did'nt know that the FTIT signal comes from the T5.6 which is a EGT, not a FTIT!

Mushmouth, the warning is there due to it happening once before. Just because YOU haven't seen it yourself, doesn't mean it hasn't or will not happen. Far as the FTIT gage, yea, we know, there's a thread about it on here. Maybe you could check your ego at the door next time.

No ego there Crewdawg. But I've already had that discussion there with the GE Reps about that issue. Thanx for the feedback though. Very Happy

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Tail pipe auto ignition