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.
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
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 takeoffperformance
monitoring, no matter the size.
That isnt going to result in the problem beingfixed 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,
and whether the aircraft will be able toboth continue a takeoff, and stop, at v1.
It can issue an abort alert if not.
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.
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 takeoffperformance
monitoring, no matter the size.
That isnt going to result in the problem-a beingfixed quickly enough
to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr are
correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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
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.
[*] 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.
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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr are
correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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
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
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.
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 thatNot reasible to measure that during the takeoff run before V1
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.
Why not?
On 24-Jan-25 4:21 pm, 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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr are >>>>> correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, 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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr are >>>>>> correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
I assume that you are talking about some sort of automated system to
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to takeoff so
the system would be only as good as the data therefore it doesn't
completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:I assume that you are talking about some sort of automated system to
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.
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to takeoff
so the system would be only as good as the data therefore it doesn't
completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
I sent a reply to this, but I'm not seeing it. If you can't see it
either, I'll post it again.
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, 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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr are >>>>>> correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
I assume that you are talking about some sort of automated system to
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to takeoff so
the system would be only as good as the data therefore it doesn't
completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, 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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr >>>>>>> are correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
I assume that you are talking about some sort of automated system to
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to takeoff
so the system would be only as good as the data therefore it doesn't
completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy so as
not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the GPS calculated position allows the system to determine which runway the
aircraft is on (position alone may not be sufficient, where runways intersect).
The acceleration to be expected from a given thrust setting depends on
the aircraft's mass, and its airspeed. So the system waits until there
is a reliable airspeed. It then can calculate the mass from the expected thrust, the acceleration and the airspeed. The result should match the setting. If it doesn't this means that either the mass is set wrong, or
the expected thrust, based on the thrust setting, is not being achieved. Either of these aborts the takeoff.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
From the current position, the acceleration and the mass, the braking distance can be calculated [*], and from that V1. If the calculated V1
is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends on runway condition (wet, dry, etc.).
Sylvia.
On 25/1/2025 7:44 pm, Sylvia Else wrote:
On 25-Jan-25 6:19 am, Daryl wrote:My piloting experience is 5hrs training in a helicopter so not much but
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, 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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr >>>>>>>> are correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
I assume that you are talking about some sort of automated system to
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to takeoff
so the system would be only as good as the data therefore it doesn't
completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy so
as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the GPS
calculated position allows the system to determine which runway the
aircraft is on (position alone may not be sufficient, where runways
intersect).
The acceleration to be expected from a given thrust setting depends on
the aircraft's mass, and its airspeed. So the system waits until there
is a reliable airspeed. It then can calculate the mass from the
expected thrust, the acceleration and the airspeed. The result should
match the setting. If it doesn't this means that either the mass is
set wrong, or the expected thrust, based on the thrust setting, is not
being achieved. Either of these aborts the takeoff.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
-aFrom the current position, the acceleration and the mass, the braking
distance can be calculated [*], and from that V1. If the calculated V1
is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends on
runway condition (wet, dry, etc.).
Sylvia.
to me it sounds a bit complex and still open to input error to be of
much value?
Might be feasible on newer complex aircraft but retrofitting such a
system on older aircraft would most likely be very expensive and maybe
not even possible.
You didn't answer the question about self reporting, was that mentioned
in the ATSB report?
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:I assume that you are talking about some sort of automated system to
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.
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to takeoff
so the system would be only as good as the data therefore it doesn't
completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy so as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the GPS calculated position allows the system to determine which runway the aircraft is on (position alone may not be sufficient, where runways intersect).
The acceleration to be expected from a given thrust setting depends on
the aircraft's mass, and its airspeed. So the system waits until there
is a reliable airspeed. It then can calculate the mass from the expected thrust, the acceleration and the airspeed. The result should match the setting. If it doesn't this means that either the mass is set wrong, or
the expected thrust, based on the thrust setting, is not being achieved. Either of these aborts the takeoff.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
From the current position, the acceleration and the mass, the braking distance can be calculated [*], and from that V1. If the calculated V1
is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends on runway condition (wet, dry, etc.).
On 25-Jan-25 7:36 pm, Daryl wrote:
On 25/1/2025 7:44 pm, Sylvia Else wrote:
On 25-Jan-25 6:19 am, Daryl wrote:My piloting experience is 5hrs training in a helicopter so not much
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, 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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr >>>>>>>>> are correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
I assume that you are talking about some sort of automated system to
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to
takeoff so the system would be only as good as the data therefore it
doesn't completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy so
as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the
GPS calculated position allows the system to determine which runway
the aircraft is on (position alone may not be sufficient, where
runways intersect).
The acceleration to be expected from a given thrust setting depends
on the aircraft's mass, and its airspeed. So the system waits until
there is a reliable airspeed. It then can calculate the mass from the
expected thrust, the acceleration and the airspeed. The result should
match the setting. If it doesn't this means that either the mass is
set wrong, or the expected thrust, based on the thrust setting, is
not being achieved. Either of these aborts the takeoff.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
-aFrom the current position, the acceleration and the mass, the
braking distance can be calculated [*], and from that V1. If the
calculated V1 is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends
on runway condition (wet, dry, etc.).
Sylvia.
but to me it sounds a bit complex and still open to input error to be
of much value?
Might be feasible on newer complex aircraft but retrofitting such a
system on older aircraft would most likely be very expensive and maybe
not even possible.
You didn't answer the question about self reporting, was that
mentioned in the ATSB report?
I can't find a specific reference to how this came to the attention of
the ATSB. Most likely it was reported to Qantas Link by the pilots, and Qantas Link then reported it to the ATSB.
Sylvia.
On 26/1/2025 1:12 am, Sylvia Else wrote:
On 25-Jan-25 7:36 pm, Daryl wrote:
On 25/1/2025 7:44 pm, Sylvia Else wrote:I can't find a specific reference to how this came to the attention of
On 25-Jan-25 6:19 am, Daryl wrote:My piloting experience is 5hrs training in a helicopter so not much
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, 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.
I assume that you are talking about some sort of automated system to >>>>> alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to
takeoff so the system would be only as good as the data therefore it >>>>> doesn't completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy so >>>> as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the
GPS calculated position allows the system to determine which runway
the aircraft is on (position alone may not be sufficient, where
runways intersect).
The acceleration to be expected from a given thrust setting depends
on the aircraft's mass, and its airspeed. So the system waits until
there is a reliable airspeed. It then can calculate the mass from the >>>> expected thrust, the acceleration and the airspeed. The result should >>>> match the setting. If it doesn't this means that either the mass is
set wrong, or the expected thrust, based on the thrust setting, is
not being achieved. Either of these aborts the takeoff.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
From the current position, the acceleration and the mass, the
braking distance can be calculated [*], and from that V1. If the
calculated V1 is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends
on runway condition (wet, dry, etc.).
Sylvia.
but to me it sounds a bit complex and still open to input error to be
of much value?
Might be feasible on newer complex aircraft but retrofitting such a
system on older aircraft would most likely be very expensive and maybe >>> not even possible.
You didn't answer the question about self reporting, was that
mentioned in the ATSB report?
the ATSB. Most likely it was reported to Qantas Link by the pilots, and
Qantas Link then reported it to the ATSB.
Would it be mandatory for the pilots to report to the airline or just
good practice?
If the airlines culture encouraged them to report without consequence
then its a good safety measure, maybe that's why airlines in Australia
have such a good safety record?
On Sat, 25 Jan 2025 19:44:58 +1100, Sylvia Else <sylvia@email.invalid> wrote:
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:-aI assume that you are talking about some sort of automated system to
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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough
informationto-a determine whether the crew calculated v1 and vr >>>>>>>> are correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
alert pilots of a configuration error?
If so wouldn't that rely on data input by the pilots prior to takeoff
so the system would be only as good as the data therefore it doesn't
completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy so
as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the GPS
calculated position allows the system to determine which runway the
aircraft is on (position alone may not be sufficient, where runways
intersect).
The acceleration to be expected from a given thrust setting depends on
the aircraft's mass, and its airspeed. So the system waits until there
is a reliable airspeed. It then can calculate the mass from the
expected thrust, the acceleration and the airspeed. The result should
match the setting. If it doesn't this means that either the mass is
set wrong, or the expected thrust, based on the thrust setting, is not
being achieved. Either of these aborts the takeoff.
Not possible to MEASURE that the flaps haven't been set correctly
before V1 because you can only measure the effect of that after VR
when rotation has been attempted and it can measure that it doesnt
see the weight leaving the wheels in the way that it should have,
And given that it is already past V1, no way to abort by then
Makes a lot more sense to enter all the paramaters that will
be used like thrust settings and flaps etc and them before
takeoff power can be applied, check that that has been done.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
Too late by then, its already past V1 so it can't be aborted
-aFrom the current position, the acceleration and the mass, the braking
distance can be calculated [*], and from that V1. If the calculated V1
is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends on
runway condition (wet, dry, etc.).
And can't be measured during the takeoff run
On 25-Jan-25 11:21 pm, Rod Speed wrote:
On Sat, 25 Jan 2025 19:44:58 +1100, Sylvia Else <sylvia@email.invalid>
wrote:
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:I assume that you are talking about some sort of automated system to >>>> alert pilots of a configuration error?
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.
If so wouldn't that rely on data input by the pilots prior to takeoff >>>> so the system would be only as good as the data therefore it doesn't >>>> completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy so
as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the GPS >>> calculated position allows the system to determine which runway the
aircraft is on (position alone may not be sufficient, where runways
intersect).
The acceleration to be expected from a given thrust setting depends on >>> the aircraft's mass, and its airspeed. So the system waits until there >>> is a reliable airspeed. It then can calculate the mass from the
expected thrust, the acceleration and the airspeed. The result should
match the setting. If it doesn't this means that either the mass is
set wrong, or the expected thrust, based on the thrust setting, is not >>> being achieved. Either of these aborts the takeoff.
Not possible to MEASURE that the flaps haven't been set correctly
before V1 because you can only measure the effect of that after VR
when rotation has been attempted and it can measure that it doesnt
see the weight leaving the wheels in the way that it should have,
The issue is only whether the aircraft will take off at the set Vr,
which is a function of the flap setting, and aircraft mass.
This is something that can be determined from the aircraft'sflight performance data - the same data that the crew use.
If the flaps are not at the position set for them, that'ssomething that should already have been alerted.
And given that it is already past V1, no way to abort by then
Makes a lot more sense to enter all the paramaters that will
be used like thrust settings and flaps etc and them before
takeoff power can be applied, check that that has been done.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
Too late by then, its already past V1 so it can't be aborted
Why is it already past v1?
From the current position, the acceleration and the mass, the braking >>> distance can be calculated [*], and from that V1. If the calculated V1 >>> is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends on >>> runway condition (wet, dry, etc.).
And can't be measured during the takeoff run
No, it cannot, hence the uncertainty. But if the system assumes good braking, and the calculated v1 is less than the set v1, then the set v1
is wrong regardless of the actual braking conditions.
On Sun, 26 Jan 2025 19:29:10 +1100, Sylvia Else <sylvia@email.invalid> wrote:
On 25-Jan-25 11:21 pm, Rod Speed wrote:
On Sat, 25 Jan 2025 19:44:58 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:-aI assume that you are talking about some sort of automated system >>>>> to alert pilots of a configuration error?
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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough >>>>>>>>>> informationto-a determine whether the crew calculated v1 and vr >>>>>>>>>> are correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
If so wouldn't that rely on data input by the pilots prior to
takeoff so the system would be only as good as the data therefore
it doesn't completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap,
thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy
so as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the
GPS calculated position allows the system to determine which runway
the aircraft is on (position alone may not be sufficient, where
runways intersect).
The acceleration to be expected from a given thrust setting depends
on the aircraft's mass, and its airspeed. So the system waits until
there is a reliable airspeed. It then can calculate the mass from
the expected thrust, the acceleration and the airspeed. The result
should match the setting. If it doesn't this means that either the
mass is set wrong, or the expected thrust, based on the thrust
setting, is not being achieved. Either of these aborts the takeoff.
-aNot possible to MEASURE that the flaps haven't been set correctly
before V1 because you can only measure the effect of that after VR
when rotation has been attempted and it can measure that it doesnt
see the weight leaving the wheels in the way that it should have,
The issue is only whether the aircraft will take off at the set Vr,
which is a function of the flap setting, and aircraft mass.
Yes
This is-a something that can be determined from the aircraft'sflight
performance-a data - the same data that the crew use.
That isnt MEASUREMEMT of the plane's performance during the takeoff run
If the flaps are not at the position set for them, that'ssomething
that-a should already have been alerted.
What I said right from the start
-aAnd given that it is already past V1, no way to abort by then
-aMakes a lot more sense to enter all the paramaters that will
be used like thrust settings and flaps etc and them before
takeoff power can be applied, check that that has been done.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
-aToo late by then, its already past V1 so it can't be aborted
Why is it already past v1?
Because that's the only time you know that it can't rotate at the time
that it should have been able to, because the flap setting is wrong.
-aFrom the current position, the acceleration and the mass, the
braking distance can be calculated [*], and from that V1. If the
calculated V1 is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends
on runway condition (wet, dry, etc.).
-aAnd can't be measured during the takeoff run
No, it cannot, hence the uncertainty. But if the system assumes good
braking, and the calculated v1 is less than the set v1, then the set
v1 is wrong regardless of the actual braking conditions.
So its too late to abort the takeoff
So the only thing that makes any sense is to check that the pilots
have actually set stuff like flaps and takeoff power they way they
have calculated needs to be BEFORE the takeoff can happen.
No point in measuring anything once the takeoff run has started except with the engine performance and that isnt what is being discussed with this incident.
On 26-Jan-25 5:14 pm, Rod Speed wrote:
On Sun, 26 Jan 2025 19:29:10 +1100, Sylvia Else <sylvia@email.invalid>
wrote:
On 25-Jan-25 11:21 pm, Rod Speed wrote:Yes
On Sat, 25 Jan 2025 19:44:58 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:If so wouldn't that rely on data input by the pilots prior to
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. >>>>>> I assume that you are talking about some sort of automated system >>>>>> to alert pilots of a configuration error?
takeoff so the system would be only as good as the data therefore >>>>>> it doesn't completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for flap, >>>>> thrust, mass, V1 and Vr. None of these is assumed to be correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy >>>>> so as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the >>>>> GPS calculated position allows the system to determine which runway >>>>> the aircraft is on (position alone may not be sufficient, where
runways intersect).
The acceleration to be expected from a given thrust setting depends >>>>> on the aircraft's mass, and its airspeed. So the system waits until >>>>> there is a reliable airspeed. It then can calculate the mass from
the expected thrust, the acceleration and the airspeed. The result >>>>> should match the setting. If it doesn't this means that either the >>>>> mass is set wrong, or the expected thrust, based on the thrust
setting, is not being achieved. Either of these aborts the takeoff.
Not possible to MEASURE that the flaps haven't been set correctly
before V1 because you can only measure the effect of that after VR
when rotation has been attempted and it can measure that it doesnt
see the weight leaving the wheels in the way that it should have,
The issue is only whether the aircraft will take off at the set Vr,
which is a function of the flap setting, and aircraft mass.
This is something that can be determined from the aircraft'sflightThat isnt MEASUREMEMT of the plane's performance during the takeoff run
performance data - the same data that the crew use.
If the flaps are not at the position set for them, that'ssomethingWhat I said right from the start
that should already have been alerted.
Because that's the only time you know that it can't rotate at the timeAnd given that it is already past V1, no way to abort by then
Makes a lot more sense to enter all the paramaters that will
be used like thrust settings and flaps etc and them before
takeoff power can be applied, check that that has been done.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
Too late by then, its already past V1 so it can't be aborted
Why is it already past v1?
that it should have been able to, because the flap setting is wrong.
So its too late to abort the takeoffFrom the current position, the acceleration and the mass, the
braking distance can be calculated [*], and from that V1. If the
calculated V1 is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance depends >>>>> on runway condition (wet, dry, etc.).
And can't be measured during the takeoff run
No, it cannot, hence the uncertainty. But if the system assumes good
braking, and the calculated v1 is less than the set v1, then the set
v1 is wrong regardless of the actual braking conditions.
So the only thing that makes any sense is to check that the pilots
have actually set stuff like flaps and takeoff power they way they
have calculated needs to be BEFORE the takeoff can happen.
No point in measuring anything once the takeoff run has started except
with
the engine performance and that isnt what is being discussed with this
incident.
Do you agree that, knowing only the aerodynamic properties of the air-frame, the actual flap position and the actual takeoff weight, the correct Vr can be calculated?
If not, what else is needed?
On Mon, 27 Jan 2025 15:17:39 +1100, Sylvia Else <sylvia@email.invalid> wrote:
On 26-Jan-25 5:14 pm, Rod Speed wrote:
On Sun, 26 Jan 2025 19:29:10 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 11:21 pm, Rod Speed wrote:-aYes
On Sat, 25 Jan 2025 19:44:58 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:system to alert pilots of a configuration error?
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-a monitoring, no matter the size.
That isnt going to result in the problem-a being
fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough >>>>>>>>>>>> informationto-a determine whether the crew calculated v1 and >>>>>>>>>>>> vr are correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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. >>>>>>> -aI assume that you are talking about some sort of automated
If so wouldn't that rely on data input by the pilots prior to
takeoff so the system would be only as good as the data therefore >>>>>>> it doesn't completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for
flap, thrust, mass, V1 and Vr. None of these is assumed to be
correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy >>>>>> so as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the >>>>>> GPS calculated position allows the system to determine which
runway the aircraft is on (position alone may not be sufficient,
where runways intersect).
The acceleration to be expected from a given thrust setting
depends on the aircraft's mass, and its airspeed. So the system
waits until there is a reliable airspeed. It then can calculate
the mass from the expected thrust, the acceleration and the
airspeed. The result should match the setting. If it doesn't this >>>>>> means that either the mass is set wrong, or the expected thrust,
based on the thrust setting, is not being achieved. Either of
these aborts the takeoff.
-aNot possible to MEASURE that the flaps haven't been set correctly
before V1 because you can only measure the effect of that after VR
when rotation has been attempted and it can measure that it doesnt
see the weight leaving the wheels in the way that it should have,
The issue is only whether the aircraft will take off at the set Vr,
which is a function of the flap setting, and aircraft mass.
This is-a something that can be determined from the aircraft'sflight-aThat isnt MEASUREMEMT of the plane's performance during the takeoff run >>>
performance-a data - the same data that the crew use.
If the flaps are not at the position set for them, that'ssomething-aWhat I said right from the start
that-a should already have been alerted.
-aBecause that's the only time you know that it can't rotate at the time >>> that it should have been able to, because the flap setting is wrong.-aAnd given that it is already past V1, no way to abort by then
-aMakes a lot more sense to enter all the paramaters that will
be used like thrust settings and flaps etc and them before
takeoff power can be applied, check that that has been done.
Vr can now be calculated based the mass and flap setting. If the
calculated Vr differs from the set Vr, this aborts the takeoff.
-aToo late by then, its already past V1 so it can't be aborted
Why is it already past v1?
-aSo its too late to abort the takeoff-aFrom the current position, the acceleration and the mass, the
braking distance can be calculated [*], and from that V1. If the
calculated V1 is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance
depends on runway condition (wet, dry, etc.).
-aAnd can't be measured during the takeoff run
No, it cannot, hence the uncertainty. But if the system assumes good
braking, and the calculated v1 is less than the set v1, then the set
v1 is wrong regardless of the actual braking conditions.
-aSo the only thing that makes any sense is to check that the pilots
have actually set stuff like flaps and takeoff power they way they
have calculated needs to be BEFORE the takeoff can happen.
-aNo point in measuring anything once the takeoff run has started
except with
the engine performance and that isnt what is being discussed with
this incident.
Do you agree that, knowing only the aerodynamic properties of the
air-frame, the actual flap position and the actual takeoff weight, the
correct Vr can be calculated?
Nope, you also need to know the temperature, wind speed and
direction and there is no way to measure the actual takeoff weight
On 27-Jan-25 4:52 pm, Rod Speed wrote:
On Mon, 27 Jan 2025 15:17:39 +1100, Sylvia Else <sylvia@email.invalid>
wrote:
On 26-Jan-25 5:14 pm, Rod Speed wrote:
On Sun, 26 Jan 2025 19:29:10 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 11:21 pm, Rod Speed wrote:Yes
On Sat, 25 Jan 2025 19:44:58 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:system to alert pilots of a configuration error?
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. >>>>>>>> I assume that you are talking about some sort of automated
If so wouldn't that rely on data input by the pilots prior to >>>>>>>> takeoff so the system would be only as good as the data therefore >>>>>>>> it doesn't completely eliminate the chances of an error?
In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for
flap, thrust, mass, V1 and Vr. None of these is assumed to be
correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of discrepancy >>>>>>> so as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with the >>>>>>> GPS calculated position allows the system to determine which
runway the aircraft is on (position alone may not be sufficient, >>>>>>> where runways intersect).
The acceleration to be expected from a given thrust setting
depends on the aircraft's mass, and its airspeed. So the system >>>>>>> waits until there is a reliable airspeed. It then can calculate >>>>>>> the mass from the expected thrust, the acceleration and the
airspeed. The result should match the setting. If it doesn't this >>>>>>> means that either the mass is set wrong, or the expected thrust, >>>>>>> based on the thrust setting, is not being achieved. Either of
these aborts the takeoff.
Not possible to MEASURE that the flaps haven't been set correctly >>>>>> before V1 because you can only measure the effect of that after VR >>>>>> when rotation has been attempted and it can measure that it doesnt >>>>>> see the weight leaving the wheels in the way that it should have,
The issue is only whether the aircraft will take off at the set Vr, >>>>> which is a function of the flap setting, and aircraft mass.
This is something that can be determined from the aircraft'sflight >>>>> performance data - the same data that the crew use.That isnt MEASUREMEMT of the plane's performance during the takeoff >>>> run
If the flaps are not at the position set for them, that'ssomething >>>>> that should already have been alerted.What I said right from the start
Because that's the only time you know that it can't rotate at theAnd given that it is already past V1, no way to abort by then
Makes a lot more sense to enter all the paramaters that will
be used like thrust settings and flaps etc and them before
takeoff power can be applied, check that that has been done.
Vr can now be calculated based the mass and flap setting. If the >>>>>>> calculated Vr differs from the set Vr, this aborts the takeoff.
Too late by then, its already past V1 so it can't be aborted
Why is it already past v1?
time
that it should have been able to, because the flap setting is wrong.
So its too late to abort the takeoffFrom the current position, the acceleration and the mass, the >>>>>>> braking distance can be calculated [*], and from that V1. If the >>>>>>> calculated V1 is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance
depends on runway condition (wet, dry, etc.).
And can't be measured during the takeoff run
No, it cannot, hence the uncertainty. But if the system assumes good >>>>> braking, and the calculated v1 is less than the set v1, then the set >>>>> v1 is wrong regardless of the actual braking conditions.
So the only thing that makes any sense is to check that the pilots
have actually set stuff like flaps and takeoff power they way they
have calculated needs to be BEFORE the takeoff can happen.
No point in measuring anything once the takeoff run has started
except with
the engine performance and that isnt what is being discussed with
this incident.
Do you agree that, knowing only the aerodynamic properties of the
air-frame, the actual flap position and the actual takeoff weight, the >>> correct Vr can be calculated?
Nope, you also need to know the temperature, wind speed and
direction and there is no way to measure the actual takeoff weight
Vr is an indicated airspeed, so why do you need to know wind-speed or temperature?
Do you agree that takeoff weight can be calculated from thrust and acceleration?
On Mon, 27 Jan 2025 19:56:36 +1100, Sylvia Else <sylvia@email.invalid> wrote:
On 27-Jan-25 4:52 pm, Rod Speed wrote:
On Mon, 27 Jan 2025 15:17:39 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 26-Jan-25 5:14 pm, Rod Speed wrote:
On Sun, 26 Jan 2025 19:29:10 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 11:21 pm, Rod Speed wrote:-aYes
On Sat, 25 Jan 2025 19:44:58 +1100, Sylvia Else
<sylvia@email.invalid> wrote:
On 25-Jan-25 6:19 am, Daryl wrote:
On 25/1/2025 12:59 am, Sylvia Else wrote:
On 24-Jan-25 4:21 pm, Rod Speed wrote:-aI assume that you are talking about some sort of automated >>>>>>>>> system to alert pilots of a configuration error?
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-a monitoring, no matter the size.
That isnt going to result in the problem-a being >>>>>>>>>>>>>>> fixed quickly enough-a to-a stop an accident
Well before an abort becomes risky, the system has enough >>>>>>>>>>>>>> informationto-a determine whether the crew calculated v1 >>>>>>>>>>>>>> and vr are correct,
Bullshit with that incorrect flaps setting.
and whether-a the aircraft will be able-a 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.
-aIt 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.
-aSee 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.
If so wouldn't that rely on data input by the pilots prior to >>>>>>>>> takeoff so the system would be only as good as the data
therefore it doesn't completely eliminate the chances of an error? >>>>>>>>> In this incident did the pilots self report?
If they didn't why would the ATSB investigate?
My thinking is that the system has access to the settings for >>>>>>>> flap, thrust, mass, V1 and Vr. None of these is assumed to be >>>>>>>> correct.
Also access to GPS and airspeed.
In the following, the system would allow some level of
discrepancy so as not to cause unnecessary aborts.
Once the aircraft is accelerating, its direction together with >>>>>>>> the GPS calculated position allows the system to determine which >>>>>>>> runway the aircraft is on (position alone may not be sufficient, >>>>>>>> where runways intersect).
The acceleration to be expected from a given thrust setting
depends on the aircraft's mass, and its airspeed. So the system >>>>>>>> waits until there is a reliable airspeed. It then can calculate >>>>>>>> the mass from the expected thrust, the acceleration and the
airspeed. The result should match the setting. If it doesn't
this means that either the mass is set wrong, or the expected >>>>>>>> thrust, based on the thrust setting, is not being achieved.
Either of these aborts the takeoff.
-aNot possible to MEASURE that the flaps haven't been set correctly >>>>>>> before V1 because you can only measure the effect of that after VR >>>>>>> when rotation has been attempted and it can measure that it doesnt >>>>>>> see the weight leaving the wheels in the way that it should have,
The issue is only whether the aircraft will take off at the set
Vr, which is a function of the flap setting, and aircraft mass.
This is-a something that can be determined from thetakeoff run
aircraft'sflight performance-a data - the same data that the crew use. >>>>> -aThat isnt MEASUREMEMT of the plane's performance during the
If the flaps are not at the position set for them, that'ssomething >>>>>> that-a should already have been alerted.-aWhat I said right from the start
-aBecause that's the only time you know that it can't rotate at the >>>>> time-aAnd given that it is already past V1, no way to abort by then
-aMakes a lot more sense to enter all the paramaters that will
be used like thrust settings and flaps etc and them before
takeoff power can be applied, check that that has been done.
Vr can now be calculated based the mass and flap setting. If the >>>>>>>> calculated Vr differs from the set Vr, this aborts the takeoff.
-aToo late by then, its already past V1 so it can't be aborted
Why is it already past v1?
that it should have been able to, because the flap setting is wrong. >>>>>
-aSo its too late to abort the takeoff-aFrom the current position, the acceleration and the mass, the >>>>>>>> braking distance can be calculated [*], and from that V1. If the >>>>>>>> calculated V1 is lower than the set V1, then abort take off.
[*] This is one area of uncertainty, since braking distance
depends on runway condition (wet, dry, etc.).
-aAnd can't be measured during the takeoff run
No, it cannot, hence the uncertainty. But if the system assumes
good braking, and the calculated v1 is less than the set v1, then >>>>>> the set v1 is wrong regardless of the actual braking conditions.
-aSo the only thing that makes any sense is to check that the pilots >>>>> have actually set stuff like flaps and takeoff power they way they
have calculated needs to be BEFORE the takeoff can happen.
-aNo point in measuring anything once the takeoff run has started
except with
the engine performance and that isnt what is being discussed with
this incident.
Do you agree that, knowing only the aerodynamic properties of the
air-frame, the actual flap position and the actual takeoff weight,
the correct Vr can be calculated?
-aNope, you also need to know the temperature, wind speed and
direction and there is no way to measure the actual takeoff weight
Vr is an indicated airspeed, so why do you need to know wind-speed or
temperature?
You said CALCULATED. Yes you need both to CALCULATE VR.
so you can attempt to rotate when the indicated air speed reaches
the value that you have calculated that rotation should be attemped.
Do you agree that takeoff weight can be calculated from thrust and
acceleration?
Not when you can't be sure that the measured thrust has been
measured accurately particularly when the engines are still
spinning up after TOGA has been applied, and acceleration
is also variable, particularly when the wind direction and
speed is changing substantially during the takeoff run
Still makes a lot more sense to check that stuff like flaps,
engine power, bleed air bypass has actually been set the
way the pilots have calculated needs to be set before they
are allowed to actually takeoff and that is MUCH easier to
do and doesnt require expensive extra equipment in the
plane and allows the pilots to check that the checking
system hasnt got it wrong and doesnt need a risky
attempt to abort the takeoff before V1
Your approach makes no sense at all except to actually
measure that the acceleration that should be happening
actually is happening during the takeoff run because
there is some problem with at least one engine etc. And
isnt even possible with the flap setting because you can
only measure that the expected lift is being seen once an
attempt at rotation has been attempted because its past
VR and by then its too late to abort the takeoff because
the plane is already past V1
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