Would you abort after V1?
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This has been a spirited thread.
Procedural points to keep in mind ..
(a) several folk have complained about some of ssg's posts. Be aware that I am following along behind and I alter/delete posts which I think are a bit out of line .. not just ssg's .. any ...
(b) so long as the posts are not too far out of order and the subject remains reasonably on flying matters the thread can remain here to stir up objective passions
(c) if individuals get to the stage where they feel that the thread is going in circles or whatever, there always remains the option to ignore it .. when enough lose interest it will, like near all threads ... sink into the abyss.
As a moderator, it is not my personal task to be the arbiter of what content should or should not be in threads .. only that they reasonably follow PPRuNe requirements.
The only "rule" we have here is that outright rudeness etc., will be modified or deleted as we consider appropriate
Procedural points to keep in mind ..
(a) several folk have complained about some of ssg's posts. Be aware that I am following along behind and I alter/delete posts which I think are a bit out of line .. not just ssg's .. any ...
(b) so long as the posts are not too far out of order and the subject remains reasonably on flying matters the thread can remain here to stir up objective passions
(c) if individuals get to the stage where they feel that the thread is going in circles or whatever, there always remains the option to ignore it .. when enough lose interest it will, like near all threads ... sink into the abyss.
As a moderator, it is not my personal task to be the arbiter of what content should or should not be in threads .. only that they reasonably follow PPRuNe requirements.
The only "rule" we have here is that outright rudeness etc., will be modified or deleted as we consider appropriate
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Post V1
Just a few thoughts:
1. I worked on a 767 which RTOed after no engine failure but failed to get airborne after Vr and sitting on the tail skid. Good thing they went for the RTO option as the airline calculated the various V speeds and put the wrong mass in for the take-off. (I seem to remember it was ZFW they put in when it was going off on a 10 hour jaunt but the pilots did fly short sectors at low masses in it too).
2. A 747 where the incorrect flex power was set and failed to get airborne
3. Please remember that more airports have full length 300 metre runway end safety areas than used to and some have delethalised (eugh!) the run off areas (size dependent on runway length)
4. The DC-10 multiple tyre failure scenario was made much worse by the (then) tyre design standard (or should it have been tire?) which only required the other tyres to carry 1.5 times the rated load. With the DC10 beam deflections, the opposite corner used to carry 1.97 x load which then blew it. Then you were in deep trouble, made worse by the wheel rims fracturing and shattering with subsequent spreading of the bits around at high speed (to cut hydraulic lines and penetrate fuel tanks). Then you have nothing for the brakes to bite into as there were no tyres left. Also the DC10 would not reach Vr when this happened so you were in trouble. Oh, and the brake pack wear could be minimum on all wheels so that you did not have enough energy absorbtion available to stop in time. A change in tyre load standards, wheel rim design standards, brake pack wear requirements and trying to get the V1 as close to Vr as possible helped stop the DC10s from falling off the end of the runways as often as they used to.
5. Not sure if the locked wheel non-rotation when taking off on an icy runway scenario still exists that did for the odd DC8 on departure. The wheels slid without rotating and the subsequent extra drag stopped the aircraft from reaching Vr. I seem to remember it was Anchorage, it was full of US Marines or similar so the evacuation was relatively successful based on fit males all willing to listen to commands etc.
6. If you have to stop, think about flaps which are generating lift and consider (coffee break only time, not when it is happening) raising them. The spoilers should kill the lift but I am working on one with no spoiler deployment. You probably don't have time to even think about the action when doing it for real, but it is worth talking through!
7. Remember to press the brake pedals as if you life depends on it. It does. Many pilots used not to press them hard enough. NASA simulator studies (ok, old data here) showed lots of pilots at the 70% pressure level. I hope that this has been trained out in many cases now.
8. If you RTO off the end and the nosegear collapses, many big jets will lose the PA from the cockpit. Makes the evacuate call a bit difficult to hear.
I hope that you never have cause to find any of this falling into "useful practical advice" classifications in your worlds. Unfortunately, I do in mine on a daily basis.
1. I worked on a 767 which RTOed after no engine failure but failed to get airborne after Vr and sitting on the tail skid. Good thing they went for the RTO option as the airline calculated the various V speeds and put the wrong mass in for the take-off. (I seem to remember it was ZFW they put in when it was going off on a 10 hour jaunt but the pilots did fly short sectors at low masses in it too).
2. A 747 where the incorrect flex power was set and failed to get airborne
3. Please remember that more airports have full length 300 metre runway end safety areas than used to and some have delethalised (eugh!) the run off areas (size dependent on runway length)
4. The DC-10 multiple tyre failure scenario was made much worse by the (then) tyre design standard (or should it have been tire?) which only required the other tyres to carry 1.5 times the rated load. With the DC10 beam deflections, the opposite corner used to carry 1.97 x load which then blew it. Then you were in deep trouble, made worse by the wheel rims fracturing and shattering with subsequent spreading of the bits around at high speed (to cut hydraulic lines and penetrate fuel tanks). Then you have nothing for the brakes to bite into as there were no tyres left. Also the DC10 would not reach Vr when this happened so you were in trouble. Oh, and the brake pack wear could be minimum on all wheels so that you did not have enough energy absorbtion available to stop in time. A change in tyre load standards, wheel rim design standards, brake pack wear requirements and trying to get the V1 as close to Vr as possible helped stop the DC10s from falling off the end of the runways as often as they used to.
5. Not sure if the locked wheel non-rotation when taking off on an icy runway scenario still exists that did for the odd DC8 on departure. The wheels slid without rotating and the subsequent extra drag stopped the aircraft from reaching Vr. I seem to remember it was Anchorage, it was full of US Marines or similar so the evacuation was relatively successful based on fit males all willing to listen to commands etc.
6. If you have to stop, think about flaps which are generating lift and consider (coffee break only time, not when it is happening) raising them. The spoilers should kill the lift but I am working on one with no spoiler deployment. You probably don't have time to even think about the action when doing it for real, but it is worth talking through!
7. Remember to press the brake pedals as if you life depends on it. It does. Many pilots used not to press them hard enough. NASA simulator studies (ok, old data here) showed lots of pilots at the 70% pressure level. I hope that this has been trained out in many cases now.
8. If you RTO off the end and the nosegear collapses, many big jets will lose the PA from the cockpit. Makes the evacuate call a bit difficult to hear.
I hope that you never have cause to find any of this falling into "useful practical advice" classifications in your worlds. Unfortunately, I do in mine on a daily basis.
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Doesnt JAR OPS assume engine failure at Vef, followed by a 2 second acceleration past V1 prior to executing and RTO, as part of accreditation?
Personally think that this is one of those areas where you on the day have to make the call, only however if you understand if its the wrong call and you have gone against SOP, you are going to get crucified.
Personally think that this is one of those areas where you on the day have to make the call, only however if you understand if its the wrong call and you have gone against SOP, you are going to get crucified.
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There will always be an accidents where someone who should have flown, rejected, and there will always be accidents where people who should have rejected, flown.
I just wonder, if more people died trying to fly a bad aircraft then reject into the grass at the end.
The accident statistics tend to say 'go' given all the bad reject accidents, but if someone tallied up the deaths from either way, I suspect the deaths from skidding off the end, are much less then flying to the scene of the accident.
I just wonder, if more people died trying to fly a bad aircraft then reject into the grass at the end.
The accident statistics tend to say 'go' given all the bad reject accidents, but if someone tallied up the deaths from either way, I suspect the deaths from skidding off the end, are much less then flying to the scene of the accident.
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Angels 60, whereas you're the same poster who was recently banned as ssg and Trickle 451, now back under a different name, where are you headed with this?
When one continues the takeoff after V1, one doesn't fly to the scene of the accident, one flies to safety; that's the point of continuing after V1.
Same agenda for you, or do you intend to keep backpeddaling?
When one continues the takeoff after V1, one doesn't fly to the scene of the accident, one flies to safety; that's the point of continuing after V1.
Same agenda for you, or do you intend to keep backpeddaling?
As I recall in the early 70's there was a Northeast Trident 1E that abandoned after V1 on RWY 28 in Bilbao. There was a large hill at the end of the RWY and in the Captains opinion the a/c had stopped accelerating (big split between V1 and Vr). The result was an excursion off the side of the RWY, one main gear collapsed and no-one hurt.
Initially the captain was held at fault until investigation complete when he was completely exonerated as it was found that deep puddles on the RWY which were not notified to the crew made it a contaminated RWY and the a/c was unlikely to have ever reached Vr.
With speed trend arrows that we now have I have on occasion seen the acceleration cease momentarily during a T/O and if this was substantially below V1 at Max Wt it would certainly make me think (usually more thrust is available).
Initially the captain was held at fault until investigation complete when he was completely exonerated as it was found that deep puddles on the RWY which were not notified to the crew made it a contaminated RWY and the a/c was unlikely to have ever reached Vr.
With speed trend arrows that we now have I have on occasion seen the acceleration cease momentarily during a T/O and if this was substantially below V1 at Max Wt it would certainly make me think (usually more thrust is available).
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Look at the facts, read the statistics and then make your own mind up!
The aviation authorities all agree, the manufacturers all agree.
see what the FAA think
The aviation authorities all agree, the manufacturers all agree.
see what the FAA think
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BusyB...Probably took a stong will to go against his company SOPs, social pressure, and the chance to get called on the carpet. Sounds like common horse sense and good situational awareness won out that day.
Fanatic-someone who won't change their mind and won't change the subject!
Chris: The VC-10 was one truly powered airplane if it could rotate and fly at SL with 2 out on a side. Vmca2 on the C-5 was fairly low, like the Vmcg, but flying off with 2 out would be hard to fathom except at very low weights, about 525,000 or less and favorable conditions. At that weight, Vmca2 would be close to V2.
Chris: The VC-10 was one truly powered airplane if it could rotate and fly at SL with 2 out on a side. Vmca2 on the C-5 was fairly low, like the Vmcg, but flying off with 2 out would be hard to fathom except at very low weights, about 525,000 or less and favorable conditions. At that weight, Vmca2 would be close to V2.
Look at the facts, read the statistics and then make your own mind up!
Those that want to argue their points will always selectively select any facts that support it without regard to historical statistics. The belief being that if you accept their arguments that it will change the future statistics.
Pilots who think
Discount ....+1 Today 11:55
Discount ....+1 Today 11:55
It sounds like he was detailing improper handling of RTO's and ---you can throw the best SOPs at any one but---if you can't correctly compute performance---then how that the fault of anyone---yes, you can force yourself to RTO after V1---but that's mostly pilot error--forgetting gust locks improper use of performance chart an improper configuration with the warning out---no one ever said there's Never a reason to RTO --and certain freak events [the DC-10 has had it's bad days
]---but it will most likely be YOUR fault---but what if there's a 200' drop at the DER? or a gas station a group of row houses?---excepting freak events you --GO!!! period----it would take some resolve to take that shaking aircraft into the air---that's why you need heart!!split second decision have saved lives--such as when a United 767????---held off on rotation because of an incursion----or when the pilot forgot the gust lock on a Challenger 600??? and aborted at past Vr and flew into a building and they all lived---and sometimes Fate is a Hunter!!!!
for the most part in 99.99% of cases you GO!---the other .001 cases perhaps could have been avoided and a few
that's life---- that's flying---live with it--- die with it or get out!!!
nuff said
PA
and no I'm not back pedaling I've said basically the same thing earlier
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With all due Respect
The wording of the question invites misunderstanding. Would you abort? Well, Yes, for obvious reasons, discussed here. The question implies discretion on the part of the Pilot. V1 means go, (Fly). It is a pre-decided V speed, and by definition, Removes (most) Pilot Discretion. Some Pilots, for reasons of inexperience or lack of understanding of English, will argue that V1 doesn't do what an experienced Pilot knows that it Does. If you like, whisper to yourself at Vef "Mother May I ?", then Launch, immature Ego intact.
Airfoil
V1, that speed at which I will continue the Takeoff Roll in every instance except those in which I cannot Fly, in which case I won't.
"I cannot Fly" : that condition in which, in my belief, the A/C will not Fly (God I better be right), or, the A/C refuses to Fly, (much better).
Airfoil
V1, that speed at which I will continue the Takeoff Roll in every instance except those in which I cannot Fly, in which case I won't.
"I cannot Fly" : that condition in which, in my belief, the A/C will not Fly (God I better be right), or, the A/C refuses to Fly, (much better).
Last edited by airfoilmod; 22nd May 2008 at 22:54.
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Pardon my Trollfeeding lads, but someone's gotta do it! 
Have a read at: http://www.faa.gov/other_visit/aviat...off_safety.pdf
Interesting that Ssg would only use the accidents where continuing the flight leads to an accident and where aborting would lead to a successful outcome.
Nice that the FAA has said that in cases where one elects GO, an overwhelming majority of cases leads to a successful result, and does not get reported... so the reasoning that SSg use is... moot to say the least.
PK-KAR
There will always be an accidents where someone who should have flown, rejected, and there will always be accidents where people who should have rejected, flown.
Interesting that Ssg would only use the accidents where continuing the flight leads to an accident and where aborting would lead to a successful outcome.
Nice that the FAA has said that in cases where one elects GO, an overwhelming majority of cases leads to a successful result, and does not get reported... so the reasoning that SSg use is... moot to say the least.
PK-KAR
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Nightmare!!
SSG you would be the worst nightmare on the flightdeck in an emergency.
Move over fast fingers freddie, we now have Second Guessing Git or put simply the SSG factor. The time to start being dynamic and using lateral thinking and problem solving is not at V1.
Move over fast fingers freddie, we now have Second Guessing Git or put simply the SSG factor. The time to start being dynamic and using lateral thinking and problem solving is not at V1.
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Yes I would...if the plane didn't accelerate to VR, massive control failure..missle hit the wing...anything that I knew would keep the plane from flying up in the air, I would take my chances in the overun.
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Considering there is no useful information available at this time, and most parties involved in the upcoming investigation aren't even on scene yet, speculation is unprofessional, and inappropriate. One may rest assured that all the details will come out in good time.