Engine Failure after V1
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Engine failure after V1
Hi guys,
If an A/C has a problem ie engine failure past V1 and plenty runway available(10000ft remaining),would it be safer to keep it on the ground rather than climb and make things more hairy with dealing with the emergency in the air?(ie heavy,nasty wx)..
Should this be discussed in the T/O brief if such an occasion occurs?
I agree that one should obey OPS by the books..but would such a lateral thinking be omissed ?
Thank you for your inputs?
M.85
If an A/C has a problem ie engine failure past V1 and plenty runway available(10000ft remaining),would it be safer to keep it on the ground rather than climb and make things more hairy with dealing with the emergency in the air?(ie heavy,nasty wx)..
Should this be discussed in the T/O brief if such an occasion occurs?
I agree that one should obey OPS by the books..but would such a lateral thinking be omissed ?
Thank you for your inputs?
M.85
Last edited by PPRuNe Pop; 16th Nov 2003 at 05:54.
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Not an easy matter to evaluate by the pilots. Consider -
(a) while a first approximation of distance can be made using simple analyses, the real world may be somewhat different due to variations in acceleration/deceleration. However, the case may be reasonable for a low weight, low V1 takeoff on a runway with plenty of spare distance.
(b) at high weights/OAT etc the planned takeoff may be brake energy limited .. in which case a post-V1 reject may have predictable rather than successful results.
(c) the practical difficulties for long-habituated line pilots to invoke a novel and unpractised technique. The experimental test pilot is trained to do this sort of thing .. while the line pilot is habituated to practised responses. This is not to suggest that the line pilot is inferior ... merely that real world training and habituation regimes make for some difficulties in making seat of the pants decisions at very short notice. I have seen some line pilots do this sort of thing in very impressive style .. and others who would be better served by remaining well within the trained envelope.
(d) there is a body of historical evidence which suggests that the outcome generally is more successful if the aircraft continues the launch. This gives the pilots more time to consider their options and, importantly, means that a landing can be planned using ALL the runway with emergency services in attendance.
Obviously there are cases where the reject might have been better .. but we have to approach these sorts of questions from the view of overall risk assessment and reasonable probabilities - to base one's decision-making processes on exceptions probably is not a successful life strategy for most of us.
(a) while a first approximation of distance can be made using simple analyses, the real world may be somewhat different due to variations in acceleration/deceleration. However, the case may be reasonable for a low weight, low V1 takeoff on a runway with plenty of spare distance.
(b) at high weights/OAT etc the planned takeoff may be brake energy limited .. in which case a post-V1 reject may have predictable rather than successful results.
(c) the practical difficulties for long-habituated line pilots to invoke a novel and unpractised technique. The experimental test pilot is trained to do this sort of thing .. while the line pilot is habituated to practised responses. This is not to suggest that the line pilot is inferior ... merely that real world training and habituation regimes make for some difficulties in making seat of the pants decisions at very short notice. I have seen some line pilots do this sort of thing in very impressive style .. and others who would be better served by remaining well within the trained envelope.
(d) there is a body of historical evidence which suggests that the outcome generally is more successful if the aircraft continues the launch. This gives the pilots more time to consider their options and, importantly, means that a landing can be planned using ALL the runway with emergency services in attendance.
Obviously there are cases where the reject might have been better .. but we have to approach these sorts of questions from the view of overall risk assessment and reasonable probabilities - to base one's decision-making processes on exceptions probably is not a successful life strategy for most of us.
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Has anyone considered what would have happened if the AF concorde which crashed in July 2000 had rejected the take off (even though post V1) instead of trying to pull her into the air while still short of V2?
I've not seen any discussion of the exact distance remaining and their chances of coming to a full stop, but I find it hard to avoid a gut feeling that perhaps there might have been a few survivors if they'd aborted. Hindsight is everything, but once it left the ground the outcome was guaranteed, surely...
I've not seen any discussion of the exact distance remaining and their chances of coming to a full stop, but I find it hard to avoid a gut feeling that perhaps there might have been a few survivors if they'd aborted. Hindsight is everything, but once it left the ground the outcome was guaranteed, surely...
I'm not a fan of lateral thinking when there is a book of knowlege to follow based on learned experience and designed parameters.
In fact to encourage such thinking is to encourage an increase in the major cause of accidents (now 75%)involving powerplants which is "Inappropriate Crew response" to a perceived engine failure.
I'll admit that the book of knowledge was chock full of ignorance coupled with inappropriate application in training syllabus, but some of this ignorance perpetuated the lateral thinking which got us into trouble to begin with.
We should be beyond this now since we have updated the book of knowledge in the FAA/JAA initiative under PSM+ICR referenced elsewhere in this section under a very similar thread topic.
In other words we need less lateral thinking and instead more updated book learning and training application.
With that said the inference of aborting beyond V1 should be in the far corner of a pilots inner physic and not to be briefed.
In fact to encourage such thinking is to encourage an increase in the major cause of accidents (now 75%)involving powerplants which is "Inappropriate Crew response" to a perceived engine failure.
I'll admit that the book of knowledge was chock full of ignorance coupled with inappropriate application in training syllabus, but some of this ignorance perpetuated the lateral thinking which got us into trouble to begin with.
We should be beyond this now since we have updated the book of knowledge in the FAA/JAA initiative under PSM+ICR referenced elsewhere in this section under a very similar thread topic.
In other words we need less lateral thinking and instead more updated book learning and training application.
With that said the inference of aborting beyond V1 should be in the far corner of a pilots inner physic and not to be briefed.
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I utterly believe in SOPS and thought through orthodoxy but I do have a real nagging feeling regarding the last three major turboprop engine fires on take off.
Two in Canada were 'go minded' and crashed fighting their way around the circuit/pattern - spar burnthrough.
The 'lateral thinker' (HS748 - Stansted, UK) stopped on the ten thousand foot runway after a post V1 decision.
I promise I'm not stirring it - just thinking aloud.
Regards
Rob Lloyd
Two in Canada were 'go minded' and crashed fighting their way around the circuit/pattern - spar burnthrough.
The 'lateral thinker' (HS748 - Stansted, UK) stopped on the ten thousand foot runway after a post V1 decision.
I promise I'm not stirring it - just thinking aloud.
Regards
Rob Lloyd
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Dear all,
Thank you for your comments ..its always good to get professional advice.
The question was asked in my latest interviewat Netjets.
I answered the lateral thinking,but the brief needed.
I believe one should obey to SOPS but coming from a small freight dog world flying somewhat light aircrafts,i often thought about the idea of aborting at or after v1 (V1 calculated merely by temp and weight on a chart)if major problem occurred..engine flame out..
Also,the safety minded airlines may forbid such practice and i dont blame them either.
I believe this thinking may have come from flying in a not well organised and trained company..flight training was in A/C and not simulator and single pilot..
I didnt want Netjets to think i wasnt SAFE but couldnt lie either,ive been trained in a certain way of thinking but not rejecting other more regular way to handle emergencies.
Safe Flying,
M.85
Thank you for your comments ..its always good to get professional advice.
The question was asked in my latest interviewat Netjets.
I answered the lateral thinking,but the brief needed.
I believe one should obey to SOPS but coming from a small freight dog world flying somewhat light aircrafts,i often thought about the idea of aborting at or after v1 (V1 calculated merely by temp and weight on a chart)if major problem occurred..engine flame out..
Also,the safety minded airlines may forbid such practice and i dont blame them either.
I believe this thinking may have come from flying in a not well organised and trained company..flight training was in A/C and not simulator and single pilot..
I didnt want Netjets to think i wasnt SAFE but couldnt lie either,ive been trained in a certain way of thinking but not rejecting other more regular way to handle emergencies.
Safe Flying,
M.85
PPRuNe Handmaiden
This very topic has been kicking around the crew room(s) of late.
The thing that concerns me with "lateral" thinking is that it isn't briefed. If you have a nice long runway and a smallish turboprop then by all means brief the PNF that stopping post V1 is an option or else confusion will reign. There has been discussion of a re-land after V1 and a engine/failure etc. The thing with that is now you are in "no man's land". As has been said, us line pilots aren't test pilots and there's no performance figures published on what we are about to attempt. I kicked around some figures the other day and the distance required to safely stop was quite long. Much longer than many of the crew think. I can see the point about the fire burn throughs and it's better for the wing to fall off when on the ground but that sort of problem doesn't happen *that* often.
What worries me is that some captains are now starting to think that it is better to chuck the aircraft back on the ground and "it'll be ok". Well, no, not really. At the risk of teaching the learned readers here to suck eggs, the aircraft is now going faster than the probably V ref, certainly not in a landing configuration and with a lot less runway than would have been available if a circuit had have been done.
Lateral and flexible thinking is fine so long as the crew are both in the loop and there's been some reasonable thought gone into it.
#I fly a smallish turboprop. I have yet to sample the delights of a jet.
The thing that concerns me with "lateral" thinking is that it isn't briefed. If you have a nice long runway and a smallish turboprop then by all means brief the PNF that stopping post V1 is an option or else confusion will reign. There has been discussion of a re-land after V1 and a engine/failure etc. The thing with that is now you are in "no man's land". As has been said, us line pilots aren't test pilots and there's no performance figures published on what we are about to attempt. I kicked around some figures the other day and the distance required to safely stop was quite long. Much longer than many of the crew think. I can see the point about the fire burn throughs and it's better for the wing to fall off when on the ground but that sort of problem doesn't happen *that* often.
What worries me is that some captains are now starting to think that it is better to chuck the aircraft back on the ground and "it'll be ok". Well, no, not really. At the risk of teaching the learned readers here to suck eggs, the aircraft is now going faster than the probably V ref, certainly not in a landing configuration and with a lot less runway than would have been available if a circuit had have been done.
Lateral and flexible thinking is fine so long as the crew are both in the loop and there's been some reasonable thought gone into it.
#I fly a smallish turboprop. I have yet to sample the delights of a jet.
Sorry dept chief pilot Pprune, but its back to stirring the dunnies for you.
Re HS 748 at Stanstead, I could not find any reference in the accident report to lateral thinking or conscious decision making in the Captains decision to land back. Whilst the pros and cons for doing so may debated at length when on the ground, in the air the crew call the situation as they see it, preferably compared against standard operating procedures and experience. If the 748 crew were so convinced that the aircraft was not capable of continued flight then the decision to land ahead was fine, but I suspect (IMHO) that the aural and visual cues of this event overtook a rational evaluation of the situation.
As has been stated previously, in all but very exceptional circumstances the safer option is to continue the take off after V1. In addition to training crews to follow well thought-out procedures, they should be given training in the awareness and assessment of distracting cues. These cues should include ambiguous engine displays, sound, vibration, and external light (fire) at night. A big bang at rotate is more than likely a tire burst and not the over reacting choice of ‘bomb’ (based on probability). The safest course of action with an engine failure/problem/unknown event at/after V1 is to fly the aircraft; at a safe height evaluate the situation and then decide what the most likely cause of the problem is and then act on that judgment.
I would be concerned if M.85’s question was interpreted as flight with an engine failure was ‘more hairy’; many pilots do not have an appreciation of the safety margins that exist for non normal flight. Provided the aircraft is operated in accordance with the manufactures procedures, the certification standard provides for a very safe operation; this assumes that crews do not over react and “start thinking laterally”. Lateral thinking should be reserved for those extremely rare events (once in two lifetimes?) where there is no procedure: cf Capt Al Haynes DC-10 accident.
Please read the PSM+ICR project report: - ICR is Inappropriate Crew Response i.e. not following procedures. I quote for accidents for turbofan aircraft … “over 70% occur during the takeoff and climb phase of flight”. “The dominant phase of flight for all turboprop propulsion system malfunctions is Takeoff –this accounts for half of the accidents”.
Re HS 748 at Stanstead, I could not find any reference in the accident report to lateral thinking or conscious decision making in the Captains decision to land back. Whilst the pros and cons for doing so may debated at length when on the ground, in the air the crew call the situation as they see it, preferably compared against standard operating procedures and experience. If the 748 crew were so convinced that the aircraft was not capable of continued flight then the decision to land ahead was fine, but I suspect (IMHO) that the aural and visual cues of this event overtook a rational evaluation of the situation.
As has been stated previously, in all but very exceptional circumstances the safer option is to continue the take off after V1. In addition to training crews to follow well thought-out procedures, they should be given training in the awareness and assessment of distracting cues. These cues should include ambiguous engine displays, sound, vibration, and external light (fire) at night. A big bang at rotate is more than likely a tire burst and not the over reacting choice of ‘bomb’ (based on probability). The safest course of action with an engine failure/problem/unknown event at/after V1 is to fly the aircraft; at a safe height evaluate the situation and then decide what the most likely cause of the problem is and then act on that judgment.
I would be concerned if M.85’s question was interpreted as flight with an engine failure was ‘more hairy’; many pilots do not have an appreciation of the safety margins that exist for non normal flight. Provided the aircraft is operated in accordance with the manufactures procedures, the certification standard provides for a very safe operation; this assumes that crews do not over react and “start thinking laterally”. Lateral thinking should be reserved for those extremely rare events (once in two lifetimes?) where there is no procedure: cf Capt Al Haynes DC-10 accident.
Please read the PSM+ICR project report: - ICR is Inappropriate Crew Response i.e. not following procedures. I quote for accidents for turbofan aircraft … “over 70% occur during the takeoff and climb phase of flight”. “The dominant phase of flight for all turboprop propulsion system malfunctions is Takeoff –this accounts for half of the accidents”.
Unless one has compelling reason to believe the SOPs are inappropriate for the situation or don't cover it, then my money is on SOPs. The historical evidence is that SOPs are more likely to lead to a more favourable outcome.
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zerouali- I suspect you might! 
I agree with Tinstaafl generally.
There is nothing, however, in any Ops Manual to say you may not operate in a manner outside SOPs. They might not cover the situation, or the captain may decide that they are not appropriate in the situation at that moment.
Put simply, the captain always may exercise his discretion and operate any way he likes. He would, however, need a very good reason, and be prepared to defend his decision later - be it on the carpet in the CP's office, hat on and with no tea or biccies, or in a court or coroner's inquest.
The incident @ STN with the HS 748 was one such situation. The skipper knew his aircraft, which (like almost all 748's) was a tired, knackered old thing which was unlikely to be able to stagger round a single-engine circuit. He also realised very rapidly that he did not have a simple engine fire - he had a catastrophic failure threatening the whole airframe.
He broke SOPs and saved the lives of all on board.
PS - Towers - as far as I remember, he didn't actually stop on the runway. He re-landed, which took it beyond the runway but still within the airfield perimeter, which collapsed the nosegear.
I agree with Tinstaafl generally.
There is nothing, however, in any Ops Manual to say you may not operate in a manner outside SOPs. They might not cover the situation, or the captain may decide that they are not appropriate in the situation at that moment.
Put simply, the captain always may exercise his discretion and operate any way he likes. He would, however, need a very good reason, and be prepared to defend his decision later - be it on the carpet in the CP's office, hat on and with no tea or biccies, or in a court or coroner's inquest.
The incident @ STN with the HS 748 was one such situation. The skipper knew his aircraft, which (like almost all 748's) was a tired, knackered old thing which was unlikely to be able to stagger round a single-engine circuit. He also realised very rapidly that he did not have a simple engine fire - he had a catastrophic failure threatening the whole airframe.
He broke SOPs and saved the lives of all on board.
PS - Towers - as far as I remember, he didn't actually stop on the runway. He re-landed, which took it beyond the runway but still within the airfield perimeter, which collapsed the nosegear.
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Many moons ago I remember sitting on the tarmac at Malaga watching a Spantax DC10 taking off. The nose wheel came up and the oleos of the main gear extended then suddenly the aircraft slammed back down on the ground and careened off the end of the runway, smashed into a small building and caught fire.
There were several fatalities and it is a sight one cannot forget even now.
Apparently they suffered a nose tyre burst but thought it was a catastrophic engine failure so elected to try and stay on the ground, had they got airborne they could have gone out to sea, dumped and returned to a possible nose wheel failure on a long, foam covered runway somewhere.
The Spanish authorities defended the abort decision on the grounds that the DC10 had a bad safety record!
There were several fatalities and it is a sight one cannot forget even now.
Apparently they suffered a nose tyre burst but thought it was a catastrophic engine failure so elected to try and stay on the ground, had they got airborne they could have gone out to sea, dumped and returned to a possible nose wheel failure on a long, foam covered runway somewhere.
The Spanish authorities defended the abort decision on the grounds that the DC10 had a bad safety record!
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Your recollections are correct Capt S - I know the skipper and he did land back on the runway. 20 + years experience on that type.
A stirring defence of orthodoxy above - remember I did place very careful caveats at the beginning of my post. Entirely worthwhile in my opinion just to get a bigger audience for the PSM+ICR report. Meanwhile Danny and I still await the publication of the immense Luftansa report which we were allowed to preview some 20 months ago.
Thing is, the nagging feeling still hasn't gone away. In the specific area of turbo-prop engine fires from generous runways it must be tremendously gratifying to follow orthodoxy and find your mainspar burns through on the circuit. Of course you can imediatiately slap me down with the history of false fire indications or rejects that became fatal over-runs if it helps you support catch all solutions for the industry.
Perhaps, just perhaps, in memory of those Canadian crews if nothing else, there are areas of orthodoxy that need to be challenged in an era of tremendous peer pressure, standardised training and company expectations.
As discussed in the auto-pilot thread Ops manual sections on flexibility in operations are easily overwhelmed by long term company culture.
I will, of course, bow to your list of civilian turbo props safely carrying a major engine fire around the circuit to an orthodox, professional and safe conclusion over what - the last ten years say? Is orthodoxy serving this particular section of the aviation community? Is generic, catch all perceived and received opinion for both turbo fans and turbo props effective in the light of the accident record in this specific area?
It troubles me that not a single response had directly addressed what happened to the two Canadian crews who experienced the airframe failing - no (that's too clinical and detached) - melting while actually practicing what you're preaching from the comfort of your computer chairs. I want you to reassure me that my magpie memory is entirely incorrect and I've filtered out a plethora of gloriously successful conclusions to similar events in recent years.
Where safety is concerned I am more than happy for you to slap me to the ground with data. A bit of hubris is good for all of our souls.
Yours, as ever, stirring the dunny,
Rob
A stirring defence of orthodoxy above - remember I did place very careful caveats at the beginning of my post. Entirely worthwhile in my opinion just to get a bigger audience for the PSM+ICR report. Meanwhile Danny and I still await the publication of the immense Luftansa report which we were allowed to preview some 20 months ago.
Thing is, the nagging feeling still hasn't gone away. In the specific area of turbo-prop engine fires from generous runways it must be tremendously gratifying to follow orthodoxy and find your mainspar burns through on the circuit. Of course you can imediatiately slap me down with the history of false fire indications or rejects that became fatal over-runs if it helps you support catch all solutions for the industry.
Perhaps, just perhaps, in memory of those Canadian crews if nothing else, there are areas of orthodoxy that need to be challenged in an era of tremendous peer pressure, standardised training and company expectations.
As discussed in the auto-pilot thread Ops manual sections on flexibility in operations are easily overwhelmed by long term company culture.
I will, of course, bow to your list of civilian turbo props safely carrying a major engine fire around the circuit to an orthodox, professional and safe conclusion over what - the last ten years say? Is orthodoxy serving this particular section of the aviation community? Is generic, catch all perceived and received opinion for both turbo fans and turbo props effective in the light of the accident record in this specific area?
It troubles me that not a single response had directly addressed what happened to the two Canadian crews who experienced the airframe failing - no (that's too clinical and detached) - melting while actually practicing what you're preaching from the comfort of your computer chairs. I want you to reassure me that my magpie memory is entirely incorrect and I've filtered out a plethora of gloriously successful conclusions to similar events in recent years.
Where safety is concerned I am more than happy for you to slap me to the ground with data. A bit of hubris is good for all of our souls.
Yours, as ever, stirring the dunny,
Rob
Last edited by PPRuNe Towers; 17th Nov 2003 at 19:31.
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It is totally incorrect to give the impression that tired old aircraft will not perform as designed and certificated. Consideration of reduced performance due to an ‘old aircraft’ should not clutter the decisions required after engine failure. There was nothing to show that the STN HS748 would not have flown as well as any other aircraft type with one engine inoperative. The condition of the aircraft engine / structure with that particular fire is open to debate; the Captain made a decision and kept to the plan. Fine; in his opinion at that time, and up there doing it, the circumstances appeared to warrant a landing straight ahead.
The aircraft did leave the paved surface which collapsed the nose leg. However with some very good cabin crew work both in pre fight briefing and during evacuation everyone escaped. But what if leaving the runway there had been damage to the exits or fuselage structure preventing or delaying evacuation … would the engine / wing fire have been brought under control in time? We would be having a different discussion now – think about it whilst you are with Pprune on the pan.
It is totally incorrect to give the impression that tired old aircraft will not perform as designed and certificated. Consideration of reduced performance due to an ‘old aircraft’ should not clutter the decisions required after engine failure. There was nothing to show that the STN HS748 would not have flown as well as any other aircraft type with one engine inoperative. The condition of the aircraft engine / structure with that particular fire is open to debate; the Captain made a decision and kept to the plan. Fine; in his opinion at that time, and up there doing it, the circumstances appeared to warrant a landing straight ahead.
The aircraft did leave the paved surface which collapsed the nose leg. However with some very good cabin crew work both in pre fight briefing and during evacuation everyone escaped. But what if leaving the runway there had been damage to the exits or fuselage structure preventing or delaying evacuation … would the engine / wing fire have been brought under control in time? We would be having a different discussion now – think about it whilst you are with Pprune on the pan.
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It is totally incorrect to give the impression that tired old aircraft will not perform as designed and certificated.
Believe me - in a corporate world dominated by bean counters they aren't exactly furthering their careers by insisting on this..........
Additionally, whether military of civil, any of us flying within a fleet of ostensibly identical aircraft for any length of time know two things. At any given time there is an aircraft on the fleet suffering glitches and problems at a rate far greater than the rest.
We also know that, performance wise, there is alway a 'dog' amongst them.
This, I know, makes uncomfortable reading. We gain great comfort in empirical data apparently bolstering our confidence with a magical application of science, statistics and the hard graft of good performance people.
But - have you flown the company dog this week? - It's real. They exist.
Regards
Rob
Last edited by PPRuNe Towers; 17th Nov 2003 at 23:21.
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Dear all,
Amazing this pprune site..I must say i am quite impressed with the level of knowledge and english vocabulary used in this thread...eventhough i do not understand all words..
Even if aborting after V1 for a major incident came to my mind,i dont think i would have the guts to land on the same runway after rotation was made...Having been called "big balls or nutter after landing in not catholic weather,i believe once in the air,you are commited to fly,except of course if both engines fail and dont let you
Keep up the info,its delicious.
Safe flying,
M.85
Amazing this pprune site..I must say i am quite impressed with the level of knowledge and english vocabulary used in this thread...eventhough i do not understand all words..
Even if aborting after V1 for a major incident came to my mind,i dont think i would have the guts to land on the same runway after rotation was made...Having been called "big balls or nutter after landing in not catholic weather,i believe once in the air,you are commited to fly,except of course if both engines fail and dont let you
Keep up the info,its delicious.
Safe flying,
M.85
Unless you are operating at precisely balanced field conditions, you will always have a range of V1s available to you. The minimum V1 will be determined by your capability to get airborne if you continue (Vgo), the maximum V1 by the capability to stop (Vstop). The problem is that we only brief a single V1, and it varies between companies, and even fleets within companies, whether a minimum V1 is SOP (often favoured as the "go" option is statistically safer) or what is often (incorrectly) referred to as a "balanced" V1, which is mid way between Vgo and Vstop (which gives a margin for error in both senses and reduces the problems of being Vmcg limited). It is feasible to stop above your nominal (briefed) V1 up to the maximum V1, but as you invariably do not know what that is this may not be a sound idea. If you are in a turboprop and have 10,000 ft of runway ahead of you at rotate, the practicality is that V1 max is probably above your unstick speed. However, if you do not have the performance figures to back this up...........!
Rob, on the way back from the dunny,
Consider which performance documents your team use for the different performance calculations and which manufacturer / service-provider provided them. For certificated performance (JAR-25), the performance information in the flight manual covering engine out take off, flight path etc, has several built in assumptions (net / gross) that look after most variations. Of course there was the annual air check which caught and rouge aircraft, but no so now days.
The operational performance (fuel flow, range, etc) normally originates from the manufacturer. A reputable manufacturer will incorporate an engine / airframe degradation factor for age, or they should state the assumptions that have been made; others or service providers (in ignorance) may publish no corrections. Of course operators can make their own adjustments to this data depending on experience, maintenance condition of the airframe, and operational technique.
With respect to the thread and the edification of others, the engine out takeoff calculation should always provide the published performance for the operating conditions. Therefore crews should not be distracted by unwarranted concerns as to whether the aircraft will fly / climb or not. More likely is that the crew will be greatly surprised by the apparent lack of performance with an engine out in limiting conditions when compared with every day operations. The limiting climb gradient, engine out (WAT), may only give 200 ft/min climb, far short of the 2000 ft/min skyrocket seen on a cold day with a light aircraft. So after V1 continue the take off but do not be surprised by the performance. If not convinced or just to top up experience, try a WAT limit engine out climb in the sim.
Consider which performance documents your team use for the different performance calculations and which manufacturer / service-provider provided them. For certificated performance (JAR-25), the performance information in the flight manual covering engine out take off, flight path etc, has several built in assumptions (net / gross) that look after most variations. Of course there was the annual air check which caught and rouge aircraft, but no so now days.
The operational performance (fuel flow, range, etc) normally originates from the manufacturer. A reputable manufacturer will incorporate an engine / airframe degradation factor for age, or they should state the assumptions that have been made; others or service providers (in ignorance) may publish no corrections. Of course operators can make their own adjustments to this data depending on experience, maintenance condition of the airframe, and operational technique.
With respect to the thread and the edification of others, the engine out takeoff calculation should always provide the published performance for the operating conditions. Therefore crews should not be distracted by unwarranted concerns as to whether the aircraft will fly / climb or not. More likely is that the crew will be greatly surprised by the apparent lack of performance with an engine out in limiting conditions when compared with every day operations. The limiting climb gradient, engine out (WAT), may only give 200 ft/min climb, far short of the 2000 ft/min skyrocket seen on a cold day with a light aircraft. So after V1 continue the take off but do not be surprised by the performance. If not convinced or just to top up experience, try a WAT limit engine out climb in the sim.
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Just to throw another log on the fire 
Like Towers, I also know the STN captain well and have spoken to him at some length about the incident. He told me that the opinion of the investigators was that with the intensity of this particular fire, the main spar would probably have burnt through half-way down the downwing leg with the loss of all on board. Old aircraft or brand new would probably have made very little difference.
So, the debate remains open, but in my book that guy was 100% right. Excellent job.
PS That does NOT make it right all the time, of course!
Like Towers, I also know the STN captain well and have spoken to him at some length about the incident. He told me that the opinion of the investigators was that with the intensity of this particular fire, the main spar would probably have burnt through half-way down the downwing leg with the loss of all on board. Old aircraft or brand new would probably have made very little difference.
So, the debate remains open, but in my book that guy was 100% right. Excellent job.
PS That does NOT make it right all the time, of course!
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I suspect that we are missing one very useful piece of information here, for those who regularly fly machines like twin turboprops out of megarunways.
V1, as has been shown above, is not a particularly useful datum. It purports to be the final stop/go speed (purists, yes, I know that's a gross oversimplification - please let it pass). We all know it's not.
What would be more useful is, for any given runway, at any given weight, temperature, inside leg measurement etc., the highest speed at which we can still abort and stop before we plough through the fence onto the golf course or sewage works.
Given almost any failure of my aircraft, I would far rather abort on the ground and call an engineer to stroll over than to have to try to sort anything out in the air. But if I've passed V1 with still 9,500 feet of runway ahead of me, and the FO is expecting me to go after he's called a failure, I'm a bit stuck, since SOPs tell me I really ought to lift off. Why?.
V1, as has been shown above, is not a particularly useful datum. It purports to be the final stop/go speed (purists, yes, I know that's a gross oversimplification - please let it pass). We all know it's not.
What would be more useful is, for any given runway, at any given weight, temperature, inside leg measurement etc., the highest speed at which we can still abort and stop before we plough through the fence onto the golf course or sewage works.
Given almost any failure of my aircraft, I would far rather abort on the ground and call an engineer to stroll over than to have to try to sort anything out in the air. But if I've passed V1 with still 9,500 feet of runway ahead of me, and the FO is expecting me to go after he's called a failure, I'm a bit stuck, since SOPs tell me I really ought to lift off. Why?.
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Captain S - the problem is that it will never be that simple!
All fine if you are still on terra firma. The trouble is that the aircraft will be airborne at speeds above V1 on these runways, and in various states of gear and height. I would suggest it is impossible to define, and it boils down to being the captain - and that is what they pay us for? You have to hope that 20/20 hindsight will prove you right for once!
All fine if you are still on terra firma. The trouble is that the aircraft will be airborne at speeds above V1 on these runways, and in various states of gear and height. I would suggest it is impossible to define, and it boils down to being the captain - and that is what they pay us for? You have to hope that 20/20 hindsight will prove you right for once!