The TWA L10 at JFK was actually airbourne...throttles were closed and the aircraft landed.
A perfectly flyable aircraft.
However, there was a stickshaker (false) just at liftoff.
Have given this scenario in the simulator, and the pilots seem to cope quite OK.

trytofly - (like the name:D) agreed. There can never be 'legislation' or 'orders' to cope with this topic. It is part of what you take on when you take command.

I agree with others that we do not have a real idea of the ACTUAL stopping performance for a given runway in many cases where V1 is raised to Vr (back to the idea of VSTOP?), but it should be remembered that we are discussing an airborne 'abort' here really, and that has a huge area of uncertainty.

As someone else has said, there's those who died stopping above V1 and there's those that died continuing above V1.

There is a danger the whole subject will become too complex and too much of a training and certification issue to make it more of a hazard than leaving it to the Grim Reaper?

Following on from BOAC, consider that the AFM data and all the charts your airline produces or purchases are based on presumptions which will differ (to a greater or lesser extent) from the book on the actual day.

He who trusts unquestioningly in the book figures will, sooner or later, have a fright or worse.

Far better to have a general understanding of what this is all about and then be able to make sensible risk assessments from day to day and pad the particular takeoff appropriately, consistent with company reality.

Using V1/Vr = 1.0 (ie V1 = Vr) is not a problem provided that the AFM gives data for this case, as many do.

... and we all have seen the end of the runway disappear under the nose .. still on the ground ... and have (just possibly) had our doubts as to the probability of stopping in some circumstances ....

I will say one thing:

rules are for the obedience of fools and the guidance of wise men.

timzsta - who decides who falls into which category? The pilot himself? What do you do with a fool who thinks he is a wise man and breaks the rules foolishly?

I don't condone any platitude which gives a slick justification for breaking rules.

Rules are there for a reason. If the rules do not cover a given situation, then yu are breaking no rules by using your professional judgement.

Anyone who deliberately goes against the rules will be held answerable for the consequences. He must have a good reason to do so.

Rare do we indeed have the wisdom of the basis for the rules flying in the cockpit to interpret when and where they apply.

Thus it is foolhardy to ignore the rules without ever understanding them.

timzsta
 

I see that you are a PPL and airline wannabe, I find your statement:

quote:
--------------------------------------------------------------------------------
rules are for the obedience of fools and the guidance of wise men.
--------------------------------------------------------------------------------

quite frightening.

Fools will obey rules because they don't understand them, only that obedience is required, wise men will be guided by them because they understand their necessity and will, as a consequence, obey them. .

The expression you have quoted is only a comment on the variation of acceptance and not, as is widely thought, a comment on whether to accept or not. (It is also a cop-out used by people who have a problem with authority!;) ).

At the risk of steering the thread off topic, the past several posts lead to a number of areas where a little knowledge can be a dangerous thing.

One area of significance is that of MEL operations.

The MMEL is developed with input from a variety of stakeholders, cut down to the operator's MEL, and then interpreted by the people at the coal face.

With a single MEL situation, operation iaw with the MEL is probably covered pretty well by the MMEL deliberations. Doesn't always work well, though ... as a for instance one airline some years ago on the 737 (as I recall), misread the MEL provisions in respect of nacelle VGs/chines and had an aircraft floating around the system for quite a few days with one chine missing .. a windshear encounter could have proved quite interesting ...

Operation with MULTIPLE MEL snags is a whole different ball game and, I suggest, the average pilot or mechanic is not well placed to make a comprehensive determination as to whether or not it be reasonable to take such a bird on the next sector ...

I thought of this discussion when reading the following article:

Those Dreadful POHs (Part 1)

As the author points out, even the rules were written by a human. That person would have tried to cover every situation, but to do so is impossible. Some situations haven't been invented yet.

A interesting report, pertinent to this thread, is the
TSB Report on a DC10 aborted takeoff after V1 at Vancouver in 1995.

An extract from "Section 1.14.2.3 Decision Making on Flight 17" states:

Post V1 rejected Takeoff
 

I can tell there are a lot of potential crashes in this forum out there....

Ofcourse if you had plenty of runway, wheels on the ground, lose an engine post V1, pull the other throttles back, stop the aircraft.

Trying to continue the flight, put out the fire, try to get some climb gradient out of your one last engine, in the soup, and try to navigate back to an ILS or whatever is just silly, unless it's the best option.

Obviously given weather conditions (zero, zero), no ILS, mountains all around, and a go decision means flying over to another airport, vs stopping the aircraft on the ground...which decision would a smart pilot make?

SOPS are just that...standard operation procedures. What happens when things aren't standard?

Keep in mind if the plane is under max gross, and you did all your balanced field calcs, and you figured the climb gradients, and performance specs for the single engine climbout, and the subsequent hold, and approach, and possible no flap landing, ect, then for sure go ahead and fly the aircraft off.

I have deleted a paragraph here as it contained a modicum of intemperate comment.

When considering the Concorde crash and the decisions of the pilots, it is essential to keep in mind that the situation was extreme and the pilots (as is generally the case) only had a part of the story and had to make their decisions in a very short timeframe. Certainly, the situation was well outside the certification boundaries and whatever decision was taken was going to have a high probability of unpleasant consequences.

Having taken the decision to continue the takeoff, there is ample evidence to indicate that the crew did a first rate job in the stick and rudder work under extremely difficult circumstances.

Consideration of whether a different decision may have produced a better outcome will, and can only, remain a moot point.

Please, ladies and gentlemen, in this forum we strive for rational observation and comment. We will not tolerate posts (or parts thereof) which are grossly intemperate.

JT

Now we don't have the Concorde program.

Have fun.

ssg,
some of your comment's are well out of order. You seem very self opinionated and perhaps a little critical of others around you. However, it's a start having found the CRM forum !!.

ssg

what a load of tripe.

My guess is you've never flown a multi crew airliner and don't really understand the term SOP's. I may be wrong, but that's the impression I get from what you've written.

SOP's help a pilot under pressure when it's all going wrong. They are the bottom line, they help to keep a level of control whilst the mind is working overtime trying to deal with a problem, and they cover 'most' conceiveable events. They also give a commander discretion, whereby he is given the authority to operate 'outside' of SOP's if he feels it is required for safety, and during those non conceiveable events.

They are absolutely not there purely for when it is all going 'standard'.

JT:ok:

M.85

One more related question here...
Having read thorouly about V1,V2 etc..I have remembered that if the Balance field available is greater than the Balance field required,a RANGE of V1 is possible,to be between VGO and VSTOP.
VSTOP being the LAST speed at which one cqn stop the A/C within the TODA,if V1 is BEFORE VSTOP...isnt the difference in speed between the two an extra margin to stop after an engine failure?I can understand the margin to be only a few knots.
Also,if slush at the end of the runway,a smaller V1 is given.
How can a pilot know how these V1 speed have been calculated??

Thank you again,

M.85

mmmmm,
might be somewhat different with a heavy jet where often company policy and airmanship dictates that you use de-rated t/off pwr to save high engine egt's and therefore extend engine life.

V1 is if de-rating calculated so that you can stop before the end of the tarmac, it may well be the case that yes you could stop after v1 but you as a line pilot signing loadsheets etc etc you don't know that to be the case, therefore stick to the sopa's.

V1 and V2 are often no more than 2-5 kts apart on a transport a/c and therefore since v1 is the speed at which the first actions to bring the a/c to a stop should have already been carried out,
by the time you recognise a failure at v1 and made a decision to stop you will probably already be well past v2 and with a 100+ tons of airliner you are well into no mans land and out of a job.

regards

V1 and all that
 

It appears that some or all of us should update our RTO training.

Files from the Boeing / FAA RTO Training guide are here:

Summary viewfoils 752 kb


Section 2 RTOs, V1, decisions, performance, etc 1.8 mb Caution large file; use right click 'Save Target as' option.

Section 2 Wheels, brakes, calls, CRM, etc 1.5 mb Caution large file; use right click 'Save Target as' option.

ALF

Timzsta,

Interesting that nobody commented on your misquotation and consequent inability to even grasp the significance of the correct quote:

"Rules are for the blind obedience of fools and the guidance of wise men"

Captain Stable and BlueEagle have dealt with the essential elements of the debate most adequately.

V speeds are certification speeds based on the engine failure scenario. Their relevance to other events that may occur at critical times is limited to a very important parameter - the energy state of the aircraft during the take-off phase.

Having an indication of whether the aircraft can stop or go is important to your decision making, almost as much as knowing when the indications are no longer relevant. Similarly, we need to be careful in translating the lessons from accidents in certain types into something more generic. While the risks of wing spar burn-through during an uncontrolled engine fire may affect some aircraft, will that justify a greater probability of overrun accidents in many other unrelated types because folks emotively ignore the longer history behind our current thinking on being "go" minded within sensible parameters.

SOPs create a decision framework to aid in the safe development of airmanship and useful experience. They provide some certainty in an occupation teeming with variables and choices. The best advice is to thoroughly understand why they direct you in particular ways - there is little progress without understanding the problem that the SOP tries to resolve or avoid.

Stay Alive

hi alf,

I cant open the file you gave us about the 737 v1 decisions,wheels...etc.
Do you have a website address?

Thanks,

M.85

:ooh: Spooky!! The Clash just played 'Should I stay or should I go now' on the radio while I was reading this thread!!