Tailpipe Fire during engine startup
 

I am trying to find out wich can be the maximum length of the flame of a tailpipe fire during an engine startup.
Expecially looking for info on the CFM 56, as I am flying B737...

thanks for any help on this...

F

you must be joking.

Someone told me if you can light your cigarette off the lick of flame that may be too much:E

Hard to measure from the flight deck too.:)

Just ask the sart up crew to check if they can cook burgers in it:}

40 feet is not unknown with the L1011, if one does not pay attention to the normal start procedure....:}
Sure gets everyones attention on the ramp.:uhoh:

ok thanks, message understood... I was thinking the same but did't have much experience on that as I had it only once...
in fact it was night (so easy to see) but the technician coudn't see it.
It was observed just by a car wich was more or less behind the A/c..

wow JP...THAT was scary:uhoh:

Who cares about the length of the flame, the concern should be about the length of time the flame lasts. The "hot-start" in that youtube movie seemed to last a lonnnnnnggggggg time. :ooh:

I assume that was an engineering run, there doesn't appear to be any worried pax' faces peering out of the windows

Does FADEC eliminate the chance of hotstart?

You can sometimes get a fire similar to that in the video after an engine change. Engines that have been in storage often have their fuel systems filled with preserving fluid. On the first run of the engine, this fluid will burn with a flame as it is passed out through the fuel system.

Regards, JetMech

They should have started with the Thromister Valve in the "On-Ekoch" position.

It should do but if there is residual fuel in the tail pipe (eg:wet spin during maint) you still may get some flame out the back.

No it doesn't. I had plenty of hot-starts on the Avro RJ100 which has FADEC.

I concur - FADECs should stop it but they have been known not to, I was on a team dealing with a fix which was nicknamed the 'great balls of fire' problem, for obvious reasons. We had the fuel on/igniters on sequencing wrong, the result was described as 'disconcerting for the passengers':uhoh:


VnV

Woo Hoo - flame check satis

Looks more like an engine that hasn't been de inhibited as opposed to hot start.

Agree, just ask Delta who lost an MD11 that way

Check out the video and this document

http://fromtheflightdeck.com/Stories/turbofan/

Typically there has not been a concern for tailpipe fires where there is airflow through the engine. I suppose this is due to the general abscence of persons and vehicles behind an engine that has a rare tailpipe fire.

On the other hand for the even rarer case where a tailpipe fire exists with little to no airflow (standing still and the starter is disengaged) the flames will turn upward and cook the bottom of the wing. Several severe outcomes have occured

You don't want to be taxiing too close behind an a/c with rear mounted engines starting up on a cold day.

It can be hard on the paint job -- and not the best enviroment for a fuel vent:uhoh:

If the start is otherwise normal (N2 accelerating, EGT/ITT normal) then it's best to continue the start. If you abort for any reason, and re-engage the starter during coastdown, you can shear a drive shaft. :eek:

Again, a good FADEC system should have a miminum starter re-engage speed interlock to stop the silly boys at the front end from messing with things they shouldn't!!

Vnv

And the EICAS or whatever should shout at them for trying.:=

Well back in the days of the DC9 if white fog coming from the engine on startup a 50 ft flame was not uncommon. :cool:

Thought it was a problem on RB211s during shutdown due to fuel pooling while idling. Not generally a problem on newer generation engines.

27 years ago (omygod!) I was sitting in the upper deck of a brandnew ANA 747SR on the ramp at Haneda, while a dozen line mechs pored over the shiny new cockpit. All was relatively quiet - but then I heard this foghorn-like sound, and I wondered what in a 747 could those guys have actuated that sounded like that. :confused:

After discreetly looking the situation over, and finding nothing relevant, I happened to glance out a portside window - and at least 500 m. away, there was an ANA TriStar cranking up. You couldn't miss the cloud of fuel vapor behind #2 engine. As the vapor lessened, so did the foghorn. :ooh:

Be aware that years ago, passengers decided to evacuate an airplane because of excess fuel from an APU start, which was under the right wing.

Will your Flight Attendants TELL YOU anytime they see anything which is abnormal, even fairly minor, unusual sounds and fluid leaks? If they find the Captain easy to chat with, and the Captain seems open to any useful information, they might not think twice about it.

With less obvious, minor abnormalities, after they find out that the c0ckp1t crew appear cold, arrogant or insulting etc, they might keep quiet. This happened between a (Western?) DC-10 FO and Captain years ago landing in Mexico City, and it led to a tragedy.

Yes, it was Western. IIRC the PF was a training captain who had personal issues with the PNF. :rolleyes: