Since we're thinking "out of the box"...

What's the proper action if, after V1 but prior to Vr, the aircraft suffers a malfunction that causes it to slow back down below V1? Then can you "legally" abort?

As Stated earlier the time between V1 and Vr is so small you are most likely going.. as one of my riddle professors use to say Measure with a Micrometer and cut it with an AX


Fly safe yall

Well if you're below rotation speed it probably won't fly. But the point in space is still behind you(original V1 point). So the 2nd V1 indication really has no meaning. However, I'm not worried about legal if there's an uncommanded deceleration on my takeoff roll.

You are right I think I was given a stagnating airspeed on TO roll in the sim out of LGA before we knew it we were dang near in the Drink I think the point the instructor was trying to make was we could have started the rotation but at a much slower rate than normal.. talk about pucker factor

Most of the posts here have been examples of anything but 'thinking outside the box'...in fact, they have been nothing but parroting of rote procedure.

A Captain's emergency authority is there for situations like this one...where circumstances that might be considered written in stone may not be. Depending on what those circumstances are, I see no problem with a rejected takeoff at V1.

All things considered, E1Out's post reflects the best grasp of real world reality.

Funny, I though we we're talking about after V1. :rolleyes:

Either way, if you have a problem with pilots thinking outside the box then don't fly with the Chinese.

Are we really going to split RCH's on this one? :eek:
There are always exception but in general, I'm most likely going to play the percentages and take her into the air. I usually need the landings anyway.:D

I agree with Subicpilot

If I have a Valuejet fire, now I know about it, (they didn't) but I still cannot fight the fire. Thinking about how close the DC-8 came to crashing in PHL last year with a cargo fire. My ops thinking is like my Navy training. I would evaluate the runway environment, flat, smooth over run?, Good CFR folks on station? Wx.. is it VFR and I can immediately turn downwind? or will I have to go out and set up for a possible lost com ILS etc? No same answer depending on environment and crew capability (yes, our reputations precede us <g>) But if I get a cargo fire, I would rather do the Tradewinds off runway excursion and jump out than crash like Valuejet turning around.
In any case, under normal training RTO procedures, one should think seriously about conducting high speed RTO's (above 80-100 kias) because they get dangerous the higher the energy state. In my case, if I blow a few tires at 100 kts, I am going flying, not doing an RTO that likely takes me off the RY anyway. This is all great layover/training center discussion BTW. For the original poster, I would have taken it airborne <g>

The industry came up with the Takeoff Safety Training Aid in the early 90's. Here is what Boeing put out about it.
"Takeoff safety
A flight crew may reject a takeoff for a variety of reasons, including engine failure, direction from air traffic control, blown tires, or system warnings. A takeoff under these conditions may result in a diversion or delay, but landings are usually uneventful. In about 55 percent of rejected takeoffs (RTOs) the airplane would have had an uneventful landing if the takeoff had gone ahead.

While most RTOs are without incident, they do account for a significant number of accidents, as well as damage to the airplane. Following are some statistics about RTO accidents and incidents:


More than half the RTO accidents and incidents reported in the past 30 years were initiated from a speed in excess of the maximum "go/no go" speed before the airplane must take off.

Approximately one-third reportedly occurred on runways that were wet or contaminated with snow or ice.

A little over one-fourth of RTO accidents and incidents were caused by loss of engine thrust.

Almost one-fourth of RTO accidents and incidents were the result of wheel or tire failures.

Approximately 80 percent of RTO overrun events could have been prevented by appropriate operational practices.
An RTO occurs approximately once in every 3,000 takeoffs. However, many RTOs may not be reported; the actual number may be estimated at one in 2,000 takeoffs. While RTO overrun accidents and incidents persist, the rate of occurrence continues to drop. Compared to the 1960s, the 1990s showed a 78 percent decrease in the rate of RTO overrun accidents and incidents.

In 1992, with the endorsement of the FAA, Boeing, along with members of the aviation industry, published the Takeoff Safety Training Aid. The aim of this training aid is to reduce the number of overrun accidents and incidents resulting from high-speed rejected takeoffs. Boeing and members of the aviation industry also formed an international takeoff safety task force that recommended developing training practices and operational guidelines and improving how the full-flight simulator is used.

Engine, tire and brake suppliers are also working to improve their products. The airlines are continuing to develop effective training in the areas of takeoff decision-making and how to handle rejected takeoffs."

The concepts are covered in Advisory Circular 120-62 found here: http://rgl.faa.gov/Regulatory_and_Gu...0!OpenDocument

The original post said it this way..."We received the engine fire notification the second we hit v1".

The type of aircraft, length of runway, and exact point of the emergency all justify the POV that this is not a black and white question.

Any Captain that taxis out onto the runway with the idea that an engine failure is a canned situation is in the wrong seat.

V1 is a decision speed. Simple.

If, as others have noted, you have a 5 mile long runway, you can brief, "We don't have a V1 speed so if anything happens prior to liftoff, we will abort."

BUT if you are going to computer a V1 speed, if expectations are that anything prior, you abort and anything after, you go... you do as briefed.

At or near V1 you are accelerating at about 7-10kts per second. Not a time to begin discussions on whether to go or to abort. There are more than a few airframes that got bent because guys were sure they had enough runway.

now not having the book right infront of me but, the definition of V1 is the speed at which if an engine failure occurs, the aircraft will be able to take off and accelerate to a safe climb speed (V2) by reaching 35 feet agl at the end of the runway. this is specifically regarding the performance of the airplane in getting to 35 feet within a set distance (the runway length). This speed by definition has nothing to do with other mechanical failures (ie tires, flight controls, fires). For example when the concord blew that tire, was it smart to take off above V1 and have an uncontrolled fire in the wing? What if the airplane doesnt even rotate at V1 like the CHQ 145 on christmas eve at JFK. They had to abort and thankfully they were at JFK and not LGA. Now im not saying for something stupid we should abort a takeoff above V1. The laws of physics say taking a 30-75,000 pound object at 120 knots and bringing it to a stop will be a tricky situation at best because of all the energy (KE=1/2mv^2). But is it worth adding the potetial energy of gitting a conditionally non flyable object into the air and then adding more energy into the mix. As was said earlier thats where the grey area and the captains pay comes into it.

I don't agree that this is a situation requiring a Captain's emergency authority. A light indicating an engine fire illuminates at V1. Why would you reject the takeoff?

I really think the situation is the key. Know your airplane and know what you are working with. In a SAAB I doubt it would matter very much that he aborted the takeoff. That airplane is never really going to have a true V1 speed anyway. There is no way that a SAAB is going to have a field length limit problem on that long of a runway (unless you took off from an intersection of course). We have V speeds for a reason yes, but in this case the V1 speed is really only there because it has to be at or before Vr.

In the 744 we almost always have a pretty large split between V1 and Vr. In my airplane there is no way I would abort above V1. The end of the runway is coming up awfully fast!

The Tradewinds accident is exactly what happens when you abort after V1. They had 3 good engines but still aborted well after V1.

What is being suggested in this discussion is that this situation may not be one where hidebound responses need always apply.

I didn't say that this situation required the use of a Captain's emergency authority...I said it was a situation where that discretion might be used because of certain parameters (aircraft braking characteristics, runway length, etc).

Because the Captain determines that this is a prudent course of action based on the circumstances.

No one is arguing against the basic wisdom of the convention that says a takeoff should be continued when an engine fails above V1. All that is being said is that this is not always a black and white issue.

As for those who have tossed in the energy aspect, they have missed one little point. It's not unusual for our V1 and Vapp speeds to be similar...energy is energy. Yes, there are other factors such as position on the runway and associated drag of landing flaps versus takeoff flaps...but if we assume that the V1 stopping weight will be similar to the 'return to an immediate landing' weight, then energy issues become less significant. Stopping a 70,000# aircraft going 130KIAS is much the same in either instance.

Lastly, some have stated that a check airman would consider this decision an automatic unsat. I certainly hope not. I've been giving checkrides since 1971...the last thing we need is an evaluator who sees only the 'book' in situations such as this. Too often, however, this is the outcome, and it doesn't serve the interests of the evaluation process or those being evaluated.

Statistically if you abort after V1 you WILL kill people. AllOfTourTraining teaches you to continue why abort? The aircraft is certified to burn and you can elect to do nothing until flap retraction altitude. There's no way I would stop after V1. There is too much documentation of crews take it off the side/end of the runway during a high energy abort.

There are circumstances posted in this forum that would make aborting after V1 a viable option. Never say never. There are exceptions to almost every rule, and the training we receive does not cover all circumstances...

Training gives you the tools to make good decisions. It works most of the time, but nothing takes the place of sound judgment (that statement is probably in your flight manual or operations manual somewhere...)

I have a good friend that rejected below V1 that put a jet in the dirt in the overrun.

And incidentally, who's to say that because you reject after V1 and take it four wheeling, and perhaps injure or even kill someone, that the outcome if you had taken it flying would not be exponentially worse?

I sometimes wonder if my last go-around was really necessary...but then it's always better to wonder that, than to be sitting there amongst the wreckage and know it for certain.:rolleyes:

Correct, and I agree except there are circumstances as I previously posted in this thread that I will Reject for at V1 or if still on RWY: cargo compartment fire with known dangerous goods that could logically aggravate said fire (ala Valuejet) with TO alt required, good runway environment (dry, flat etc). Will take my chance ala the Tradewinds 747 off RWY excursion in the Youtube video also posted in this thread. In that scenario, most probably crash off airport anyway that will often endanger innocent folks. I fly cargo though with more dangerous materials allowed than pax ops.
Still agree with Subic <g>

NOTHING is absolute.... nor is there a substitute for experience...but then just how many of us have actually experienced an engine fire indication IN THE aircraft....much less exactly at V1......

Certainly a catastrophic failure may deem in necessary to accomplish a high speed abort... but v1 is there for a reason in the vast overwhelming majority of cases..... black and white?..no, but damn near.

There is a lot more to the TDX crash than appears in the video. They are lucky they didn't die on that abort. If the ground had not been soaking wet the aircraft would have plunged off the drop-off just past the airport fence. That was a case of why you WOULD NOT abort past V1.

Absolutely agree, was commenting that in the case I posted, (cargo fire with many other circumstances) I believe I would be better off staying on the ground than crashing ala Valuejet. Any engine failure I get AT V1 or above I will go flying. Simply saying like many, reason they have humans, is to make a decision that is not planned for in the normal course of training. Every AOM/POM says they cannot plan every contingency or emergency. i.e. multiple compound emergency event (ala UAL Capt Haynes DC10 flight)

Every case is unique. On the one hand, there is what the Reg's say in black and white. On the other hand is your best judgement. Sure, the FAA can always come after you for aborting at/slightly after V1, even if you save the Aircraft and everyone on it...but I think most Pilots would rather face that acquisition than not being able to at all, because you tried taking an Aircraft airborne that just wouldn't fly.

Remember that American DC-10 that lost it's left engine on takeoff? The crew did everything by the book, which is exactly what killed them. Just something to think about.

this is true, but thats because what happened to them was not even in the book. when the engine separated, it took the slat with it. McDonnell Douglas says that if they had flown V2+10 they would have made it. It was subsequently written into the checklist that if you lose an engine on T/O AND you get a slat disagree, you fly V2+10. Unfortunately, however, the sim cant be programmed to give you this on takeoff, so DC and KC-10 crews are only verbally trained on this scenario.

anyhow sticking to the book is the necessary start for a standard scenario, and then if thats not working because of a compound emergency or something thats not in the book, thats where you have to use experience and knowledge of your airplane to stay alive

It took the slat and cut the left wing's hydraulics. Remaining slats and flaps retracted, left wing stalled. Down we go.

What is the TO distance and the lndg dist for a saab? With 14.500 feet of runway it seems to me like you can TO and land without making a turn. Never read a book that states you have to make a turn or fly a pattern with a burning engine / wing... The "most suitable runway" could be the 7000' straight in front of you, 35' below you, no?? The V1 speed is not pr. definition in a turboprop of that size with a 14.500' of runway anyway...

Here is a good one in the SAAB that I got. V1..Rotate pull up airplane won't pull up jammed elevator. I aborted and stopped. Other pilots I have heard try to take it airborne, using trim or trying to disconnect the interconncect unit and they had to put another quarter in. Point is there are some scernarios where you would abort after V1. I agree engine fire indication take it in the air may just be a faulty indication.
PS Colgan Rules and I rule

Would you add to the end of your brief:

"At or after V1, we'll continue...if the laws of physics allow, otherwise we'll unbuckle from what remains of our flight deck seats after the crash and run like H E double hockey sticks."

??

So how many seconds after V1 do you abort. You have to draw the line somewhere and thats what V1 is... Continue and come back and land 5 min later. :eek:

Zero seconds after V1
 

Thrust or power lever hand on yoke or lap at V1.....

If the aircraft is incapable of flight, its incapable of flight. If you have to take it into the weeds, so be it...you're left with two choices, crash under some control or crash out of control. Flying is not an option (jammed flight controls, loss of all engines (or 3 of 4 in a 4 engine), and probably some freak accident that no one has thought of). How do you lose all your engines? Flock of geese, FOD, or fuel contamination.

The (extremely few) scenarios where you would abort after V1 continue to infinity seconds after, if that answers your question. Regardless, its not like it takes 20 seconds after V1 to figure it out...jet won't fly, Abort. Go through the fence at 100 knots with brakes on vs. nosing into the ground in a stall at 150 knots.

There is a reason its called "decision speed" not "do not abort speed." And its easy to brief..."We will be committed to the takeoff after V1 unless the aircraft is incapable of flight."

Very good discussion. I have this book called "Professional Pilot" written by John Lowery, I think some excerpts from his book might help add to the discussion.


"It must be emphasized, however, that V1 is based solely on engine failure. It is not designed to account for other failures and malfunctions. Tire failure in particular is a very serious event at high speeds. Thus a reject decision with a blown tire must not be made based on V1. Instead, after a certain point it is infinitely better to continue takeoff than to reject. In addition, with a blown tire you lack the traction needed to duplicate the published Balanced Field Length (BFL)." page 61

"Many Pilots harbor the opinion that it is always safer to continue takeoff if you are anywhere close to V1. Captain WIlliam W. Melvin, Delta Airlines, writing in ISASI FORUM magazine, tells of an airline instructor known for giving pilots with a known "accelerate-go" mindset an engine failure below Vef. This exercise, he states, always ended in a practice accident." page 62-63

FAA advisory circular Draft A.C. 120-62 (September 9, 1994), Take Off Safety Training Aid, cautions against using V1 as decision speed. Instead, V1 is defined as follows:

1) The maximum speed by which a rejected takeoff must be initiated to assure that a safe stop can be completed within the remaining runway ... and stopway.

2) The minimum speed that assures takeoff can be safely completed within the remaining runway ... and clearway, after failure of the most critical engine at a designated speed.

3) The single speed that permits a successful stop or continued takeoff when operating at the minimum allowable field length for a particular weight.


"Many Pilots harbor the opinion that it is always safer to continue takeoff if you are anywhere close to V1. Captain WIlliam W. Melvin, Delta Airlines, writing in ISASI FORUM magazine, tells of an airline instructor known for giving pilots with a known "accelerate-go" mindset an engine failure below Vef. This exercise, he states, always ended in a practice accident." page 62-63

He summarizes on page 69 by saying the following: "The most important thing to remember is that V1 is not decision speed; rather it is a performance speed. Both the accelerate-stop and accelerate-go distances are calculated from V1. Your RTO decision must be made prior to reaching V1, with the first action to reject takeoff occurring not later than V1. Once you have reached V1 accelerating, you have made the GO decision. Remember too, V1 relates solely to engine failure which is statistically rare with turbine engines.

V1 is not "engine failure recognition speed." Rather it is the speed at which, according to Boeing, "... the pilot's application of the first retarding means during the accelerate stop maneuver." In other words, you must be on the brakes at V1.

And, above all, remember that your decision to initiate a high-speed RTO must be because you feel the airplane is incapable of flying.

Plan for every departure based on worst-case situation. This will eliminate both surprises and accidents."

I am glad we are all professional pilots and this is all so crystal clear.

Tell that to the concord that went through an apartment building.

When I was at Flight Safety one thing they hammered was that not every circumstance can be covered by a small list of procedures. There are other instances where aircraft would have made it had they not decided to takeoff. In the sim do what you're suppose to but in real life I feel the CA is still the final authority. If you have a couple miles of airstrip in front of you there's no reason you can't come to a stop. You fly in the airplane in and land on smaller strips than that at higher speeds with no problems. Why risk taking off and melting the thing when you know you can easily stop in the remaining distance? You could stop, deplane, and run from the thing before you even got on final to make your landing. Those checklist are made on statistics but that's why robots aren't flying the things. Some circumstances might require alternate actions. I'd rather live to argue it than die with others knowing, "He did everything right there just wasn't enough time".

You oughta be thanking the FnAA for the mess of Aviation Regulation.

... ok?????

A couple of points to add:

In my 8 (short) years of flying transport cat aircraft, I have yet to be able to figure out "exactly" how much runway I'm going to need without going to the books. When you're zipping down the pavement at 110+ knots can you really tell if you're going to stop if you hit the brakes?

I've done a high speed abort in the CRJ. It was initiated shortly after 120 knots (a full 28 knots before V1) after receiving a red "Passenger Door" master warning. I'll tell you that the event was something that was quite uncomfortable for me, the rest of the crew and the passengers. I'll also say that we used up EVERY BIT of available runway 1L at IAD (11,500 feet) using heavy braking. It's not particularly something that I want to duplicate anytime soon.

What do you do when your V1 is significantly different from Vr? (In the CRJ I once had a V1 of about 85 knots and a VR of 135 knots- the difference was due to runway contamination and reduced abort stopping capability.)

My former employer, and my current one (after input from myself) call out "V1" 5 knots prior to reaching the speed, in order to allow "decision delay" time. The thought is by the time that the PNF makes the call and it is processed by the PF, V1 has come and gone. At that point, the PF removes their hand from the thrust levers and waits for Vr.

There have been some very valid points made, but at the end of the day, if the airplane will fly when we reach V1 (and after it), we're going flying.

Good thread, good reading on topic:
http://www.flightsafety.org/fsd/fsd_jan93.pdf

Blindly following procedure can kill you. Exercise your best judgment. That's why you are sitting in the left seat.

I am sure you are familiar with the recent CHQ ERJ abort at LGA that was 6+ kts above V1 due to the elevator controls being inop. That CA did an exceptional job realizing that although they were above V1, there is no way the aircraft was going to become airborne.

That incident prompted the recent AD for the entire ERJ fleet (inspection of both sets of elevator cables).

I have also had a situation in the sim with wind shear on the runway that caused the speed to never build.

I think everyone has covered this in the "if the airplane won't fly" exemption. Otherwise after v1 you're better off going, as previously mentioned you'll be at a much lower energy level when you come back around for landing. At 120+ knots is not the time to say hmmm...i think....it might be ..... better to.... stop on the runway. now you're aborting from an even higher speed.

Okay:

1) I think that pilots are slowly evolving to become braindead. It's always procedure-procedure-procedure. Gone are the days before all that, when pilots used good judgement...

2) To all the people using the concorde as an example for T/O after V1;
The average takeoff speed of the Concorde is about 220 knots. Considering that the longest runway length at LFPG is about 13,000 feet long, it is a safe assumption that the Concorde would have used the majority, if not almost all of that runway to take off (especially since there was a tailwind at the time of departure).

1 of their engines was completely shut down, and they would have had minimal braking and reverse thrust. If they had aborted the take-off, they would have crashed several major roads, populated areas, and streams.

Either way, there's nothing the crew could have done to prevent the accident. So please stop using this as a valid example.