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B737NG engine fire just below V1

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B737NG engine fire just below V1

Old 19th Jun 2007, 12:21
  #41 (permalink)  
 
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It confuses me when the what if arguments call for the reader to accept as fact some historical failure scenario, be it the Concorde, British Airtours, Pac West, etc. etc. and then incorrectly interpret the facts to support a pre concieved justification for their action.

If the thread is to stick to engine fires and go-no-go decisions, then perhaps we could rule out discussions relating to ruptured fuel tanks where no fire bell was sounded. Remember that the best protection that you have to prevent an inflight engine fire from disabling the aircraft is the fuel shutoff valve to the affected engine. I don't think that you can statistically cite many accidents where inflight engine fires, within the engine pod system progressed to the point where they prevented the aircraft from flying. Your greatest risk is when the aircraft stops on the runway (including landing)
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Old 19th Jun 2007, 20:13
  #42 (permalink)  
 
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Rainboe
If I was you I think I would have a talk with my sim instructors and tell them that I would like to try one or two of these tight circuits with ongoing engine fire at or after V1 next time in the sim.
I have done it in the sim and it works. Not much time to think but thats not what you want to do.
Memory items complete and fire still burning initiate the turn needed (as you have briefed in your t/o emer brief)
As parabellum said leave the flap config - this giving a tight circuit and fast landing config
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Old 21st Jun 2007, 11:32
  #43 (permalink)  
 
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Fat Dog,

Hey!, we agree. In the spirit of the thread (Fire Warning before V1), my reference to not knowing any aircraft that had any fire warning automatic inhibit, I was referring to the BEFORE V1 case. As you have quoted for the B757 -

"Warning Inhibits

The Master WARNING lights and fire bell are inhibited for fire during part of the
takeoff. The inhibit begins at rotation and continues until the first to occur:

400 feet AGL, or
20 seconds elapsed time

If a fire occurs during the inhibit, an EICAS warning message appears, but the fire bell and Master WARNING lights do not activate. If the warning condition still exists when the inhibit is removed, the fire bell and Master WARNING lights activate immediately."


This is common-place with most aircraft in the modern era for both Boeing and Airbus. My reference was with respect to inhibit below V1.

If you look at the philosophy that the two major manufacturers have used, we can see -

(1) Master Caution is inhibited at a quite low speed below V1, to prevent unnecessary rejects for "less than serious" unserviceabilities, AND

(2) Master Warning and Fire Bell is typically inhibited from V1/Vr through to approximately 400 feet or so, to prevent excessive crew reaction for a SHORT period (you've quoted 20 seconds) during the critical initial flight phase.

Putting these 2 inhibit conditions together, we are left with SERIOUS warnings, such as the fire bell, still completely active right up to V1 or rotation.

Why? Because in the infinite wisdom and experience of Boeing and Airbus, these SERIOUS warnings must not be inhibited at the pre-V1 flight phase so that the appropriate action may be taken by operating crews. And what is the appropriate action that Boeing and Airbus are trying to initiate? REJECT REJECT REJECT!

I think that your quote from Boeing said it all!

Regards,

Old Smokey
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Old 21st Jun 2007, 12:05
  #44 (permalink)  
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Firstly, for me too it is STOP below V1, no questions.

That out of the way, then, at V1/V1+ the problem is that we have 'grown up' to treat an engine fire in a calm, collected fashion, climbing on the OEI procedure, cleaning up and doing the drills/ c. crew brief etc, because we are taught that an engine fire is not 'life treatening'. Unlike some military a/c I have flown where an engine fire could burn through the flight controls PDQ, the emphasis is on measured response. The thought of someone not trained to actually FLY the aircraft at lowish levels in a hurried pattern gives me the shudders, and could well result in an overbank or CFIT, and in marginal weather............................

Is it indeed time, as hinted here, to swing sim training more to this scenario? Obvious problems with sim visuals etc, but maybe we could practice the old military type short pattern procedure, say at 1000'?

We'd certainly get throught the sim detail quicker
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Old 21st Jun 2007, 12:09
  #45 (permalink)  
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Is it indeed time, as hinted here, to swing sim training more to this scenario?

You can count Centaurus and JT in ... works well for confidence building and training exposure .. and might just save the day some time when a real quick circuit is seen to be the best option .. fire or whatever ...
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Old 21st Jun 2007, 13:30
  #46 (permalink)  
 
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An Eng or APU fire warning is really by design not inhibited in any phase for the A-320 Fam. aircrafts from what I know of. Believe that is also the case for the 330/340.

Last edited by manuel ortiz; 21st Jun 2007 at 18:19.
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Old 22nd Jun 2007, 09:28
  #47 (permalink)  

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We seem to be long on opinion here and short on good facts....

Adding to the former, I'd like to suppose that there is good reason for what seems to be a fairly industry-standard paradigm when dealing with engine failures once airborne.

To my mind, the supporting evidence for the evolved methodology ought to be in the public domain, accessible to each and every one of us professional pilots.

This evidence is the litmus test that justifies/underpins the manufacturer's SOP.

It's also going to be extremely helpful to me if I'm ever in the dock.



I'd like to see more discussion on V1 spreads. I'd hazard a guess a high percentage of runways most pilots operate from (except those which are field length limited - and even then you may not be limited by the single engine no-go case) have V1 spreads, and that, a high percentage of time, one is not operating up against the limiting case.

It is an added layer of complexity but its extra time available for your decision-making.

I'm quite happy to concede the contrary, especially if the evidence warrants the case, but of course, evidence of successful RTO's in excess of V1 is always likely to be hushed up isn't it?

In fact I can't recall any I've read about....

More training would always be something I'd vote for.

The 80/260 reversal, OEI, low level, FD off (obviously) is something I've tried and like BOAC says, it makes you shudder!

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Old 22nd Jun 2007, 09:47
  #48 (permalink)  
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Any fire warning is a major Mayday emergency. If the mechanical warning is backed up by calls from the cabin that there is a bright orange glow outside, even after firing all your shots, you have a major Mayday-plus-plus problem. The solution is put it down NOW. Not a nice circuit and complete OEI drill, but now- any runway, large empty road. I know an 80 degree course reversal, at low level, one one engine, is a highly dangerous (and difficult) manoeuvre, especially when you are trying to line up again, or a low level OEI circuit is similarly extremely risky (I didn't discount the danger- my post said <<Maybe an 80 degree low altitude course reversal/land back on reciprocal, on one engine might be pushing one's luck a bit, but I think there is a case for training>> I do recall there have been cases of both low and high pressure Fuel Shut-off valves (which are both in the strut/engine casing) being destroyed, though I can't recall exact instances. At such a time, you would literally have just a few minutes at most only.

Does the panel think we should, when the circumstance demands, be far more 'get on ground soon as poss' minded and perhaps practice such procedures as one engine low level circuits or low level 80 degree course reversals at the end of sims, despite the risk they inherantly are?
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Old 22nd Jun 2007, 13:03
  #49 (permalink)  
 
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So, you have an engine fire, do you do the classic, or do you leave flap alone, 80 degree course reversal, and land reciprocal as soon as poss? We are all coming round to the thought now that with a fire, every minute you save could save you.
One of the sequences in the simulator (737) was a simulated severe cabin fire ar VR and a close-in low level circuit - the object being to land back on the duty runway into wind with minimum delay. Times varied with pilot handling skill and were generally between two and three minutes from lift off, tight left hand circuit and stop. Best times were one minute and fifty seconds.

While considered a "fun" exercise simply because it wasn't in any syllabus we were aware of, nevertheless there was a deadly serious side to it.

We tried the dumbell 80/260 turn to land on the reciprocal of the departure runway but the tailwind component and loss of sight of the runway environment during a large part of the manoeuvre made for a difficult exercise. A tight left hand low level circuit to land into wind as per take off, proved to be the safest (?) method.

I understand that El Airline now incorporates this manoeuvre as part of command upgrade training. In the El Al 737-800, the best time via low level left circuit was one minute and thirty seven seconds from lift off to stop.
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Old 22nd Jun 2007, 14:36
  #50 (permalink)  
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The problem with making too much of a 'crocodile' circuit (make it snappy) is that if you cock it up and go-round..........................far better to space it out a little and get it right first time. All these 'dramatists' quoting a 1:37 circuit !!TO STOPPING!!! need a chill pill - in my opinion, of course. Bear in mind that a 360 around the airfield at rate 1 takes 2 minutes, so what bank angle are we diddling with boys? Far more likely to cause a smoking hole than the UNLIKELY event of an uncontained fire causing UNLIKELY fatal structural damage.
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Old 22nd Jun 2007, 15:23
  #51 (permalink)  
 
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Originally Posted by Old Smokey
The fire bell is never inhibited automatically on any aircraft that I know of. It can be inhibited by the crew, but other visual warnings remain.
Originally Posted by Fat Dog
Actually Old Smokey not quite true.
B757 Operations Manual:
'Warning Inhibits
The Master WARNING lights and fire bell are inhibited for fire during part of the takeoff. The inhibit begins at rotation and continues until the first to occur:
400 feet AGL, or
20 seconds elapsed time
If a fire occurs during the inhibit, an EICAS warning message appears, but the fire bell and Master WARNING lights do not activate. If the warning condition still exists when the inhibit is removed, the fire bell and Master WARNING lights activate immediately.'
Actually Smokey, it has been 'done' in the latest variant of the DC9, understand that you have some time in the '9'

Boeing 717-200 FCOM Volume III

"Takeoff Inhibits - Level 3 alerts and associated MASTER WARNING lights are inhibited from V1 to 400' RA, but no longer than 25 seconds in flight."

If a FIRE L ENG, FIRE R ENG, or APU FIRE is detected at V1 to 400' RA, the Engine Alerting Display will show a boxed red alert, but no fire bell will sound nor will the red MASTER WARNING illuminate until after 400' RA/25s.
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Old 22nd Jun 2007, 15:38
  #52 (permalink)  
 
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Agree with BOAC. Tried the quick circuit and the turnback manoeuvre in the 757 as a "fun" exercise at the end of a sim. It can be done but it's not particularly controlled and very very easy to cock up.

Although not quite the same, I know of 2 hawk fatal accidents in the early 90s where the pilots elected to turn back, misshandled it and crashed. One was for an oil pressure caption, one for a fire warning. In both cases, the accident report concluded that a normal circuit would probably have been the best course of action.
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Old 23rd Jun 2007, 10:25
  #53 (permalink)  
 
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Given that we only do bi annual sim assessments there is only so much that can be covered and while you may get to have a go at a turnback/short pattern circuit you certainly won't get to be practised at it.

If things really are that dire (uncontained fire) then I'll give it a go based on the thought that if I don't I will die anyway. Nothing to lose. Certainly in my company people do often mention a return to reciprical in extremis and have thought through how to achieve this. How you fly the pattern will depend heavily on the weather conditions at the time.

For me its establishing the severity of the situation that is the key and that will then dictate my actions. Has the fire gone out or has the fire wire just burnt through? How do you know ? In the case of the Nimrods the flight deck had the huge advantage of well trained rear end crew on intercom who rehearsed such scenarios so the flow of info was excellant and enabled quick sound decisions to be made by the flight deck. In the commercial world crew are not trained to respond in that way and the flight deck often do not include them in the loop at an early enough stage to make a difference. We can't see the engines/wing/cabin they can so their discription of what is happening could be key.

I fully support a crew flying a turnback or short pattern in extremis but it is a risky mvr that could in itself lead to tragedy so before its initiated its important to establish that its needed.
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Old 23rd Jun 2007, 11:01
  #54 (permalink)  
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I did qualify the question thus:
If the mechanical warning is backed up by calls from the cabin that there is a bright orange glow outside, even after firing all your shots, you have a major Mayday....
so it is confirmed you are not having a good day. My query is really this: 'are we too programmed to only look at the traditional circuit/carry out emerg. drill/make PA/fly circuit/carry out app. chks/set up radios/land 10 minutes later rather than think, when you have a confirmed hand warming fire burning, to land within 3 minutes or you're toast?' I'm not suggesting it should be trained and such very hazardous procedure be thought of as an option unless you are burning and unable to handle the problem itself, but I wonder whether we should just occasionally practice a traumatic take-off emergency and aim to get it on the ground rapidly rather than go through drills? One thinks of the Swissair/Saudi Tristar stories where possibly they were not minded enough to get wheels in contact with terra-firma immediately.
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Old 23rd Jun 2007, 11:26
  #55 (permalink)  
 
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Fortune favors the bold,dont they say?Course reversal at 500' but make sure of the speed before going beyond 15 deg bank.Recall items,a Vref and the GPWS override can be done in the reversal procedure.
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Old 23rd Jun 2007, 11:36
  #56 (permalink)  
 
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My concern here is establishing in time what needs to be done. People do not routinely consult the crew at an early enough stage to make a difference. We have lots to do proceduraly and its often several minutes before contact is made with the cabin. The cabin may initiate contact, and will do if its a cabin fire, but they may not. Do we need to train to make more use of the crew and do they need to train for this kind of scenario.
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Old 23rd Jun 2007, 12:30
  #57 (permalink)  
 
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My 10 pence
I've also tried the 80/260 turn in the sim..with everything lit up flaps 15 and no left Hydraulic system thanks to an uncontained no 1 engine failure and subsequent fire.
It was done with a 800ft base and 2k vis. (a learning non jeopardy exercise)
I found the actual flying the easy bit, 45-50' AOB and watch the IVSI!!! it was all thought about in the brief..and best of all we both understood the maneuver.
Its a tricky thing to do, but not half as much bother as some appear to think...
BTW I add the caveat that I've done about 400hrs below 75 AGL survey flying, although not in a 757

V1 means go......below V1 means stop
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Old 23rd Jun 2007, 12:34
  #58 (permalink)  
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Do you think doing it on one, at night, with all hell breaking loose, is maybe pushing your luck too far?
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Old 23rd Jun 2007, 12:43
  #59 (permalink)  
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Personally I think doing it at all is pushing most peoples' luck too far from some of the handling skills I have seen.

Someone mention night? Are you saying you will not die at night with an 'uncontained fire'? If it needs doing, it needs doing night or day, vis and cloudbase permitting. We do, of course, climb to circling altitude, dont we, since we will be out of sight of the runway? Don't forget, then, to keep it inside 1.7nm for Terps.

You probably guess I'm not really in favour........................
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Old 23rd Jun 2007, 13:05
  #60 (permalink)  
 
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Hi ITCZ,

Actually, it would surprise me if the B717 did not have an aural fire warning inhibit after V1 (or Vr for non-FMC inserted V speeds aircraft via Air Ground sensing), all aircraft that I know of in the modern era do have such inhibits, NONE that I know of have a before V1 aural fire warning inhibit. On post #44 in this thread I responded to FatDog that I was referring entirely to the pre-V1 case, as that is what this thread is about.

I'm not going into print here to defend myself, but to illustrate again that all manufacturers in the modern era DO NOT inhibit the aural fire warning prior to V1, for the very good reason that it is prejudicial to the safety of flight to continue takeoff with an active fire alert, and it is intended that a rejected takeoff is the appropriate action. (If I must, I will TRY to find the reference from Boeing).

Yes, I did fly the Diesel 9, it had no inhibitions at all, nor did I at the age at which I flew it!

I have to ask here - Just what is it that pilots fear so much from a high speed (near V1) rejected takeoff? I'm well aware that a continued takeoff in MOST circumstances is statistically far more attractive, and most operator's policies reflect this. I strongly agree also with being "GO" minded, but with an engine fire? That one, along with control jam and a few other nasties are definately prejudicial to the safety of flight. The aircraft IS certified to safely accomplish a safe RTO prior to V1 (at least in modern aircraft), albeit with lower performance based safety margins than for a continued takeoff, AS LONG AS THE AIRCRAFT IS NOT ON FIRE!

Have we taken being GO minded a little too far, where brakes release is now the commit point?

Regards,

Old Smokey

Last edited by Old Smokey; 23rd Jun 2007 at 13:15.
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