Re: Dash-8 incorrect takeoff configuration.

From	"Rod Speed" <rod.speed.aaa@gmail.com>
Newsgroups	aus.aviation
Subject	Re: Dash-8 incorrect takeoff configuration.
Date	2025-01-25 03:46 +1100
Message-ID	<op.20v0u0ikbyq249@pvr2.lan> (permalink)
References	(2 earlier) <lve051Fl5i1U1@mid.individual.net> <op.20tk2vlxbyq249@pvr2.lan> <lvgpdlF3t5nU2@mid.individual.net> <op.20vdh9dzbyq249@pvr2.lan> <lvhkmqF8lmsU1@mid.individual.net>

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Sylvia Else <sylvia@email.invalid> wrote
> Rod Speed wrote
>> Sylvia Else <sylvia@email.invalid> wrote
>>> Rod Speed wrote
>>>> Sylvia Else <sylvia@email.invalid> wrote
>>>>> Rod Speed wrote
>>>>>> Sylvia Else <sylvia@email.invalid> wrote

>>>>>>> https://www.atsb.gov.au/publications/investigation_reports/2025/report/ao-2024-038

>>>>>>> It's time all public transport aircraft had takeoff
>>>>>>> performance  monitoring, no matter the size.

>>>>>> That isnt going to result in the problem  being
>>>>>> fixed quickly enough  to  stop an accident

>>>>> Well before an abort becomes risky, the system has enough  
>>>>> informationto  determine whether the crew calculated v1 and vr are  
>>>>> correct,

>>>> Bullshit with that incorrect flaps setting.

>>>>> and whether  the aircraft will be able  toboth continue a takeoff,  
>>>>> and stop, at v1.

>>>> Bullshit with that incorrect flaps setting, let alone
>>>> tell the pilots that the flaps setting is wrong.

>>>>  It would make much more sense to compare the
>>>> actual settings with that has been entered at the
>>>> preflight config calculations and tell the pilots
>>>> that they have not set what was required with
>>>> flaps and boost etc before they actually applied
>>>> takeoff power and not allow takeoff power to be
>>>> applied before those were set correctly.

>>>>> It can issue an abort alert if not.

>>>>  See above

>>>>> This covers at least miscalculated v1, miscalculated vr, wrong  
>>>>> thrust settings, wrong flap settings, starting from the wrong  
>>>>> intersection, takeoff from the wrong runway, and no doubt others  
>>>>> that I haven't even thought of.

>>>> It would be stupid to try to measure that while taking off
>>>> instead of doing that before takeoff power is applied

>>>> Yes, there is also a different problem with the engines
>>>> not being able to deliver the power they were assumed
>>>> to be able to deliver the power they were supposed to
>>>> be able to deliver in the preflight calculations, but that
>>>> was not the case in the incident being discussed and
>>>> it would be much easier to discover than much earlier
>>>> in the takeoff run than V1 or VR

>>> The question the system needs to ask is "In the current configuration,  
>>> with the measured acceleration [*], current airspeed, and current  
>>> position on the current runway, can the aircraft reach the specified  
>>> V1 at a point where it can continue the takeoff or abort, and will it  
>>> be able to rotate at the specified Vr.

>>  The problem with that approach is that is far too late
>> during the takeoff run to be doing that by measurement
>> when its much too late for the pilots to be fixing what
>> the problem is, particularly when the engines arent
>> actually performing the way they were meant to when
>> the prefight calculations were done

> There would be no expectation that the pilots would fix it. The idea is  
> to abort the takeoff while that can still be done safely.

No way to detect the wrong flap setting by measurement
of the aircraft performance before V1, that is only going
to be possible once its past VR and the pilots discover
that the plane won't leave the runway when it is sposed to.

Even if you are attempting to determine if the engines are
performing properly and something in the engines has
failed to deliver the thrust they should be delivering or
TOGA has not been commanded, there is no way to
measure that the plane has not reached V1 by the time
it was supposed to..

>>  Like I said, it makes much more sense to check that
>> the pilots have set what they have caculated nees to
>> be set before takeoff power is allowed to be applied

>>> [*] This also gives a reasonable estimate of the mass, assuming that  
>>> the engine thrust is as commanded, or the engine thrust assuming that  
>>> the mass is as configured, and allows an abort alert if the mass,  
>>> acceleration, and thrust are not consistent with each other.
>>  Not reasible to measure that during the takeoff run before V1

> Why not?

See above

Thread

Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-21 13:28 +0800
  Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-23 04:21 +1100
    Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-23 12:50 +0800
      Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-23 20:09 +1100
        Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-24 14:14 +0800
          Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-24 19:21 +1100
            Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-24 21:59 +0800
              Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-25 03:46 +1100
              Re: Dash-8 incorrect takeoff configuration. Daryl <dwalford@westpine.com.au> - 2025-01-25 09:19 +1100
                Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-25 13:17 +0800
                Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-25 19:34 +1100
                Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-25 16:44 +0800
                Re: Dash-8 incorrect takeoff configuration. Daryl <dwalford@westpine.com.au> - 2025-01-25 22:36 +1100
                Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-25 22:12 +0800
                Re: Dash-8 incorrect takeoff configuration. Daryl <dwalford@westpine.com.au> - 2025-01-26 09:36 +1100
                Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-26 10:07 +1100
                Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-26 02:21 +1100
                Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-26 16:29 +0800
                Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-26 20:14 +1100
                Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-27 12:17 +0800
                Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-27 19:52 +1100
                Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-27 16:56 +0800
                Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-28 04:33 +1100
                Re: Dash-8 incorrect takeoff configuration. Sylvia Else <sylvia@email.invalid> - 2025-01-28 11:52 +0800
                Re: Dash-8 incorrect takeoff configuration. "Rod Speed" <rod.speed.aaa@gmail.com> - 2025-01-28 15:57 +1100

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