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  • Gabriel
    replied
    Originally posted by 3WE View Post
    I had hoped you would comment on what the procedure should be to declare, "This looks funny, go to 100% power" and "This looks bad, give her all she's got Scotty, to hell with the di-lithium crystals."
    It is a complicated issue. If you are below 100ks or 80kts (depending what each operator considers the limit for a "high speed" abort) you should abort for any doubt or concern, and probably you will stop on the runay even if you lost a few thousand feet by departing from an intersection that was unaccounted for. Now, if you notice the problem later, and judge that the plane will be "unable to fly", you whould abort at any speed, the idea being that it is better to crash slower and while slowing down than faster and speeding up, which certain Bizplane take-off accident last year proved it is not always really better.

    In the end, the PIC has PIC authority to do whatever they judge necessary in the name of the safety, and it is very difficult to procedurize judgement in every situation.

    These is one of the situations that the only way to deal with them effectivelly is not to let them happen in the first place.

    But, I agree, the moment they said "hey this looks odd" they should have done SOMETHING, be it abort or go full coal.

    Originally posted by God
    I know your deeds, that you are neither cold nor hot; I wish that you were cold or hot. So because you are lukewarm, and neither hot nor cold, I will spit you out of My mouth.

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  • 3WE
    replied
    Originally posted by Gabriel View Post
    Yes, but...
    I had hoped you would comment on what the procedure should be to declare, "This looks funny, go to 100% power" and "This looks bad, give her all she's got Scotty, to hell with the di-lithium crystals."

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  • Evan
    replied
    Originally posted by Gabriel View Post
    ATC provided push back clearance and engine start clearance, the re-programming of the FMGS, that had been postponed earlier, did thus not happen. The first officer was convinced the intersection takeoff data had been entered into the FMGS.
    I might like to see an AD for mandatory Post-It note dispensers.

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  • Gabriel
    replied
    Originally posted by 3WE View Post
    Still- 100 ft over the end of the threshold...just looks like a well-planned, and well-executed tight (ok, very tight) takeoff.
    Yes, but remember that the take-off performance takes into account not everything going well, but what happens if you abort 1knt short ov V1 or continue with an engine failing 1knt after V1.

    These guys lost that layer of swis cheese, and had something like that happened they would be a smoking hole in the ground.

    Kuddos to them for self-reporting their mistake,

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  • 3WE
    replied
    Originally posted by Gabriel View Post
    Yet another one, although this would have been a tough (impossible) one for a classic TOPMS that just compares real take-off performance with the one assumed for the calculations.
    Along with Evan's TPMS I-pad app, I think we need to be sure that all "during takeoff checklists" customized for every type and sub type, with no underlying fundamental links...

    ...that the checklists have a procedure to evaluate, and promptly go to 100% power if things look a little bit off, and if things look truly dangerous, WE should go to 130%/whatever/it's-better-than-crashing-the-plane-even-though-you-are-trashing-the-engines power (if available on the particular type). (Of course, these procedures probably already exist, and should be discussed during the pre-takeoff briefing in accordance with good CRM.)

    Although, this is a lot of extra stuff to distract Boeing Bobby as he concentrates on his finely-honed seat-of-the-pants senses during one of the most critical phases of getting his giant 747-236B (Bigextrafuselageontop) airborne.

    Still- 100 ft over the end of the threshold...just looks like a well-planned, and well-executed tight (ok, very tight) takeoff.

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  • Gabriel
    replied
    Yet another one, although this would have been a tough (impossible) one for a classic TOPMS that just compares real take-off performance with the one assumed for the calculations.

    The SUST reported that the captain (46, ATPL, 9,611 hours total, 1,624 hours on type) prepared the aircraft for a full length takeoff with reduced engine power, the relevant data were computed and entered into the flight guidance system. The crew subsequently briefed the takeoff, dueing the briefing it emerged that the takeoff mass was lower than initially anticipated and the captain decided to review an intersection F takeoff. The data for the intersection takeoff were computed and initially put on paper, the actual programming of the FMGS was postponed as the captain was distracted by a handling agent informing the crew of a missing passenger. The commander left the cockpit to take care of the matter and returned to the cockpit about 10 minutes later. ATC provided push back clearance and engine start clearance, the re-programming of the FMGS, that had been postponed earlier, did thus not happen. The first officer (33, ATPL, 2,185 hours total, 1,335 hours on type) was convinced the intersection takeoff data had been entered into the FMGS.

    The crew requested an intersection F takeoff and when asked whether they were ready for an immediate takeoff (ahead of the preceding aircraft that was still taxiing for a full length takeoff) the crew accepted and was cleared for an immediate takeoff from intersection F.

    The crew commenced takeoff, both pilots noticed the remaining runway was unusually short, however no power adjustments were made. V1 was reached 700 meters before the runway end, the aircraft became airborne 350 meters before the runway end and crossed the runway end at a radio altitude of 104 feet.

    The flight crew discussed their observations but still did not recognize the error. Near the end of the flight duties the commander recognized the possible mistake, informed the first officer and the safety pilot. Based on the data it was then possible to confirm that the takeoff in Porto had been done with insufficient engine power.

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  • Evan
    replied
    Originally posted by Gabriel View Post
    Easy. The plane must have accelerated much more slowly since its mass was pax + baggage + cargo + fuel heavier than the weight assumed in the calculation (just empty weight). The TOPMS would have monitored the acceleration and caught the difference between the one supposed by the calculation and the real one. That's almost the very definition of the TOPMS.
    Ahh, yes. It could always calculate the assumed weight and project performance from the V-speeds entered.

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  • 3WE
    replied
    Originally posted by Gabriel View Post
    ...These were the wrongly calculated take-off speeds:
    V1: 118 KIAS
    Vr: 118 KIAS
    V2: 126 KIAS

    Seriously? Had the wrong calculation delivered 40 KIAS, 40 KIAS, 50 KIAS they would also have attempted to rotate at 50???? Anybody with the slightest idea general performance of jet airliners knows that these are not speeds for a Madrid to Mexico trip. Not in the 767 (incident plane), not in a 737, not in a A380. The crew was not very experienced, but do you really need to be very experience to note it?...
    Procedurally-numbed, puppy-mill robots. Pretty much did it by the book, except for a brief brain fart. Remember the procedure and nail the V-speeds, and be ready for that V-1 engine cut.

    Go through the motions, recite the memory checklists from the FCOM for the type and dash-sub-type, forget about broad, fundamental, cowboy airmanship things.

    (And, they did not have BBFCGMTPMS (Boeing Bobby's Finely Calibrated Gluteus Maximus Takeoff Performance Monitoring System)...yawn.)

    And in comparative terms, this isn't as bad as a 5-minute, relentless, deliberate pull up (what in the hell are they thinking, did they REALLY forget their first flying lesson? ), now is it?

    Such contrast with the light plane version: When it's ready (and you'll know), haul it up. (Of course, what also is done, but not recited, is a glance at the ASI to see that it's in green territory and being ready to reduce back pressure (slightly) if the stall horn beeps).

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  • Gabriel
    replied
    Originally posted by Evan View Post
    I don't how a TOPMS is going to help if the calculations themselves are wrong.
    Easy. The plane must have accelerated much more slowly since its mass was pax + baggage + cargo + fuel heavier than the weight assumed in the calculation (just empty weight). The TOPMS would have monitored the acceleration and caught the difference between the one supposed by the calculation and the real one. That's almost the very definition of the TOPMS.

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    Lack of TOPMS again... The clock is clicking... only time until we have deaths again.

    1- These were the wrongly calculated take-off speeds:
    V1: 118 KIAS
    Vr: 118 KIAS
    V2: 126 KIAS
    I don't how a TOPMS is going to help if the calculations themselves are wrong. I would want to see a cross check by the computer and an alert if there is a significant discrepency. Man and machine, working together.

    But this was much more than a calculation error. This was a clusterf*ck of epic proportions.

    Passengers in the back of the cabin reacted confused and increasingly alarmed with no announcement made by the crew. Several minutes into the flight the passenger oxygen masks dropped (see photo below) together with the announcement "put on your mask and breath normally", the aircraft obviously stopped the climb and rapidly descended, a short time later an announcement "10,000 feet" was heard, cabin crew announced passengers could not remove their masks, the cockpit announced now they were returning to Madrid but provided no reason.
    Yes. Keep your mask on below 10,000 and breath normally while you wonder what the hell is going on. That's all you need to know for now.

    Back to Cat 2 hombres?

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  • Gabriel
    replied
    Lack of TOPMS again... The clock is clicking... only time until we have deaths again.

    The accident occurred because the aircraft rotated at a much lower speed than necessary. Vr had been computed incorrectly during flight preparation based on the zero fuel weight rather than the takeoff weight. The error was not detected by the crew when the data were inserted into the flight management system.


    Controladores Aereos
    Source: The Aviation Herald http://avherald.com/h?article=460db38a&opt=0

    Leaving aside the discussion about performance calculation and monitoring, I want to highlight a couple of things that baffle me:

    1- These were the wrongly calculated take-off speeds:
    V1: 118 KIAS
    Vr: 118 KIAS
    V2: 126 KIAS

    Seriously? Had the wrong calculation delivered 40 KIAS, 40 KIAS, 50 KIAS they would also have attempted to rotate at 50???? Anybody with the slightest idea general performance of jet airliners knows that these are not speeds for a Madrid to Mexico trip. Not in the 767 (incident plane), not in a 737, not in a A380. The crew was not very experienced, but do you really need to be very experience to note it?

    2- The rear cabin crew waited until reaching 10000ft for the sterile cockpit to end to inform the flight crew that there had been strange noises and a bump during the rotation.

    Seriously? Sterile cockpit means to keep the cockpit free of any activity that is NOT related to the SAFE OPERATION of the flight. Had there been a fire they would have also waited for the sterile cockpit to be lifted?

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  • BoeingBobby
    replied
    Yawn!

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  • 3WE
    replied
    Originally posted by Evan View Post
    $$$$$$$
    Yes.

    That is part of it.

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  • Evan
    replied
    Originally posted by 3WE View Post
    ...As I keep trying to state, we are not the first people to ever think of this, and for some reason (probably a pretty darn valid reason)
    $$$$$$$

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  • 3WE
    replied
    Originally posted by Evan View Post
    Explain to me how this poses a significant risk of causing an accident.
    Um no, Evan, I will not explain it to you.

    I have no authority to move towards broad adoption of TPMSs in commercial aviation- and IMHAHPTO- aside from a freak accident as the result of a false warning, I tend to agree that it does not pose a significant risk.

    ...As I keep trying to state, we are not the first people to ever think of this, and for some reason (probably a pretty darn valid reason), TPMSs are not widely used and takeoff is a critical time where pilots do not need distractions.

    That doesn't say that it's not time to install the TPMS app from the app store to the I-Pad, but it is at least a little more complicated than typing proclamations on obscure amateur aviation forums.

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