Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

B737 or Jet aircraft generally Tail-Pipe Fires

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

B737 or Jet aircraft generally Tail-Pipe Fires

Thread Tools
 
Search this Thread
 
Old 3rd Aug 2007, 13:14
  #1 (permalink)  
Thread Starter
 
Join Date: Jun 2000
Location: Australia
Posts: 4,188
Likes: 0
Received 14 Likes on 5 Posts
B737 or Jet aircraft generally Tail-Pipe Fires

The B737 QRH gives direction on procedure to combat a tail-pipe fire. Because the engine fire detection system does not cover the tail-pipe area, it is presumed the alert will come from outside sources. A Boeing source (have forgotten the details) indicates that components of the engine remain hot enough for up to 20 minutes after shut down to ignite residual fuel.

I wondered if Pprune readers can furnish details of their experience of tail-pipe fires and the circumstances. These would be useful for discussion points during simulator briefings as one very rarely hears of tail-pipe fire reports.
Centaurus is offline  
Old 3rd Aug 2007, 13:21
  #2 (permalink)  
 
Join Date: Mar 2006
Location: Choroni, sometimes
Posts: 1,974
Likes: 0
Received 0 Likes on 0 Posts
727, 300/310, 320, 340 never had a tailpipe fire. Only in the sim.

Fly safe
hetfield is offline  
Old 3rd Aug 2007, 19:06
  #3 (permalink)  
 
Join Date: Jan 2005
Location: uk
Posts: 1,266
Likes: 0
Received 0 Likes on 0 Posts
Have had a self-extinguishing tailpipe fire during a second start following IGN failure on a B737. After our first start attempt(s) with a failed igniter, we pulled back onto stand and got an engineer to inspect and ADD the failed igniter iaw the MEL.

Second pushback, engine start - all appeared absolutely normal in the flight deck. We received a cabin crew call (unusual - they wait until taxi before giving the cabin secure) - the no. 1 had had a call from the back that passengers had seen fire/flames in the engine, were concerned, and had contacted the rear crew, who informed the no. 1.

We asked the chap on the headset (Czech, but who spoke good English) if he had seen anything unusual during the start. "Yes there were flames but it's all OK now". Good job he was there to monitor the start, eh?! Anyway, fairly obvious that the 'fire' was just pooled fuel from the first failed start attempts and that nothing was wrong with the engine. Pax PA made along the lines of "you know what happens when you put too much lighter fluid on your BBQ..?" and all normal after that.
Gary Lager is offline  
Old 3rd Aug 2007, 22:31
  #4 (permalink)  
 
Join Date: Jan 2001
Location: UK
Posts: 2,044
Likes: 0
Received 0 Likes on 0 Posts
With a cynical hat on The best response to a G/C call of "tailpipe fire" is "what... errrr say again, errrr.... oh tailpipe fire" to which the reply will probably be "well there was, but it's gone out now" "OK - engines running - thanks very much"
NigelOnDraft is offline  
Old 4th Aug 2007, 04:29
  #5 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,571
Likes: 0
Received 0 Likes on 0 Posts
Scene, GQNN, two years ago.
L1011 on the parking stand, ready to start engines, but no APU, so external pneumatic air and electrics are used.
So far, so good.
Captain attempts to start the number three engine.
It winds up OK, but after starter cutout, runs down...reason unknown.
Captain does not close the HP fuel and ignition switch.
Tailpipe fire ensues.
Tailpipe fire drill not carried out...reason unknown.
Fire gets bigger...a lot bigger.
Ground Engineer, who is by the R2 door, notices the fire and races to the down galley, jumps out of the galley service door, and uses a large Halon extinguisher on fire...meanwhile, another ground engineer goes to the FD and suggests to the Captain that if he does not want the right hand wing to burn off, he had better damn well switch OFF the fuel and ignition switch.
Captain does so, just as the airport fires services arrive.
No outward damage is observed, and after a detailed engine/airplane inspection, the aircraft is dispatched to destination.
Said Captain has now retired to (I think) Spain, and it is just as well, as clearly proper tailpipe fire procedures were not followed, which is not at all satisfactory.
Gotta know the proper drills folks, otherwise big trouble can develop, darn quick.
411A is offline  
Old 4th Aug 2007, 11:57
  #6 (permalink)  
 
Join Date: Mar 2002
Location: Florida
Posts: 4,569
Likes: 0
Received 1 Like on 1 Post
Tailpipe fires are not hazardous as long as you have airflow through the engine, at least have the starter motor on. If that is not possible (PAX milling about the inlet after self evacuating) then cutting the fuel as quickly as possible will reduce the damage to the aircraft.

I don't recall an incident where a tailpipe fire alone, burned through an aircraft firewall although there have been several where the aft wing was severely damaged while on the ground.
lomapaseo is offline  
Old 6th Aug 2007, 07:08
  #7 (permalink)  
 
Join Date: Jan 2006
Location: australia
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts
Devil

running a 767 cf6 aircraft on eng ground run and tested fire handle due to replacement,forgot to close the fuel cutoff lever and then went for a restart.due to fuel cutoff lever being in the run position before 20% had raw fuel vaporising and streaming out the back. Once lightup occured the fire ball was sucked back around into the fan and up over the wing.
the ground observer was last seen running for his life still trying to tow the aircraft with him by the headset.scary but very comical.no damage done and egt within limits
chemical alli is offline  
Old 6th Aug 2007, 12:59
  #8 (permalink)  
Thread Starter
 
Join Date: Jun 2000
Location: Australia
Posts: 4,188
Likes: 0
Received 14 Likes on 5 Posts
To all contributors above. Thanks a million for your input. Intend to print them out and use them as excellent briefing material on the subject. I have seen "torching" during engine start of JT8D's in the 737-200. Alarming sight at night but flames quickly disperse. I am not quite sure it could be classed as a tail-pipe fire though. Don't think so.
Centaurus is offline  
Old 7th Aug 2007, 20:32
  #9 (permalink)  
 
Join Date: Feb 2005
Location: flyover country USA
Age: 82
Posts: 4,579
Likes: 0
Received 0 Likes on 0 Posts
I had the misfortune to have a test cell operator panic during a startup - the engine had preservative oil in it, thus a delayed lightoff and tailpipe fire. He terminated the start then re-engaged the starter - with the result being a sheared tower shaft between the gearbox and core engine. (That's an interesting problem to sort out, BTW - the apparent core rotation on the instruments is simply the starter turning the gearbox, but the engine is disconnected )

Anyway, no harm done with the low-energy fire in the tailpipe, but we had to fit a new tower shaft...
barit1 is offline  
Old 8th Aug 2007, 20:40
  #10 (permalink)  
 
Join Date: Nov 2002
Location: Only upon request
Posts: 871
Likes: 0
Received 0 Likes on 0 Posts
tail wind factor

I was a dispatcher 2 years ago and while providing a headset departure, a tail pipe fire occured during a V2500-powered A319 engine start. Wind was strong and its direction opposite to engine flow. Impressive experience...
FLEXJET is offline  
Old 9th Aug 2007, 17:42
  #11 (permalink)  
 
Join Date: Jul 2007
Location: UK
Posts: 186
Likes: 0
Received 0 Likes on 0 Posts
Have also seen the result from a 'crash engaged' starter motor, not pretty, wind and disengaged clutch pawl springs do not mix!

Have known guys whilst ground running to throttle the engine up slightly to blow out a tail pipe fire, as per their ground run manual.

I remember meeting an aircraft with no apu available, guy shutdown both engines simultaneously, a tail pipe fire occured and we had no way of blowing it out quickly, luckily found an extinguisher!
Beeline is offline  
Old 9th Aug 2007, 20:22
  #12 (permalink)  
 
Join Date: Mar 2006
Location: Ormond Beach
Age: 49
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
Let me give you guys one better. I fly the mighty CRJ, on which (as on many aircraft) the APU is deferrable. Let's imagine the following scenario: we land with a deferred APU, taxi in, shut down #1, then #2, whose tailpipe promptly catches fire. Now, we have a memory item for this situation and it is this:

AFFECTED ENGINE ---------- Dry motor until ITT < 150C or starter limit

Question: how in blazes am I supposed to dry-motor it, if the APU is deferred?
flyboyike is offline  
Old 9th Aug 2007, 21:57
  #13 (permalink)  
 
Join Date: Apr 2005
Location: uk
Posts: 260
Likes: 0
Received 0 Likes on 0 Posts
With an APU as a deferred defect, shouldn't you dispatch with a proviso that your destination(s) have been advised to provide you with ground power and air? Maybe not - but in my experience, we would not shut down the last engine until the previous engine had reduced below a certain N1 rpm. Ground air cart would then have taken over as 'motoring air'.
On a previous fleet- L1011 TriStar, with the early RR RB211's, tailpipe fires were not infrequent, and with spectacular visual displays!
skiesfull is offline  
Old 10th Aug 2007, 19:47
  #14 (permalink)  
 
Join Date: Apr 2005
Location: Stockholm Sweden
Age: 74
Posts: 569
Likes: 0
Received 0 Likes on 0 Posts
On a previous fleet- L1011 TriStar, with the early RR RB211's, tailpipe fires were not infrequent, and with spectacular visual displays

Yes when I was first on the L1011 around 1980, when the APU was inop we always closed the Nbr 3 engine last by pulling the fire handle. This ensured there was no fuel left when the engine stopped. The reason was that the HP Fuel valve was unreliable and the cause of the tail pipe fires. When the engine had stopped you closed the fuel/ignition switch and an engineer checked that it was closed. Then you reset the fire handle.
Swedish Steve is offline  
Old 10th Aug 2007, 20:22
  #15 (permalink)  
 
Join Date: Apr 2005
Location: Stockholm Sweden
Age: 74
Posts: 569
Likes: 0
Received 0 Likes on 0 Posts
I can remember two tail pipe fires in my time.
In BAH we used to do compressor washes on the B732 JT8 engines using a mix of demineralised water and 5% JetA1. One day, unknown to me the rig had been filled with nearly neat kerosene! On the post wash run the fuel in the jetpipe caught fire during the start, ran out and then ran back under the engine. Being quick thinking (in my youth) I let the engine run up to idle until the jet pipe fire went out, then shut the engine down and extinguished the flames under it with a fire extinguisher which we had with us.
The other one was a CX B742 on the ramp. For some reason the CX engineer wanted to test the ignitors during the transit. What you do is to trip the HPSOV CB, then open the fuel/ignition switch. He tripped the ignitor s CB instead. When he had walked down to the engine to listen to the ignitors, the fuel had ignited itself in the hot engine. We changed the engine for him.
Swedish Steve is offline  
Old 11th Aug 2007, 04:14
  #16 (permalink)  
 
Join Date: Oct 2001
Location: farrrr east
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
I experienced a tail pipe fire on a B737-300 aircraft several years ago after an MEC change, during first engine start, closed start valve and motored for 1 minute, then a second start was uneventful.
I noticed an orange glow from outside, as the headset man was a bit slow informing me of the event. Late afternoon, sun going down, snow around.
allthatglitters is offline  
Old 11th Aug 2007, 18:42
  #17 (permalink)  
 
Join Date: Jul 2007
Location: UK
Posts: 186
Likes: 0
Received 0 Likes on 0 Posts
Ground air carts are never in abundance at LHR unfortunatley!
Beeline is offline  
Old 12th Aug 2007, 10:55
  #18 (permalink)  
LEM
 
Join Date: May 2003
Location: The Roman Empire
Posts: 831
Likes: 0
Received 0 Likes on 0 Posts
The most difficult thing to do is the PA announcement after a tailpipe fire...
LEM is offline  
Old 12th Aug 2007, 11:45
  #19 (permalink)  
Thread Starter
 
Join Date: Jun 2000
Location: Australia
Posts: 4,188
Likes: 0
Received 14 Likes on 5 Posts
LEM. On an allied matter, what is the policy in your company regarding a warning announcement to the cabin crew and passengers in event of (say) an aborted take off due to something like a fire warning. After the aircraft is stopped does the captain first make a PA and then conduct the QRH Recalls - or do the Recalls come first (fire handles, firing the bottles etc) and only then is the PA made?
Centaurus is offline  
Old 12th Aug 2007, 12:33
  #20 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,571
Likes: 0
Received 0 Likes on 0 Posts
An interesting question, Centaurus.
Clearly recall parts of the drill are important, but so is having the punters calmed...and not heading for the exits, enmass.
And, this brings up another point.
If for some reason, all electric power (except for the hot ships battery bus) is lost due to engines being shut down in a hurry, do you still have a functioning PA system?
On modern aircraft of course, the answer is yes, but this was not true in some earlier jet transports, for example, the B707's that Braniff had purchased new.
Some of these found their way to other carriers, and this was not realised, until I pointed it out to a check Captain during a proficiency check in the companies sim.
He was sure he was correct, and I knew darn well he was not, so out on the tarmac we went, and tried the PA with all engines shut down, but with the battery switch ON, in an 'ole Braniff 707 that the company had...sure enough it didn't work, and he had to eat crow on the spot...this was of course after he had signed my check form as 'completed to a very good standard'.
411A is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.