4th June 2010 B737-800 rejected takeoff after V1 Report is out
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The total experience level was actually quite low in this cockpit.
With lots of time on a specific type one tends to recognize what feels "right", "not right" or what can probably be disregarded. But rejecting after Vr? Someone has seriously not understood the concepts of a balanced take-off or V1. "Decision" being the keyword.
Someone will now come along and claim that 3000 hours is a lot.
Don't embarrass yourself.
With lots of time on a specific type one tends to recognize what feels "right", "not right" or what can probably be disregarded. But rejecting after Vr? Someone has seriously not understood the concepts of a balanced take-off or V1. "Decision" being the keyword.
Someone will now come along and claim that 3000 hours is a lot.
Don't embarrass yourself.
GlueBall, was it a feeling? 
It is interesting to note the points raised by the FO. From the report:
Did he effectively communicate that info to the Captain? That information may remain in house at the company.
According to the first officer when the aircraft reached the V
Also interesting ...
It is interesting to note the points raised by the FO. From the report:
At around 140 knots the pilot flying observed a speed trend vector in the negative direction.
Did he effectively communicate that info to the Captain?
That information may remain in house at the company.
The goal of the investigation was to answer the investigative questions as desribed in chapter 1 paragraph 1.2.2 with the facts that are available. The takeoff roll was described using the available information from the flight data recorder and the statements made by the crew during interviews. Because the Cockpit Voice Recorder was not available there was no factual evidence available that would allow the assessment of the cockpit crew co-ordination. To asses the cockpit crew co-ordination based on statements alone is insufficient.
The captain stated that at the same time he observed a large trend vector in the positive direction.
The captain did not find this discrepancy an issue and made no comments about this. As the airspeed reached V1, the ‘V1‘and ‘VR’ calls were made and the captain removed his hand from the thrust levers.
According to the first officer when the aircraft reached the V
1 speed the control column was moving aft without the application of force. The first officer stated that he experienced back pressure from the column and the aircraft rotated on its own.
At this time he had the feeling that the aircraft was unsafe to fly and pulled back the thrust levers. {My thought: Is this a case of "what's it doing now?" leading to a decision?}
The auto brake system and speed brakes were automatically activated and a rejected takeoff was initiated.
The pilots informed maintenance that there was a airspeed indication problem. Therefore troubleshooting and maintenance actions focused on finding the cause of the unreliable airspeed.
First, an inspection for unreliable airspeed without disturbing the aircraft systems and components was carried out. The result of this test was an airspeed indication disagreement between the left and right side.
First, an inspection for unreliable airspeed without disturbing the aircraft systems and components was carried out. The result of this test was an airspeed indication disagreement between the left and right side.
Next the unreliable airspeed procedure was carried out according to the steps described in the Fault Isolation Manual. To fulfil the requirements and complete the unreliable airspeed test the
right hand angle of attack sensor (alpha vane) required adjustment. The result of the test wassatisfactory and no airspeed disagreement between the left and ride side was found.
Pages 18 through 20 were the most interesting part of the report, to me.
Last edited by Lonewolf_50; 27th Jun 2011 at 15:27.
Worth mentioning that you're talking about a Trident in 1975, not recently. The aircraft left the side of the runway and slewed sideways during the reject after the captain intentionally steered into the grass to avoid going off the end. There were no injuries or fatalities.
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Someone has seriously not understood the concepts of a balanced take-off
How do you know the take off was "balanced"?
Obviously there was some extra stop margin left.
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There may have been a technical issue with the aircraft, but I'm sorry RTO with the nosewheel already in the air is suicidal. Unless the aircraft is disintegrating in flames around you there is absolutely, 100% no excuse for such an action.
Speed trend vectors, airspeed disagreements etc are NOT causes for RTO. Boeing publish an entire unreliable airspeed section of the QRH and sudden speed changes on rotation is covered by a windshear escape manouvre (or manover if you're from over the pond!)
My point being that whatever happened at rotation is covered by SOP, is already covered by memory items and manouvres all of which SHOULD be known and trained, this wasnt a one-off 'think outside the box' incdent.
Instinct is a fine thing and I certainly do not advocate blind obedience to SOP's regardless. But with the nosewheel off the ground for 2 seconds is not the time to go off the reservation.
The only thing that saved them was a long runway, they were Waaaaaaaaaay outside the envelope.
Speed trend vectors, airspeed disagreements etc are NOT causes for RTO. Boeing publish an entire unreliable airspeed section of the QRH and sudden speed changes on rotation is covered by a windshear escape manouvre (or manover if you're from over the pond!)
My point being that whatever happened at rotation is covered by SOP, is already covered by memory items and manouvres all of which SHOULD be known and trained, this wasnt a one-off 'think outside the box' incdent.
Instinct is a fine thing and I certainly do not advocate blind obedience to SOP's regardless. But with the nosewheel off the ground for 2 seconds is not the time to go off the reservation.
The only thing that saved them was a long runway, they were Waaaaaaaaaay outside the envelope.
Is this a case of an FO who has far more 'faith' in his own intuition than understanding of the basics of JAR25 aircraft takeoff performance calculation? Perhaps as early as he felt the autobrake engage, even he knew he had reacted incorrectly.
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Air France did it in a 777 at Lagos a while back after the Captain inadvertently engaged the autopilot during the T/O roll and then found the controls locked at Vr.
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In that case I retract my statement. To my remembrance no particular extra training was conducted during my RST, perhaps due to time constraints.
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Gentlemen, before continuing, I do understand the importance of V1 and SOPS', however, in many cases where there is a long runway, the V1 call is rhetoric (yes, I know its importance) because the rotate call is 1 knot beyond that. In other words, the rotate speed has been reached before the critical point on the runway where there is insufficient length left in which to stop. Obviously, that was the case in this instance.
Perhaps that may have influenced the PF in this case? I know it shouldn't have but that is another matter.
Perhaps that may have influenced the PF in this case? I know it shouldn't have but that is another matter.
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Regardless of airspeed disagreement, speed trends in opposite directions, whatever :-
with both engines still developing T/O thrust, Pitch and Power would have got the aircraft airborne SAFELY.
Or don't they teach F/O's that any more ?
with both engines still developing T/O thrust, Pitch and Power would have got the aircraft airborne SAFELY.
Or don't they teach F/O's that any more ?
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To my remembrance no particular extra training was conducted during my RST, perhaps due to time constraints.
Short runway, max crosswind component, numerous major and minor faults requiring action from the crew in either a go or no go sense. 3 each, 6 in total - surely it's ringing some bells??!!
I remember it well, it was done very well in my session.
Last edited by Cloud Bunny; 28th Jun 2011 at 10:11.
There may have been a technical issue with the aircraft, but I'm sorry RTO with the nosewheel already in the air is suicidal. Unless the aircraft is disintegrating in flames around you there is absolutely, 100% no excuse for such an action.
Reject or not?
2205 ʞɾ ʇɥƃılɟ ɹıɐuɐds ɥʇıʍ pıɹpɐɯ uı pǝɹɹnɔɔo sɐ - ɥsɐɹɔ lɐʇɐɟ puɐ llɐʇs ɐ uı ʇlnsǝɹ plnoɔ ǝʇɐʇoɹ oʇ ʇdɯǝʇʇɐ uɐ ˙(ƃuıʞɹoʍ ʇou ǝɹɐ sƃuıuɹɐʍ ǝɥʇ ƃuıɯnssɐ) ɟɟo-ǝʞɐʇ ɹoɟ ʇǝs ʇou ǝɹɐ sdɐlɟ ǝɥʇ ʇɐɥʇ uoıʇɐɔıpuı ɹoɾɐɯ ǝɥʇ sı sıɥʇ
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Time constraints? Wouldn't have thought so - it was the first thing on the 'list' of things to get done.
Short runway, max crosswind component, numerous major and minor faults requiring action from the crew in either a go or no go sense. 3 each, 6 in total - surely it's ringing some bells??!!
I remember it well, it was done very well in my session.
Short runway, max crosswind component, numerous major and minor faults requiring action from the crew in either a go or no go sense. 3 each, 6 in total - surely it's ringing some bells??!!
I remember it well, it was done very well in my session.
Regardless, I already retracted my statement. Case closed.
My experience is far from extensive and I have never experienced an RTO in my career. If it were up to me, I'd stick to the book in these situations. I will not partake in the blaming game so I'm not judging what happened here. But if it were me, yes, heavy flight controls after Vr is still a continue.
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Find out what allowed it to happen!
Maybe this is a wake up call with regard to the SOP of leaving the throttles unguarded after V1 is announced.
My feelings on this incident is that it was an extremely lucky escape from disaster - a shorter runway and the outcome would have been much worse.
We obviously don't really know precisely what was going through the first officer's mind to cause him to reject the take off. However, safe aviation is based on certain disciplines, many of which have stood the course of time and are based on some very hard experience. In short, if it ain't broke don't fix it!
I only wish 411A was still around - I can imagine what he would have to say!
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Originally Posted by SASKATOON9999
Its better to have rejected and and wish you had not - Than to have not and wished you had!
Let us work this example, using a shorter runway (the only reason that this wasn't a catastrophe) -
1. Crew notice there is an anomaly on scanning the ASI after V1. Crew rightfully continue. Once in the air, the QRH is referred to, and necessary action taken. If needs be, the aircraft can be safely returned to land. Crew think to themselves "Oh, that was a pain to deal with, it would have been nice if I had noticed the anomaly before 80kts, ideally."
or,
2. Crew notice there is an anomaly on scanning the ASI after V1. Crew abort the takeoff, and the aircraft goes sliding off the end of the runway, through obstacles, and winds up as a burning metal sculpture. Crew think to themselves "better to have rejected and wish I hadn't rather than..."
Oh wait, no they don't. They're dead.
Hope this helps.
In the same context, If we could ask the crew of the Air France Concorde crash if they would have still taken the aircraft into the air or rejected? Oh no we cant, there dead! Overrun, significant damage and death all distinct possibilities, but the chances would be in favour of staying on terra firma!
Aero Peru 757 crew - Im betting the same. This said, every situation is distinctly different and the parameters are almost impossible to measure against each other.
- I've never heard either company say that you should take an unflyable aircraft into the sky if you susspect a major control problem to have occurred?
Aero Peru 757 crew - Im betting the same. This said, every situation is distinctly different and the parameters are almost impossible to measure against each other.
Boeing, Airbus and all of their operators disagree with you in this context