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guest27
15th Jun 2007, 14:20
Engine fire just below V1, is it always correct to reject take off?

rubik101
15th Jun 2007, 14:40
No.
If the engine is producing thrust as normal and all other indications are normal, I would continue, shut the engine down at 500' and return to land on the full length of the runway.

lomapaseo
15th Jun 2007, 15:42
I had thought that the fire bell was inhibited with sufficient margin to allow for either a statistcally safe abort or a statistically safe continuation, without the additional burdens in complicated "what-if" decisions by the crew.

Old Smokey
16th Jun 2007, 05:40
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.

Engine fire warning right up to V1 is a class A1 reason to reject the takeoff. If you have an uncontrolled fire on the aircraft (and every fire has the potential to be uncontrolled), you have about 3 to 4 minutes to destruction.

Reject! (But not at or above V1)!

Regards,

Old Smokey

sudden Winds
16th Jun 2007, 06:41
Strictly speaking you must have initiated a takeoff rejection by V1. But now, if you have an engine fire just below V1 and you abort or reject, you´re doing exactly what you´re supposed to do, exactly what they teach us in the sim, and exactly what the judge will determine as legal.
All takeoffs are "go minded" which means one tends to let the airplane do what the airplane knows best.....fly ! but there are a whole bunch of possible scenarios where one can´t speculate with "oh well I am a few knots below V1, no matter what happens I´ll keep going" because that speed is based on the aircraft´s capability to stop against its capability to be controlled and to accelerate safely for flight. What if you´re taking off on a contaminated runway and V1 is really low, and of course the fire is a REAL fire, and the engine also quits...not the simulator fires, where you only get the bell but the engine performs perfectly... What if you´re departing with anti skid inop...and your V1 is even lower...you decide to continue a takeoff with very low speed, low weight, you might have controllability problems...and may not accelerate, could tail strike and lose control.
All I am trying to say is that you can´t deal in absolutes here. High speed failiures are the probably the most critical scenarios and you can´t just say "I will never reject a takeoff maneuver this many knots below V1 or beyond certain point at the rwy or whatever. Someone came up with a V speed called V1 and your course of action must keep in mind this value.
Regards,
SW.
PS: and yes, old smokey ´s very correct..if its a fire...and you don´t abort, you could have 3 o 4 minutes to destruction, if it was IMC and you had to fly an instrument approach eww..nasty..hope those freon bottles help...

Hey this is my post #100 !!!!!

guest27
16th Jun 2007, 07:42
How do you know if a warning fire at -10Kts V1 is a real fire?

Better to fight the fire at 500 ft or at the end of the Rwy?


Cheers

gas-chamber
16th Jun 2007, 08:10
Even if you had a shock-horror moment on hearing the bell (as most of us would) and actually reached V1 before rejecting, in my opinion that would be the safer option because as old Smokey says, in the air a fire could destroy the vitals in 3 or 4 minutes. Better to go off the end at 20 knots, grind to a halt, get the pax out with a few broken limbs than to be faced with a Concorde-type situation in the air. And really, how often are you really, really stopping distance limited in a B737 from V1? On 25% of all take-offs? Depends on where you operate I suppose. So then we get into the actual odds of running off the end if the reject is actually commenced bang on V1.
At V1 minus 5 or even 10 knots you do not have the luxury of assessing how serious the fire is. You have to assume the worst and do what most briefings state in one form or another - reject for any situation which could make the airplane unsafe in the air. Argue the legalities of what constitutes V1 from the safety of the courtroom, not from the grave.

Oxidant
16th Jun 2007, 08:23
So where are you going to stop second guessing the aircraft systems?
As old Smokey posted, if you get a fire warning prior to V1 ...Stop. That is what V1 is for! (+ all your perf. calcs.)
If, (the one in a million) it is false, then you are on the ground no harm done, rather than, "oh it may be false" & the wing falls off three mins after take off!
Or, what would you have done in the unfortunate Concorde accident?
ATC calls "Fire" crew initially had no warning & continue. Had they rejected the take off perhaps some/all would have survived?(remember they had second(s) to assimilate that call before VR ,& they were already past V1)
Where do you start becoming a medium & stop being a pilot?
Hindsight is a wonderful thing after all..........
EDIT..(Gas-chamber & self must have been drinking the same mind altering brew!)

JEP
16th Jun 2007, 11:19
Regarding the Concorde:
The warning from ATC came 10 secs after V1.

guest27
16th Jun 2007, 11:42
The Concorde accident had different causes, but your last posts are really interesting.

Why Rubik101 and many others believe is better to go? Do you want add something else?

Guest27

john_tullamarine
16th Jun 2007, 12:39
Caveat .. didn't fly the NG only the Classic so my comments have to be generic ..

This is one of those conundrums where you might very well be "damned if you do and damned if you don't" . The correct answer is determined retrospectively by the outcome on the day .... and the Judge at the Enquiry ... if the outcome was less than fortunate on the day ..

As with so many things we discuss in this sandpit ... it all depends.... Certification tends toward the black and white (as it must do ... to be achieveable and repeatable) while the real world is a murky mixture of all shade of greys ..

Things which concern me include ..

(a) the chart accel stop data is based on a fuel cut at Vef .. ie one winding down rapidly and the resulting speed overshoot being contingent upon that very significant thrust reduction

(b) fire warning leaves you with two engines and a significantly higher acceleration (and speed over run .. 5-15kt might be a reasonable ball park figure) while you are going through the reconfiguration from go to stop mode ... ie if the takeoff is seriously accel stop limiting you are absolutely guaranteeing an over run if you stop ...

(c) how far below V1 is "just below V1" when the event manifests itself ? .. considering the particular Certification Basis for the aircraft ...

(d) how long is it since the far end has been cleaned of rubber deposits ? what is the over run like ? what is the crosswind ?

(e) if the runway is not accel stop limiting and has a comfortable margin (bit rubbery until the margin is large) .. then stop

(f) if the runway is accel stop limiting and the over run is nasty .. I'd keep going on the basis that the historicals favour that option on a risk management basis

(g) let's not argue about reverse thrust .. in a real serious situation the maximum effort deceleration is sufficiently high (those who have felt the effect of nosewheel brakes on the 727 will understand what I mean) that the practical effect of reverse is comparatively small in the overall scheme of things.

Of course, we could come up with a few more considerations with a modicum of thought .. but, whichever way you look at it ... it's not a nice place to be.

you have about 3 to 4 minutes to destruction .. which is why some of us push students on endorsements with a contrived minimum time circuit exercise .. engine or cabin fire .. same sort of scenario and concerns ..

.. some days one really should have stayed in bed .. for instance I have a friend who has driven a wheelchair for many years ... having stood in for another colleague on a particular test flight ... same sort of consideration at play .. all one can reasonably do is operate conservatively .. load the dice reasonably to your benefit ... and hope that Lady Luck, on those occasions that she is irritated, visits other people instead of oneself ...

HotDog
16th Jun 2007, 12:54
How do you know if a warning fire at -10Kts V1 is a real fire?

Better to fight the fire at 500 ft or at the end of the Rwy?

Well I know where I would prefer to fight a fire especially with the help of the airport fire crew and that is not at 500 feet!

danishdynamite
16th Jun 2007, 14:45
"Before 80 kts we abort for any malfunction,
after 80 kts cancel master caution.
Between 80 kts and V1 we abort for severe malfunction, fire, failure or incapacitation."

That would be a part of my emergency briefing.
So basically,
Before V1 = stop
At or after V1 = go
V1 is also normally reffered to as take-off decision speed.

I Just Drive
16th Jun 2007, 17:27
My understanding is, start stopping at V1 and you go through the fence. (You need to have started stopping by V1). Continue the Take-Off at V1 - 10kts and you cross the fence by 20 feet. Not much, but you cross it. And that assumes total failure of the powerplant.

Of course, runway length is a factor. If you are Vr limited, stop. If you are otherwise limited with a V split, god speed. (Or not speed)

I (on a short runway) agree with coming around for a whole runway, fire brigade in force, low speed landing.

Plus, you have the whole circuit to plan your legal defense.

sudden Winds
16th Jun 2007, 17:53
you´re not going off the fence if you initiate actions right at V1. An enormous set of unfortunate things should take place for that to happen.
1) improperly executed maneuvers
2) figures not correct (last minute wt adjustments or excess baggage not declared)
3) unconsidered wind changes
4) a performance deterioration factor not kept in mind
5) excessively worn out brakes
etc.......

Besides keep in mind that for a certain weight, flap, temperature, and wind, V1 is the same in a 6000 ft rwy as in a 12000 ft rwy (except improved climb) so you´re in one scenario you´re not going to go off the fence, no matter what..and the other one you might if things (or you) don´t perform as expected. V1 is generally unrelated to rwy length.....generally.

ManaAdaSystem
16th Jun 2007, 19:09
1: The majority of overruns happen with two engines producing thrust.

2: Boeing (NG) recommends to abort for fire warnings prior to V1.

In general I would abort.

If runway limited, particular if on a contaminated runway, I would not. Yes, I know all calculations say I'm OK to stop at V1 anyway, but real world is real world, and theory is theory.

Ashling
16th Jun 2007, 19:52
Boeing want you have taken the 1st action to stop no later than V1

With a fire before V1 I will stop. Having lost a friend to an airborne fire I have no desire to take an unecessary risk. Structural failure may occur as early as 4-5 minutes if the fire is uncontained and spreads. I do not practise turnbacks (onto reciperical) mvrs in the sim but I do practise stopping from V1 or below. The sim conditions you to fly a pattern back to land you may not have the luxury of that time as has been tragicaly proven several times.

guest27
17th Jun 2007, 01:50
It seems that most of you prefer to split between theory or sim (RTO below V1) and real scenario (keep going below V1 if blah, blah, blah).

Personally I agree with John when says "This is one of those conundrums where you might very well be damned if you do and damned if you don't".

Do you think Boeing should spend some more words about that or the right choice is just related to the pilot's wisdom.

idg
17th Jun 2007, 04:33
I would definitely be stopping.....but...

Can anyone recall an engine fire in a pod mounted engine which resulted in structural failure when airborne in recent years? Granted a fuselage fire is something else.

And I'd like to discount the 737-200 and that's a specific installation.

SR71
17th Jun 2007, 05:04
Sudden Winds,

...makes a good point for me.

On most runways of significant length you can do an improved climb T/O.

The V1 spread may be anything up to 30kts.

On these runways you can reject long past a normal speeds V1 and be assured of a theoretical stop on the runway.

Playing with fire?

I endorse what John Tullamarine says though...the call on the day is going to depend on a number of issues and it may prove to be a day on which you wished you'd never got out of bed.

:\

BEagle
17th Jun 2007, 06:55
Please tell me which airlines those of you who won't abort for an engine fire warning at V1 fly for?

So that I can avoid them!

rubik101
17th Jun 2007, 10:48
Beagle, you won't be able to fly again then. All airlines follow the procedure that if the engine fire/failure occurs at V1 then the take-off will be continued. Find me an airline that doesn't teach that and I won't fly with them!

BEagle
17th Jun 2007, 11:04
All right then, before the V1 call.

It should always be possible to reject a take-off before V1 - that's what it means.

But it requires prompt performance from a practised crew; and the closer you get to V1, the more important this becomes.

But rarely is V1 so limiting that an abort precisely at V1 will not allow the aeroplane to be brought to a halt on the RW/stopway remaining.

I must have initiated hundreds of fires/failures at V1 over the years (in the simulator, I hasten to add). Rarely did anyone screw up an abort disastrously - but they did have the luxury of at least 9 x 3 hour simulator sessions per year. Something which I doubt airline beancounters would ever allow these days.

john_tullamarine
17th Jun 2007, 13:30
Putting the desirability of procedural standardisation to one side .. one of PPRuNe's values lies in providing a forum for discussion ... it still depends on the circumstances.

It should always be possible to reject a take-off before V1 - that's what it means.

Depends on the certification basis for the Type/Model .. in particular, two engines operating vice one.

Depends on the environmental circumstances .. runway surface contamination, over run environment, and how limiting is the accel stop case (the 2 second pad may not apply for many of our older aircraft)

The correct answer is that as long as you can take the first action to abandon the take-off by V1

No decision to consider here .. in a limiting case, once you have initiated the stop, particularly when the brakes come into play, there is no changing your mind ...

Overall, we go with standardisation for all the usual reasons .. but it is appropriate that we are aware that there are sets of antipathetic circumstances which are going to bring us unstuck if we follow the "standard" gameplan.

Centaurus
17th Jun 2007, 14:41
This is one of those conundrums where you might very well be "damned if you do and damned if you don't" . The correct answer is determined retrospectively by the outcome on the day .... and the Judge at the Enquiry ... if the outcome was less than fortunate on the day ..

A well considered, thought provoking, reply, JT. Nicely put.
Interesting statements noted that structural failure due fire damage could occur with 3-4 minutes. Maybe so, although others may have contrary opinions on the safe time left.
Yet, in the many Pprune posts on engine fires (theory of) observed over several years, the majority of correspondents felt there was no great hurry to close down the engine and firing the bottles. These opinions appear to be based on the theory that the engine will probably fall off the wing before causing fatal structural damage. Again all theory and precious few facts.
In the simulator we see time and again, pilots who delay actioning the fire bottles until at least a minute - and worst case two minutes, after the initial fire warning. "There is no urgency" is their mantra - the excuse being the aircraft must be got under control before the crew look around the cockpit to see what the red lights are all about.
If an engine has failed after V1, (whether simultaneously with a fire warning or not) I would have thought the pilot would have not only immediately had the aircraft under control but the crew would have taken action to shut down the engine and fire a bottle if appropriate. This is notwithstanding the oft mentioned minimum height of 400 ft being attained before the first action is started.
Complacency in handling an engine fire can be potentially dangerous. There is no authorative guide that explains how much time is available before structural failure occurs following an un-actioned engine fire.
That being the case, a crew cannot afford to take the risk that all will be well and the bottles can be actioned at pilots leisure. The 3-4 minutes of safe flight available mentioned in these posts, suggests that others think along similar lines?

Ashling
17th Jun 2007, 15:16
In my previous life we relied heavily on rear crew to tell us what was going on. In two cases the info they gave enabled the flight deck to make the decisions required to save all their lives. Nimrod with bomb bay fire at St Mawgan when they turned back to land on reciprical and Nimrod ditching in the Moray Firth after an uncontained fire started by an errant air valve/starter motor. In both cases it was later assessed that the aircraft had been very close to structural failure within minutes. Tragicaly in Afganistan the crew were unable to get on the ground before that structural failure occurred.

I accept that pod mounted engines are different as they should fall off but it does illustrate how deadly an uncontained airborne fire can be and how little time may be available to you. For all you know the fire may be due a fuel leak ala Concorde which will rapidly spread so best to stop in my view. Would I stop at V1/rotate on a long non FLL runway with 7000' left ?, in the sim no, in the aircraft with a fire warning then yes I would and take my bollocking.

As an aside I always make a point in the sim of getting the senior cabin crew to do a visual on any engine that indicates the fire has been extinguished as fire wires have been known to burn through and thus indicate all is well (ish) and previous indicates that info from the rear may well be crucial.

lomapaseo
17th Jun 2007, 15:48
The data is clear that far more accidents have occurred for aborting takeoffs between 100 kts and rotation then for continuing a takeoff after a fire warning. In tne analysis of engine fires (the cause of the firebell) there is little data that shows that the fire will progress beyond the engine pod itself for several minutes while airborne.

The greatest majority of serious engine fires which have disabled the aircraft, have been associated with ruptured fuel tanks and ground pool fires after the aircraft has been brought to a stop. So yes my arguments are based on statistics and not one-offs like a Concorde

In the case of the high workload decision making in a takeoff environment, the addition of a firebell ringing at the point where intent of go-no-go and rudder control are paramont is an additional pucker factor that may impact on the more paramont decsisions of the bolded above. Hence, I believe that some aircraft automatically inhibit the firebell in this time frame. (perhaps a check with your aircraft manual might confirm this).

idg
17th Jun 2007, 16:32
A fascinating discussion with some interesting views for and against. As stated before my money is on stopping but I still want data!

As a friend of mine often says "without data you've only got opinions".

I have looked and searched many places but there is no hard data that I can find of engine fires in podded engines causing quick structural failure. Similarly how many engines go 'bang' at V1 (or close to it)?

That said you'd look pretty stupid carrying an engine fire into the air when using a take-off alternate. Imagine flying for an hour with an uncontrollable fire....doesn't bear thinking about.

Which why I will still reject the TO when the fire bell rings. Trying to weigh up the alternatives near to V1 is not part of a sensible gameplan to my way of thinking.

el #
17th Jun 2007, 23:26
July 2004, a 757 bound to La Havana, is at take off.
9 Knts before V1, engine fire n. 2 goes alarm

Commander, decides to continue. Both fire bottles are discharged, however the fire alarm stays on (later they will lean that the extinguishers managed to put off the fire, but the alarm remained because damage to sensors wires).

Commander decides not to discharge fuel and land immediately.
Passengers are evacuated, the investigation will find that a ruptured fuel hose caused the fire.

Report just published, in Italian with many portions are in English and clear photos.
http://www.ansv.it/cgi-bin/ita/EI-CXO%20ansv.pdf

The pilot was commended and nobody questioned that he exercised his command authority is a sensible manner during all phases of the emergency.

pilot999
18th Jun 2007, 13:06
once saw a channel express F27 which had an engine fire just after take off, after take of, the fire was so severe they did a procedure turn to land on the opposite direction rwy, having seen the damage caused by a few minutes in the air, if they flew a full circuit to land on the correct rwy, I doubt the the crew would be flying today, the damage to the engine wing was pretty horrific.

john_tullamarine
18th Jun 2007, 13:34
At the risk of being controversial, it is important to note that the Industry's operations are based on risk assessment and risk management.

For the very great proportion of occasions and events within that set, the "standard" approach will work pretty well and is commended. We note that the standard procedure is not necessarily the best but is structured to provide a high probability of a successful outcome.

However, we must accept that, infrequently, circumstances are such that the usual procedure may be quite inappropriate .. should we vary our actions to suit ? do we have the capability even to detect the subtle differences from the norm ?.. is there even a sensible answer ?

Industry history has numerous examples of good outcomes and bad following out of left field unusual situations ... I suggest that it comes down to a mix of knowledge, skill ... and a very large helping of good or back luck .... which determines the ultimate outcome.

I think back to just two tragic cases where the crew apparently did all the "right" things ... but died with their passengers ... [Concorde at CDG and the DC10 at O'Hare]. Would the outcomes have been better had the Concorde been dumped unceremoniously back on the ground ? ... had the DC10 maintained the initial higher airspeed rather than pitch up to achieve V2 ? ... hard to say with any certainty at all.

United 232 .. I suspect Al Haynes et al would concede that Lady Luck played a part in keeping the toll as low as it was ....

While we push standardisation for a bunch of very good reasons, flying generally is not about guaranteed, black and white outcomes ... it is about risk and probabilities ... about loading the dice towards the desired, favourable outcome .... about constraining and controlling ill-disciplined operational behaviours ... etc ... etc....

Rainboe
18th Jun 2007, 22:40
Yes, but if you are below V1 and the fire bell goes, you're quite simply a dork if you take it airborne. No ifs, buts, whatever. To consciously take a potential fire airborne when you are already on the ground and freely able to stop, even on a limiting contaminated runway, show peculiar judgement. One needs to go into a darkened room and re-examine one's decision making processes. Period. There is no exception.

Next question please!

idg
18th Jun 2007, 23:37
El thanks for the link...interesting reading (well looking at photos cos my Italian is not good! :)) and Rainboe, yes I'm still in your court with the stop call. JT as ever good comments. Pilot, yes the F27 engine installation puts that a/c at much more risk of severe structural damage from an engine fire, but in podded installations is the question here.

I suppose what I'm really asking is are we still examining the correct basic failure with the traditional V1 cut and engine fire? Whilst I agree it's possibly the most serious incident we could face from a handling sense, the industry data tends to point to more human factors issues as being where we need to concentrate our focus to bring down the accident rate.
Oh yes...and having reasonable Smoke procedures that are simple and workable......don't get me on that one as it's my favourite hobby horse and I would be accused of thread creep again!

Rananim
19th Jun 2007, 09:54
There is no time to assimilate information whist on the takeoff roll so they make the decision rule-based.Its cut and dry.Below V1 you reject,at or above,you go.Its one of the few scenarios in aviation that is like this.Why do you think that poor Concorde pilot took his crippled aircraft to the skies?
As for ever taking a fire into the air below V1,well if you realized at high speed that the perf calculations were for another runway then you might push the thrust levers forward and elect to go at V1-10.The old eyeball method will tell you what is best.

Fat Dog
19th Jun 2007, 09:57
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.


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.'

Rainboe
19th Jun 2007, 10:00
What interests me, apart from this thread of whether to sto with a fire before V1, is what to do after V1 with a fire. Classic training is to handle the emergency, climb, clean up, Mayday, S/E procedures, circuit and emergency land. A good 10 minutes minimum with possibly an uncontrollable one burning. Thinking of BOAC 707 1967 LHR doing that and burning out, and Airtours MAN 737 about '88 that could have ended up airborne with a 6 inch column of fuel on fire pouring out of the wing, and many other incidents where fires don't give you that time. 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.

(Please! ONLY experienced large jet jockeys PURRLEASE! Or clearly state you are not if you have to interject).

danishdynamite
19th Jun 2007, 10:41
In case of ongoing fire in VMC stop climb in Acc Alt and depending on the airport layout make visual on fastest available rwy

IMC = radar vectors for fastest available ils again depending on airport layout e.g. crossing rwy

Everything prepared in fmc and setup wise and briefed in t/o emergency briefing

I-2021
19th Jun 2007, 11:02
Engine fire just below V1, is it always correct to reject take off?
Hi,

Boeing asks you to be so kind to stop takeoff below V1 for an engine fire. Is it a real fire ? You will discover it later on. If you stop take off above V1 then this is not correct. But you already know that a few knots before V1 you will probably end up by rejecting above that speed, especially if it is the fourth leg of the day by night. Next time you go in the sim try to reject within 5 - 6 knots from V1. Do it 10 times and try to get some statistics from that.:ok:

Bye.

parabellum
19th Jun 2007, 11:51
Rainboe - If I got a fire on the -400 after V1 I'd pull the gear up, leave the flaps where they are and thus keep the speed down for a tight circuit or course reversal, depending on airport. Minimum time in the air being the aim.

Rainboe
19th Jun 2007, 13:19
All sim training focuses on doing it properly, and in good time: climb straight ahead, handle the immediate emergency, continue, retract flaps no turning, then think about returning on one, with a very long downwind leg to fly. I agree an early return is needed, but I'm not sure you have that long. 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: 'get this sucker back on the ground as soon as possible- no! That's too long!'. In other words, a very rapid, immediate low level emergency circuit. Perhaps even briefing before take-off whether another cross runway is even quicker. But we are not trained to even think like that, and do it in the sim and you will be hammered. But I would far rather get back on terra-firma and hand it to beefy firemen than try and heroically deal with it in the air, then land.

lomapaseo
19th Jun 2007, 13:21
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)

danishdynamite
19th Jun 2007, 21:13
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

Old Smokey
21st Jun 2007, 12:32
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!:ok:

Regards,

Old Smokey

BOAC
21st Jun 2007, 13:05
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:)

john_tullamarine
21st Jun 2007, 13:09
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 ...

manuel ortiz
21st Jun 2007, 14:30
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.

SR71
22nd Jun 2007, 10:28
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.

:eek:

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!

:ok:

Rainboe
22nd Jun 2007, 10:47
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?

Centaurus
22nd Jun 2007, 14:03
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.

BOAC
22nd Jun 2007, 15:36
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? :eek:Far more likely to cause a smoking hole than the UNLIKELY event of an uncontained fire causing UNLIKELY fatal structural damage.

ITCZ
22nd Jun 2007, 16:23
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.
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.

Beakor
22nd Jun 2007, 16:38
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.

Ashling
23rd Jun 2007, 11:25
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.

Rainboe
23rd Jun 2007, 12:01
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.

Rananim
23rd Jun 2007, 12:26
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.

Ashling
23rd Jun 2007, 12:36
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.

haughtney1
23rd Jun 2007, 13:30
My 10 pence:ok:
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:ok:

V1 means go......below V1 means stop

Rainboe
23rd Jun 2007, 13:34
Do you think doing it on one, at night, with all hell breaking loose, is maybe pushing your luck too far?

BOAC
23rd Jun 2007, 13:43
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........................

Old Smokey
23rd Jun 2007, 14:05
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!:E

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

haughtney1
23rd Jun 2007, 14:12
Personally I think doing it at all is pushing most peoples' luck too far from some of the handling skills I have seen.

Kind of sums up my aviating credentials in one succinct phrase TYVM :}

BOAC
23rd Jun 2007, 14:20
At ease, Sir! I never flew with you:)

Ashling
23rd Jun 2007, 14:31
Choice of death or give it a go, give it a go.

Centaurus
23rd Jun 2007, 14:59
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.



And that is one of the problems. We spend countless simulator hours ticking the scheduled boxes, engine failures at V1 time after time, year after year, in addition to happily playing at actors and actresses during straight and level LOFT or whatever the latest terminology has it.

CDU buttons are pressed with great aplomb and the wonderfully reliable automatic pilot is used most of the simulator time. Yet hands on practice is rarely made available for the rare events that have really happened to other people. The events that require first class manual handling skills. For example let's include such things as close-in very low level circuits, dead stick landings, full blooded GPWS terrain warning and instant reaction pull-up, flight control failures where only the engines are left to give pitch and roll, the really nasty unusual attitudes and recovery technique, ditching technique in IMC - and other events I am sure readers can envisage.

rubik101
25th Jun 2007, 19:28
Rainboe's last post touched on a point I made some years ago which was not widely distributed in the pre-pprune era!
I entlitled my letter to the editor of Flight, Attitude at Impact. I am unsure if it was printed as I didn't and still don't subscribe to the magazine.
In brief, the point of the letter was that we pilots are programmed to behave in certain ways in certain conditions due to our SOPs and our sim rides every six months.
At the risk of a fatwa in my criticism of Captain Haynes and his crew, I mentioned the DC10 crash at Sioux City and questioned the decision of the crew to attempt to land the aircraft on the runway. They had proved to themselves that they had a very limited amount of control over the aircraft. What did they think when they decided to try to land on a runway, 8000 feet long and 145 feet wide? They had the whole of Iowa to land on, a flat and fairly hard landscape, I believe.
Bear in mind that when they were cleared to land, Cpt Haynes replied, 'You want to make it a runway, huh?' I think he was a little late in considering the option of landing elsewhere.
Their thought process was inbuilt over many years of flying experience. My contention is that this subconcious wish to land on or return to a runway is misguided. Our attitudes need to be altered to accept that there will be situations where landing straight ahead is a far safer option than trying any 35 degree turns on one engine with an uncontained fire, or no flight controls, come to that.
I know this thread is not strictly dealing with this issue but it seems like a good place to bring it up!
Slings and arrows this way!

EGPFlyer
25th Jun 2007, 21:36
If I'm gonna crash land then you can sure as hell bet that I'd rather do it at an airport where the Emergency Services are on hand within a minute or so as opposed to a field in the middle of Iowa where, if you're lucky, you would get farmer Joe and his trusty tractor on hand to give CPR and pee on your fire a week next Tuesday. ;)

rubik101
26th Jun 2007, 09:18
My point exactly. Try to land your uncontrollable aircraft and roll it on its side, tear it apart and burst into flames killing 110 passengers and 1 crew or gently lower it onto the mud and let it slide in one piece to a stop in the middle of the fields.

FlexibleResponse
26th Jun 2007, 13:00
guest27 has posed a very interesting question; namely.

Engine fire just below V1, is it always correct to reject take off?

A modern jet airliner is designed to withstand and contain an engine fire during any phase of flight. This includes from start to taxi, takeoff, cruise, descent and landing.

Considerer for a moment, what is the real world difference between an engine fire at 5 seconds before V1, 5 seconds after V1, during the climb, during the cruise (especially over the mid-Pacific where one might be 3 hours from any possible landing), or during descent etc?

The design engineers have to allow for the case of engine fire and in particular isolating the damaging effects of heat from critical structures for a period of time until the source of fire can be isolated, contained and extinguished. How can anyone say that a fire at V1 is somehow more time critical than a fire in mid-oceanic cruise?

Just going back one step, we all know that a fire can only exist with all three critical items being present; that is, a source of fuel, oxygen and heat. Without one of these elements, fire is impossible. Once an engine is secured, fuel, hydraulics, electrics have been cut off. Next, the extinguisher gases will deplete the oxygen.

Typically, engines that do catch fire continue to produce normal or at least significant thrust until they are secured. This thrust is usable depending on the situation (climbing to 400' agl for example) until the engine is secured.

At speeds close to V1, an aircraft has more potential to go flying than it has the ability to stopping. Indeed V1 for a particular situation may mark the last possible moment in time where the aircraft can be brought to a stop if all the prerequisite retardation devices work and the crew performs their duties precisely. Max/heavy weight takeoff aborts at V1 will always involve wheel fires and possible injuries to pax during any subsequent evacuation.

Your airline standard operating procedures will dictate what your actions should be in the case put forward by guest27. Nonetheless, if you are a Commander or aspiring to become a Commander, it is your personal responsibility to ponder the question that is on the table, in an unemotional and objective manner. Quite apart from the Coroner's Court, you may have to live with your decision for the rest of your life.

Engine fire just below V1, is it always correct to reject take off?

Rainboe
26th Jun 2007, 14:45
As the question stands....I'm a YES. I cannot think of any circumstance when I would not. Fire and humans don't mix. Fire and daralumin structures doesn't mix. What is your V1 for? You haven't got decision thinking time. It should be automatic:.....fire....below V1...stop.

guest27
26th Jun 2007, 15:23
Quite apart from the Coroner's Court, you may have to live with your decision for the rest of your life.......Flexible Response,
actually my concerns are exactly the brakes' efficiency in some specific scenario (fire always involved?) and the predictable pax evacuation in case of RTO procedure.

Many colleagues are contributing with their experiences but I still have some doubts if is better to reject always.
Thank you all,

Guest27

john_tullamarine
26th Jun 2007, 23:17
or gently lower it onto the mud

.. if we are talking about Sioux City ... if they had had anything like enough control over the beast to do anything predictable with it ... mud, runway, or whatever ... then they would likely have got away with no consequential damage and no injuries during the landing.

As it was, they had an aircraft which was extremely marginal in respect of any level of control ... Lady Luck helped a bit (except for the phugoid pitch down on short final) ... but full marks to the dogged determination of the crew on the day ..

danishdynamite
27th Jun 2007, 08:53
Taken from FAR PART 25 section 2 - abbreviations and symbols

V1 means the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance

Taken from FAR PART 25 section 107 - takeoff speeds

(a) V1 must be established in relation to VEF as follows:

(1) VEF is the calibrated airspeed at which the critical engine is assumed to fail. VEF must be selected by the applicant, but may noy be less than VmcG determined under Sec. 25.149(e)

(2) V1, in terms of calibrated airspeed, is the takeoff decision speed selected by the applicant, however, V1 may not be less then VEF plus the speed gained with the critical engine inoperative during the time interval between the instant at which the critical engine is failed, and the instant at which the pilot recognizes and reacts to the engine failure, as indicated by the pilot's application of the first retarding means during accelerate stop test.

_________

So for those of you who still want to continue before V1... :=

john_tullamarine
27th Jun 2007, 11:43
So for those of you who still want to continue before V1..

ah .. but one still has the little problem of lining up the black and white of the idealised and repeatable certification animal with the sometimes quite different real world beast.

As the aviation world is moving these days .. one needs an holistic risk minimisation approach to one's decision making .. most of the time the real world matches the ideal sufficiently (or with sufficient margin) that the decision is programmed and easy .. sometimes it is not quite so simple as overlaying the real with the ideal.

FlexibleResponse
27th Jun 2007, 14:04
john_tullamarine,

Very nicely put, Sir!

Best regards,
Flex

danishdynamite
27th Jun 2007, 15:09
I try again...

quote: V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance

No time to think - just act. Hence the repetitive practise in the sim...

Rainboe
27th Jun 2007, 16:37
ah .. but one still has the little problem of lining up the black and white of the idealised and repeatable certification animal with the sometimes quite different real world beast.

As the aviation world is moving these days .. one needs an holistic risk minimisation approach to one's decision making .. most of the time the real world matches the ideal sufficiently (or with sufficient margin) that the decision is programmed and easy .. sometimes it is not quite so simple as overlaying the real with the ideal.
Well it might be very nicely put, but what the hell does it mean? Is it Yes or is it No?

BOAC
27th Jun 2007, 17:45
It either means it is a definite maybe or he's been at the Fosters:)

lomapaseo
27th Jun 2007, 19:54
No time to think - just act. Hence the repetitive practise in the sim...

:ok:

Right on, unfortunately on the internet chats, pilots like to write about what they think should they be in a situation where they have no time to think.

I guess it's a macho thing

ManaAdaSystem
27th Jun 2007, 22:05
It's not black and white. Flying seldom is.

In most cases, it is a stop.

Now consider;

-1600-1800 meter runway.
-Runway is contaminated, mixed snow/ice.
-You use the reported braking coefficient.
-Computer has calculated your max take off weight down to the kilo.
-You are at max weight.

You know that;

-Braking action is measured at 60 km/h, not the required 90 km/h. It's not safe to drive faster.
-Braking action measurement is not an exact science.
-You use the average braking action of the far 2/3 of the runway.
-Conditions vary.

The fire alarm goes off at V1 minus 5. Both engines produce full thrust.

Do you stop?

Are you able to?

Now, as our Danish friend pointed out;

"V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance."

But he is talking about engine failure, not engine fire. An engine fire may be an engine failure, but it doesn't have to be. With 2 engines running you will have no problems (lifting off) if you continue.

If you continue on one engine, you will still lift off before the runway end. You will not clear it with the required 35 ft, but you will still be airborne.

I realise most of you never see this scenario, but some of us do. We can not afford to treat a situation like this like robots.

I don't feel very macho for saying so.

john_tullamarine
28th Jun 2007, 01:45
.. the last few posts represent where the discussion ought to be leading .. one of putting sensible and logically contrary viewpoints for the purpose of discussion and reflection.

Pilots need to have an idea of the real problems as opposed to SOP cant. Note I am not trying to belittle the SOP approach to things as such rigour, on the very great majority of occasions, provides us with a high probability of a successful outcome. The discussion ought not to be centred around what one might do on the day but, rather, examine the ins and outs of what should be considered in the decision making process which goes into the pre-roll briefing etc.

Some thoughts ...

No time to think - just act. Hence the repetitive practise in the sim...

This approach works well most of the time. However, we need to accept the consideration that there will be situations where the highly automated, rule-based, reaction may just not provide a desirable outcome. As is often suggested, it is not about absolutes .. it is about probabilities and the need to load the dice as much as one can in one's own favour ...

In critical circumstances, where the ideal is blurred by the reality of the real ... precisely this desirable skilset may just be the thing which puts the aircraft into harm's way ?

but what the hell does it mean? Is it Yes or is it No?

It means, for this question, that there are three domains of interest ..

(a) low speed black and white .. the probability of a successful outcome is loaded to the SOP stop case .. he who keeps going would be looked upon with critical gaze. This continues to be the case approaching V1 if the field length clearly is non-limiting with a comfortable margin ..

(b) an ill-defined, very greyish, area approaching V1 in limiting circumstances .. each case needs to be assessed separately. What is the best decision ? .. hard to say as the boundary conditions which constrain the decision making process may vary considerably.

(c) high speed black and white (assuming there is no secondary consideration arising which precludes flight) .. similar to (a) but loaded to the GO case.

(a) and (c) generally are easily seen as being rule based and programmed

(b) ... ? it depends ...

or he's been at the Fosters

.. only if there's nothing else on offer ... Hunter and Guinness for this lad by preference ..

We can not afford to treat a situation like this like robots.

That's the point I am trying to get across ...

Reel Marine
28th Jun 2007, 02:07
You said just below V1, well I would continue.

I havent read most of the responses on this thread but will.

As for the current thinking on aborts/stops. The TO should be divided into 2 regimes, low speed and high speed. The deciding factor is 100 knots, this is now industry standard is being taught by Airbus and Boeing.

Most of the overuns have been with good engines operating and most fire warnings are for a BLEED LEAK which can be best handled in the air rather than off the runway.

For me, I dont abort unless its for an engine failure before V1.

danishdynamite
28th Jun 2007, 02:55
How can you be sure that your assumptions of the condition of the runway won't allow for a succesful aborted takeoff before V1?
Can you make that decision in 2 seconds?
Fire warning - one, two - did you continue or reject?

Do you then brief it in your take off emergency briefing or is it something you decide if it happens, that you will continue before V1?

How do you know how bad the fire is to the engine and that the engine is not severely damaged by the outburst of a fire and then producing no thrust?

What is your new decision speed if you don't want to use the one calculated for you by the fmc, V1-1kts V1-2kts V1-3kts V1-10 kts V1-20 kts?

Where does your SOP allow you to disregard calculated FMC speeds and use one made up in your head?

Ignition Override
28th Jun 2007, 05:22
Guest27, let's suppose that you decide to abort the takeoff near V1, as the book states you can.

If your V1 speed is 156 knots with reduced flaps and you clearly see the end of the runway as you are near this speed as you abort the takeoff, there is NO guarantee, even if done perfectly, that your plane will stop on the runway, no matter what book theory claims. Yesterday, our flaps 5, V1 was 156 with a V2 at 166 knots. By the way, a mechanic told us that this airline no longer changes brake shoes when you feel an irritating chatter coming to a stop at low taxi speeds and write it up. They merely bleed air from the lines, somewhere near the anti-skid valves. Thi$ certainly has no effect on the operation.... This is just one component. Some of our mechanics have been told by a supervisor to avoid unnecessary line checks, because they might find a problem. $$

The people who approve and design the FAR$ often have never flown a high-performance aircraft, or not for many years. They are quite safe behind their desks with a view of a busy boulevard in Washington, DC, just as safe as your company Dispatchers.

In the US, an abort assumes that we can Begin the maneuver by V1 and still stop, not finish it by V1. Because of an inherent contradiction in the FARs and the fact that certification test aborts are done by well-trained test pilots in a brand-new plane and on a perfectly dry runway, lots of people might die if you abort at V1.

The engines, whether tail-mounted or wing-, will not normally let a real fire go from the engine into the fuselage or wings.
Do you want to be willing to hurt/kill some children riding in the back :ouch:when there could be just a bleed valve etc leaking hot air and the plane will probably rotate and climb at V2+10 with no problem, or after a warning which results when an MEL Dispatch Deviation Guide (DDG) procedure was not done correctly (maybe a computer fault)? How many years have your mechanics been repairing your aircraft?

Maintenance 'out$ourcing'?

ITCZ
28th Jun 2007, 07:07
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), ....
....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.

Oops, missed post #44. My apologies for making a redundant post.

Side issue, but the inhibit in question applies to V1 in all cases, whether a "magenta" or "white", that is, FMC calculated, or pilot entered.

ManaAdaSystem
28th Jun 2007, 11:00
How can you be sure that your assumptions of the condition of the runway won't allow for a successful aborted takeoff before V1?
I can't, that's the whole point. I can't tell for sure if I'll stay on the runway or run off the end. I know for a fact that the odds are stacked against me.
Do you then brief it in your take off emergency briefing or is it something you decide if it happens, that you will continue before V1?
Yes, it will be in my briefing. V1 minus 5 and we go
How do you know how bad the fire is to the engine and that the engine is not severely damaged by the outburst of a fire and then producing no thrust?
To the first part, I don't know. The rest will show up on the engine instruments.
Where does your SOP allow you to disregard calculated FMC speeds and use one made up in your head?
My SOP allows me to deviate from any published procedures in the interest of safety. I have to justify it later. The fact is, I don't know if I can stop. I know I can continue (performance wise). If I GO and land safe, all is well. If I stop and stay on the runway, all is well. If I stop and run off the end, they still can't touch me since I've followed my SOP to the letter, but to me it's not the smartest or safest course of action (given the circumstances).

Rainboe
28th Jun 2007, 11:57
I know if I was sitting at the back as a passenger on a take-off from as limiting a contaminated runway as you like, if the choice is available to the pilot, I would like him to stop and take my chances with an over-run than struggle into the air on one with an active fire warning going. Period. You can produce all the scenarios you like about how difficult it is, but it has been factored into the calcs and if stopping at V1 is open to you and you're burning, you're a darn fool not to! The firewire is pretty foolproof and failsafe- if it is blowing the warning, you must assume there is a genuine problem.

Realistically, on a twin, your acceleration is bewildering. Speed is building up so fast that at a few knots below V1, you don't have thinking time. You must go into automatic and not take a shoot-from-the-hip decision trying to factor in runway state/length/wind/slope. It's just that sort of decision making process that gets you into big trouble! Then you must imagine sitting in a witness box at a Coroners Court explaining your decision to go against rules and regulations.

lomapaseo
28th Jun 2007, 13:37
The people who approve and design the FAR$ often have never flown a high-performance aircraft, or not for many years. They are quite safe behind their desks with a view of a busy boulevard in Washington, DC, just as safe as your company Dispatchers.


I don't see that the FARS have anything to do with this.

The decision is a pilot decision.

the go-no-go recommendations are based on statistics (100kts and greater) and not about V1, a pilots decision simply considers V1

chuks
30th Jun 2007, 18:37
The Dornier 328 does have an inhibit function on its fire warning tone. (It uses a tone generator rather than an actual bell.) You get the Master Warning and the Fire Warning lights but the tone doesn't sound until you have passed a certain time/height boundary. (I'm not currently flying the type so that I cannot tell you the exact values but there is probably a 328 pilot here who can say what they are.)

This particular set-up could trigger an abort with a warning below 80 knots but a go with a warning between 80 knots and V1 if it was not noticed as a fire warning, since part of the usual brief is something like ".... abort for any red warning below 80 knots, abort for fire, blocked runway or loss of control between 80 and V1..."

I would have thought that if you had briefed for an abort for a fire below V1 then you should follow the brief and abort. Otherwise wouldn't you simply want to nominate a different V1 to suit the circumstances? The ideal is that a chosen V1 should allow a safe abort, isn't it? If one briefs one way and then acts in another way, well, that sort of makes a nonsense of doing the brief in the first place. Think of the poor old FO who would have to think, "This is Captain X who will probably want to abort," or else, "This is Captain Y who will probably want to go," and then hope he guesses right on the day. You could call that bad CRM!