minimum_wage;
My sources tell me the A/P was engaged and the S/O called the abort.
T
his is a matter of terminology I guess, but the third pilot, where carried, is commonly known a Relief Pilot or Cruise pilot. The Captain, nobody else, calls the reject, unless it's a training situation with the training captain in the right seat. That situation calls for very clear understanding as to who will reject the takeoff and crisp cockpit discipline.
safetypee;
I'm sure you will have pondered this already, but in circumstances such as an inadvertent autopilot engagement on the runway during takeoff where it may not be known until the control column is moved rearwards for the purposes of the rotation manoeuvre that the control column cannot be moved due to such engagement, I think you will agree that there is no time to consider if the autopilot would disengage such that rotation can be executed. I don't know what the right answer is nor do any of us, for sure. By definition, Vr is past V1, and keeping the above comments from ASRAAM in mind, and your comments, thus:
Perhaps removing the ‘what if’ scenarios from the reasons to reject would reduce the occurrence of weak assessment or poor choice of action; particularly if these scenarios are already covered by the assumptions in the basis safety for aircraft certification (FAR/CS), i.e. systems and control redundancy. What is the probability that such an event (what if) will be encountered in operations? The TSTA did not identify any event where an inappropriate RTO would have resulted in the aircraft being unable to fly.
, and the TSTA statements, “
… unless the pilot has reasons to conclude that the aircraft is unsafe or unable to fly. ” (para 2.3.1.2), as well as the FAR/CS for the aircraft, I would concur with reducing the reasons/requirements for a reject above
100kts, I would acknowledge the SOPs as providing the legal freedom, (not authority - the captain already has that), to conduct a reject for "unsafe/unable-to-fly" reasons but would suggest that not all such circumstances have been examined which would provide guidance for crews rejecting for this last category.
A Canadian Airlines DC10 rejected a takeoff right near V1 in Vancouver due to a loud, explosive noise which turned out to be a compressor stall. The aircraft overran the runway and while substantially damaged, all evacuated successfully. In the context of this thread, it is worth quoting the
Canadian TSB Report briefly:
The captain's decision to reject the take-off was based on his perception of the circumstances. The influences that could have shaped his understanding of the situation were his training and experience, his perceptions as to flexibility provided by the use of C2B power, and the available visual and aural cues. In addition, the wording contained in the CAI DC-10 FCOM, that a "further 3 seconds is allowed until full braking with spoiler actuation is attained," may be ambiguous in that it implies that some time beyond V1 is available for the pilot reaction. The limited published information regarding the inevitability of an overrun when a take-off is rejected beyond the V1 speed could also lead to this adverse consequence not being considered in the decision to reject.
The captain's understanding was that an engine failure would not be an adequate reason to initiate a rejected take-off after V1. In this case, however, prior to making his reject decision, he did not see or perceive indications, or hear advice from his crew, that an engine failure had occurred. Also, the loud bang was neither similar to any compressor stall symptom that he knew about, nor similar to sounds that he had heard in training or experienced during actual flying.
All the members of the flight crew reported that the sound was unlike anything they had heard before. Not only was the bang very loud, but it was difficult to specify its point of origin. None of the crew saw the engine fail light illuminate<23>, nor did they notice the drop in N1. The only cue the captain received to indicate that the take-off was no longer normal was the loud bang, followed by a series of thuds and vibrations. Because the situation did not match any of the captain's previous training or actual flying experience, he was required to respond instantly to the situation by drawing on whatever knowledge or other experience he had.
When the captain heard the loud bang, he immediately thought of a bomb. The only procedural guidance available for this circumstance was that a rejected take-off after V1 could be initiated when "the captain believes that the aircraft has suffered catastrophic failure and will not fly." According to the captain, his action was probably also influenced by the fatal DC8 occurrence that he had witnessed and which resulted in his mental rule of thumb that if structural failure were suspected, he would not take the aircraft into the air.
When the captain decided to reject the take-off, it was his correct belief that, because they were using C2B power figures, the aircraft would have reached the 164-knot V1 earlier, and that there would be additional runway available for the reject. Based on this fact and his visual impression of the runway available, he was confident that the aircraft would be able to stop on the runway.
To my knowledge and all previous experience in rejected takeoffs executed in the simulator, no training nor discussion was provided for other than engine failure or fire at some point in the takeoff. Sometimes a loud noise accompanied an engine failure. There was never the "unsafe to fly" factor introduced which was intended to cause a reject. I suspect this is the case with most simulator recurrent sessions because that is what is examined in IFR and PPC (for others, Pilot Proficiency Checks - aircraft-specific procedures) rides.
Just to complete the discusssion along this line, I can recall one session where, in the A320, the
Captain's sidestick went u/s, (there is now a Master Caution but if I recall, there was none at the time, (18 years ago) and when I went to rotate nothing happened. Control was instantly given (commanded) to the F/O, with the word, "Rotate" and that was that. Had we rejected, we would have overrun - had the F/O's sidestick also been inoperative we would have been in trouble.
So....I should think that, under the circumstances of this reject (Tokyo ANZ B777), a control column that would not permit movement aft would be accompanied by exceptional surprise and an instantaneous decision, which, in this case, was the correct one because it worked and which would take the engineers and aerodynamicists months to tell us why, which would almost certainly not be sufficiently applicable to another case of autopilot engagement, should it occur.
Which returns us to the original point above concerning what
necessarily renders an aircraft unsafe to fly and what should not be cause for a reject even when surprise is the primary motivating factor?
There is already good guidance on tire failure, (continue, due reduced braking and a full runway for landing), but not on shrapnel damage so it is always a guess and experience cannot lend too much of a hand. Do we "triage" the event by computer-projecting various tire delaminations? Any such work must include degradation of warning systems as well as structural parts. In Toronto, a DC9 overran a runway in 1978 when one of the red gear unsafe lights came on as a result of a tire delamination which damaged the gear proximity warning switches and also caused initial failure of one of the engines, (which recovered after the reject decision was made). The decision to reject was made very near V1 on a max-gross takeoff and the aircraft overran into the same gulley that AF overran into a couple of years ago.
Do we examine flap structures for flyability after substantial damage? Again, there are cases which may apply.
Your original point however is key; are the goalposts moving within airline operations departments without substantive research, and are certification standards fully comprehended by both airline flight operations departments and crews? While certified performance is always pristine in terms of substantiation, we all know that actual rejects are far messier and unpredictable. The narrowing of factors which should cause a reject becomes a single point at V1 - what that point is in terms of engine performance is well understood, relatively clear and trained for; what the point is for aircraft performance and "flyability" is not researched so there are no rote procedures for guidance and therefore relies almost solely on those factors observed in posts above: experience.
PJ2