Would you abort after V1?
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That's crazy...a canned 'let's go' regardless of the circumstances..I wonder how many airliners tried to fly it off, only to crash somewhere down the road vs even the very worst of overruns where everyone walked away.Sorry guys, sometimes the plane doesn't want to fly, and I could sit here and come up with failure after failure in the sim, where flying it off, is a death sentence for you and the passengers.I think some of you need to get out of your airline sims and go to another sim facility: When you get there say 'sock it to me' then you will see what I am talking about. Smart pilots recognize if they have a flying aircraft or not, and don't just default to SOPS, checklists and canned responses to all scenarios..
Most of us here fly real airplanes. Perhaps you should stick to your microsoft simulator world.
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We'll keep you posted if that changes.
V1, or my job?
Well Guppy, I guess on your PC, after V1 the plane always flies.
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SSG version X (I've lost count) continues to blabber on about how many have said "go" and crashed. He has yet to provide any numbers of:
% of a Go after a failure after V1, where they ended up with fatalities.
% of a a stop after failure after V1, where they ended up with fatalities.
Until then, I will not stop laughing everytime I see SSG or his derivatives online here.
PK-KAR
% of a Go after a failure after V1, where they ended up with fatalities.
% of a a stop after failure after V1, where they ended up with fatalities.
Until then, I will not stop laughing everytime I see SSG or his derivatives online here.
PK-KAR
Thank you PK
That's the essence of the whole argument within this thread.
If you follow the SOPs you will save more passengers than if you don't.
If you are inclined to try and stop it ad-hoc, then please try this in a qualified sim and take the knuckle raps by the instructors pointer stick.
SSG version X (I've lost count) continues to blabber on about how many have said "go" and crashed. He has yet to provide any numbers of:
% of a Go after a failure after V1, where they ended up with fatalities.
% of a a stop after failure after V1, where they ended up with fatalities.
Until then, I will not stop laughing everytime I see SSG or his derivatives online here.
PK-KAR
% of a Go after a failure after V1, where they ended up with fatalities.
% of a a stop after failure after V1, where they ended up with fatalities.
Until then, I will not stop laughing everytime I see SSG or his derivatives online here.
PK-KAR
If you follow the SOPs you will save more passengers than if you don't.
If you are inclined to try and stop it ad-hoc, then please try this in a qualified sim and take the knuckle raps by the instructors pointer stick.
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It's not even an arguement over which will save more passengers. One choice is right, one isn't. If one "saves" passengers by making the wrong choice, one is lucky; one hasn't actually saved anything. One has been saved from one's own foolishness.
Barring something that prevents the airplane from going airborne, there's no reason to reject at high speed, and as most all of us agree, it's with good reason. It's not a matter of playing the odds or leveling risk, or weighing where the most survivors will occur. It's a matter of making the correct choice, and in most all cases, that's going airborne.
Barring something that prevents the airplane from going airborne, there's no reason to reject at high speed, and as most all of us agree, it's with good reason. It's not a matter of playing the odds or leveling risk, or weighing where the most survivors will occur. It's a matter of making the correct choice, and in most all cases, that's going airborne.
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I looked at some numbers today and would like explenation if possible
please.
In the performance A320 book I picked a sea level runway with zero slope,
3800 meters length and checked the Take off speeds
115/ 119/ 122 Are the V1,VR, V2 flex 68 for 54000 kg take off weight.
149/ 149/ 152 flex 68 are the speeds for 63000 kg take off weight.
Now If I abort at 116 V1 for the 54000 kg weight, the plane will over
run the runway? but if I abort at 148 speed and weight 63000 kgs
The plane will stop before the end of the runway, although I would have
used more runway in the second case as the flex is the same.
This really does not make sense, as I had less speed, less weight
and more runway for the 54000 kg take off.
Any explanation please.
please.
In the performance A320 book I picked a sea level runway with zero slope,
3800 meters length and checked the Take off speeds
115/ 119/ 122 Are the V1,VR, V2 flex 68 for 54000 kg take off weight.
149/ 149/ 152 flex 68 are the speeds for 63000 kg take off weight.
Now If I abort at 116 V1 for the 54000 kg weight, the plane will over
run the runway? but if I abort at 148 speed and weight 63000 kgs
The plane will stop before the end of the runway, although I would have
used more runway in the second case as the flex is the same.
This really does not make sense, as I had less speed, less weight
and more runway for the 54000 kg take off.
Any explanation please.
tarik123
Whilst this thread has been concentrated on safe stopping, what those V1 figures actually mean are:
At 54000kg at 115Kt the aircraft will accelerate and take off in the remaining runway even if you lose an engine.
At 63000kg you need to be at 149Kt for that to be true.
At 54000kg at 115Kt the aircraft will accelerate and take off in the remaining runway even if you lose an engine.
At 63000kg you need to be at 149Kt for that to be true.
My Question is very simple speed 115, less weight and more runway ahead
is more critical than 144 speed more weight and less runway, this really
does not make sense
is more critical than 144 speed more weight and less runway, this really
does not make sense
Any graphics available to make sense out of this?
tarik123
And the answer is equally simple as I stated above.
There is a fundamental difference between "good-to-go minus one engine" and "committed to take off".
Strictly speaking V1 is the first one. However as the aircraft weight goes up or the runway length comes down the two parameters converge.
Yes, at 54000kg and 116Kt you may have the luxury of a second or three to decide whether your problem was really so bad that the aircraft wont fly and still stop with runway to spare. At 63000kg and 149kt you almost certainly would not.
It is the deadly grey area inbetween that has been exercising the contributors to this thread.
There is a fundamental difference between "good-to-go minus one engine" and "committed to take off".
Strictly speaking V1 is the first one. However as the aircraft weight goes up or the runway length comes down the two parameters converge.
Yes, at 54000kg and 116Kt you may have the luxury of a second or three to decide whether your problem was really so bad that the aircraft wont fly and still stop with runway to spare. At 63000kg and 149kt you almost certainly would not.
It is the deadly grey area inbetween that has been exercising the contributors to this thread.
Beau_Peep
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who cares about stats...
I would not care what the statistics and the number says..
I would go by the SOP rather than creating new definition of V1 at the most critical time of my life...
Personally, my strategy is : as I sense entering the high speed area (>100kts), I keep telling my self " This would be a 'go' "
by the way, does anyone know how many times the engines of airliners have failed above 100kts or closer to actual V1...
cheers
I would go by the SOP rather than creating new definition of V1 at the most critical time of my life...
Personally, my strategy is : as I sense entering the high speed area (>100kts), I keep telling my self " This would be a 'go' "
by the way, does anyone know how many times the engines of airliners have failed above 100kts or closer to actual V1...
cheers
Beau_Peep
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it was rhetoric..
Yes, I don't like to give blind importance to stats and I am not going to abort close to V1.. I just wanted to draw attention of the readers to the point that rarely engines fail close to V1 (excluding possibility of bird strike)..
cheers
cheers
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The issue is not SOP or what whoever will do, it is about available
distance to stop if an abort takes place at speed that is above V1
AT 54000 KG??
IF AT 64000 KG , LESS RUNWAY AND 30 KTS MORE SPEED AND STILL
ON PAPER THEIR IS ENOUGH RUNWAY TO STOP THEN at 54000kg
I should be able also to stop at 149 kts safely.
distance to stop if an abort takes place at speed that is above V1
AT 54000 KG??
IF AT 64000 KG , LESS RUNWAY AND 30 KTS MORE SPEED AND STILL
ON PAPER THEIR IS ENOUGH RUNWAY TO STOP THEN at 54000kg
I should be able also to stop at 149 kts safely.
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Tarik,(ssg)
Whenever you are not at the runway limited max take off weight there will be a range of v1 speeds available.
Think of the lowest v1 as the lowest speed you could safely continue the take off after an engine failure and the highest v1 as the highest speed from which you can stop.
Some one decides on a policy of which speed to use and you use it. It may be that the decision is to use "Balanced" speeds in which case if the engine failure occurs at the exact Vef speed used in the calculation then the distance to continue to screen height would be the same as the distance taken to stop.
For all other v1s the distances required are unequal.
Your question about different speeds at different weights makes no sense! Now if you were to ask why can't i stop after a V1min of 119 when the V1max at the same weight is 150 then that would make for an interesting discussion.
as it is you need to study the concept a little more then get back to us.
Whenever you are not at the runway limited max take off weight there will be a range of v1 speeds available.
Think of the lowest v1 as the lowest speed you could safely continue the take off after an engine failure and the highest v1 as the highest speed from which you can stop.
Some one decides on a policy of which speed to use and you use it. It may be that the decision is to use "Balanced" speeds in which case if the engine failure occurs at the exact Vef speed used in the calculation then the distance to continue to screen height would be the same as the distance taken to stop.
For all other v1s the distances required are unequal.
Your question about different speeds at different weights makes no sense! Now if you were to ask why can't i stop after a V1min of 119 when the V1max at the same weight is 150 then that would make for an interesting discussion.
as it is you need to study the concept a little more then get back to us.
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Our company uses the flex+derate for Take-Off where possible. However I am interested as to whether there any any operators who use some sort of software package which would give you all 3 V1's in preflight calculations for some kind of situational awareness.
For instance you are light as in Tarik's example with a low V1 go, but your company gives a balanced field V1 slightly higher. Is there anywhere you could obtain a high V1 stop for the same take-off criteria.
I ask as lets say for instance you get to the V1 low, and soon after get some kind of manfunction (jammed controls, etc...), if you knew what the higher V1 was, lets say the 149 as from the previous example - you might be in a postion to consider the option of relanding/or aborting if still on the ground and not at Vr if say your speed was not at V1 high.
Not sure if such a scenario is accurate or even desirable as it would add a grey area to the idea of V1 being a stop/go concept but I thought I'd ask.
For instance you are light as in Tarik's example with a low V1 go, but your company gives a balanced field V1 slightly higher. Is there anywhere you could obtain a high V1 stop for the same take-off criteria.
I ask as lets say for instance you get to the V1 low, and soon after get some kind of manfunction (jammed controls, etc...), if you knew what the higher V1 was, lets say the 149 as from the previous example - you might be in a postion to consider the option of relanding/or aborting if still on the ground and not at Vr if say your speed was not at V1 high.
Not sure if such a scenario is accurate or even desirable as it would add a grey area to the idea of V1 being a stop/go concept but I thought I'd ask.
My 2 pfennig:
Look at the charts (table?) for the highest TOGW under the existing conditions (assuming full power, no derates/flex which would change everything) and use that V1 as the V1max. It is a rough approxiamation, but the real answer is to get out the charts, probably unavailable to most of us, and compute all the numbers for the TODA, TORA, and ASDA. Compute Vmcg, Vcefs, Vrefusal, accelerate-go, etc. A 20 minute process, if you have the charts and not very useful in an airline environment.
GF
Look at the charts (table?) for the highest TOGW under the existing conditions (assuming full power, no derates/flex which would change everything) and use that V1 as the V1max. It is a rough approxiamation, but the real answer is to get out the charts, probably unavailable to most of us, and compute all the numbers for the TODA, TORA, and ASDA. Compute Vmcg, Vcefs, Vrefusal, accelerate-go, etc. A 20 minute process, if you have the charts and not very useful in an airline environment.
GF
