EK407 Tailstrike @ ML
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Flightdeck distractions
Interesting article from Flight International about Flightdeck distractions.
Distractions frequently cause flapless take-offs, NASA reveals
AA
Distractions frequently cause flapless take-offs, NASA reveals
AA
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In terms of accel vs. time checks, there are a couple of things here:
1. Accel vs. time is going to be simply a function of excess thrust over weight, surely. It will not indicate where you are, or should be/have been on the runway. Unfortunately, a position on the runway is what we need to know -and is effectively what V1 gives us (assuming correct acceleration), based on ambient conditions.
The question then becomes "When we get to V1 will we be at the correct spot?' Waiting until V1 to see the result will only tell you whether things are about to go badly, or not, so:
2. We need a distance to go vs. speed check, again based on ambient conditions, at a convenient point prior to V1. Unfortunately, current wisdom has seen distance to run markers all but disappear. Bugger-they were quite useful for landing as well..
Perhaps there is a possibility of an acceleration rate check, based on ambient conditions and groundspeed, driven by GPS/RAAS and triggered when the TO/GA switches are pushed on departure? Something for the boffins...
As for the 777, yes, the airspeed trend vector is very useful, though nothing is formalised regarding its use on takeoff, other than as a windshear indicator, or did I miss something? As others have said here, it's a good crosscheck, nonetheless.
1. Accel vs. time is going to be simply a function of excess thrust over weight, surely. It will not indicate where you are, or should be/have been on the runway. Unfortunately, a position on the runway is what we need to know -and is effectively what V1 gives us (assuming correct acceleration), based on ambient conditions.
The question then becomes "When we get to V1 will we be at the correct spot?' Waiting until V1 to see the result will only tell you whether things are about to go badly, or not, so:
2. We need a distance to go vs. speed check, again based on ambient conditions, at a convenient point prior to V1. Unfortunately, current wisdom has seen distance to run markers all but disappear. Bugger-they were quite useful for landing as well..
Perhaps there is a possibility of an acceleration rate check, based on ambient conditions and groundspeed, driven by GPS/RAAS and triggered when the TO/GA switches are pushed on departure? Something for the boffins...
As for the 777, yes, the airspeed trend vector is very useful, though nothing is formalised regarding its use on takeoff, other than as a windshear indicator, or did I miss something? As others have said here, it's a good crosscheck, nonetheless.
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Perhaps there is a possibility of an acceleration rate check, based on ambient conditions and groundspeed, driven by GPS/RAAS and triggered when the TO/GA switches are pushed on departure? Something for the boffins...
Now that might work, but I go back to a point I made earlier - it would still have to a calculated point based on inputting the same data, hence subject to the same error.
Would guard against P1 malfunctions resulting in lower than indicated thrust though. EG The 737 in Nauru or the Potomac crash.
Nice one centurian!
We used to do time check to 80kts when flying Hercs off an unimproved strip. The NAV would start a stopwatch at the beginning of the takeoff roll and at eighty knots either say CONTINUE or STOP depending on the time taken. The timing was, of course, worked out well before the take off started and was usually around 12 seconds dependent on all the usual variables.
It worked well until you rolled into a boggy spot at 90kts!!
I can't see why something similar could not be done for RPT ops.
Regards,
BH.
It worked well until you rolled into a boggy spot at 90kts!!
I can't see why something similar could not be done for RPT ops.
Regards,
BH.
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NO LAND 3 has the answer if you're operating EFIS with speed trend vector.
Correct! And that's because the speed trend vector will usually show predicted airspeed in 10 seconds based on current acceleration! OK, it may vary from type to type, but normally at heavy weights and at about V1, an aircraft is travelling at about 200 to 300 ft per second, so it's therefore accelerating at 3 to 6 knots per second.
Therefore, if the speed trend vector is showing (about) 30 kts predicted speed increase, then acceleration is probably OK and about 3 kts/second.
Remember though, that the above is an 'approximation' only, and to be totally accurate you'd need to get SPECIFIC figures for the type that you operate. However, like all 'rules of thumb', the 'approximation' is probably fairly accurate in practical terms for the purpose of determining whether take-off is 'normal'!
No need for a speed / time check on 777 as ASI has a speed trend vector incorporated in its display. Effectively it is an obvious indicator of your level of acceleration during takeoff. On 777 it will usually extend 30 knots.
Therefore, if the speed trend vector is showing (about) 30 kts predicted speed increase, then acceleration is probably OK and about 3 kts/second.
Remember though, that the above is an 'approximation' only, and to be totally accurate you'd need to get SPECIFIC figures for the type that you operate. However, like all 'rules of thumb', the 'approximation' is probably fairly accurate in practical terms for the purpose of determining whether take-off is 'normal'!
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Folks
WRT integratin' the augment crew with the operatin' crew there's a lotta high spirited barkin goin' on but the fact remains that the A345 is a two person flight deck.
The SOPs taken from FCOM 3 make no reference whatsoever to CM3 or CM4, there is only a CM1 and a CM2. CM1 and CM2 are further allocated duties by reference to wether 'er not they are PF or PNF. Period. This is the way the manufacturer certified the aircraft and the regulators agreed.
The FOM, Ch 14 has some interstin' stuff regarding this and you kin bet that from AAR down they'll all be havin' a good study of it. Fer reasons of corporate confidentiality I won't be referin' to chapter 'n verse, nor will I publish it on this here forum. Suffice to say it's a document that like most of what this company writes give one more than enough rope ta let ya hang yerself with. It's airy fairy 'nuff to screw somebody over perty good, but it don't specifically define responsibilities an' it don't take in ta account what might be happenin' when the engineer is in the centre jumpseat completing the tech log with the fuel figgers or what might be gettin' handled in the cabin on behalf a the opertin' crew by one of the augmenters... say chasin' down stuff fer the CRC or gettin' the walk around done er whatever. It's a pretty grey area.
As the poet says: I ain't so wise as those lawyer guys... but I reckin' that the augmenters got a pertty good case for being let alone here.
That's ma two bits worth
WRT integratin' the augment crew with the operatin' crew there's a lotta high spirited barkin goin' on but the fact remains that the A345 is a two person flight deck.
The SOPs taken from FCOM 3 make no reference whatsoever to CM3 or CM4, there is only a CM1 and a CM2. CM1 and CM2 are further allocated duties by reference to wether 'er not they are PF or PNF. Period. This is the way the manufacturer certified the aircraft and the regulators agreed.
The FOM, Ch 14 has some interstin' stuff regarding this and you kin bet that from AAR down they'll all be havin' a good study of it. Fer reasons of corporate confidentiality I won't be referin' to chapter 'n verse, nor will I publish it on this here forum. Suffice to say it's a document that like most of what this company writes give one more than enough rope ta let ya hang yerself with. It's airy fairy 'nuff to screw somebody over perty good, but it don't specifically define responsibilities an' it don't take in ta account what might be happenin' when the engineer is in the centre jumpseat completing the tech log with the fuel figgers or what might be gettin' handled in the cabin on behalf a the opertin' crew by one of the augmenters... say chasin' down stuff fer the CRC or gettin' the walk around done er whatever. It's a pretty grey area.
As the poet says: I ain't so wise as those lawyer guys... but I reckin' that the augmenters got a pertty good case for being let alone here.
That's ma two bits worth
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Originally Posted by Pedota
Different aircraft and in test configuration, but interesting video nevertheless - Airbus A380 Tailstrike 1 - Video
Airbus A380 Tail Strike Test
Originally Posted by Capt Groper
And if they rejected even more interesting?
YouTube - Airbus A340-600 Rejected Take Off
YouTube - Airbus A340-600 Rejected Take Off
This video contains an audio track that has not been authorized by WMG. The audio has been disabled.
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Some more comment on what happened :
Airbus A380 Tail Strike Test
Unfortunately or ... fortunately :
Airbus A380 Tail Strike Test
Unfortunately or ... fortunately :
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The Velocity Vector is not Enough
I have to admit this accident/incident bothers me tremendously as I have thought about this issue of performance assessment on the takeoff roll for some time.
The velocity vector is a useful "secondary tool" but until the specific performance specifications using the V.V. are documented and mandated by the manufacturer as a check item on takeoff roll, to my mind its' use is "vague" at best. In fact, to my mind it is only slightly better than the "seat of the pants" judgment many experienced Captains currently use to judge the rate of acceleration on a given takeoff roll on a given day.
The V. V. is based the aircraft's computed future speed based upon a current rate of change of acceleration over a given time frame projected forward ("XX speed" will be achieved in "XX time" projected forward based upon current the current rate of acceleration).
This vector is totally dependent upon the performance data criteria selected by the crew in the flight management computers given the actual a/c weight and current runway length, field elevation and airfield wx (temp, wind and QNH).
Case in point:
If I were to take off at MTOW in any given aircraft (A-319 through to A-380 or Boeing equivalent up to 747-400) on a 20,000' runway at sea level at ISA wx conditions, you would expect a max flex t/o (irrespective of weight given the runway length) and a minimal "benign/subdued/non-aggressive/etc?" velocity vector displayed on the PFD during the take off roll through 100 kts given the conditions.
Take that same a/c and put it on an 8000' runway at 6000' above sea level and the velocity vector for the same given weight on that runway would be considerable different. How much V.V. on the PFD is right at that weight on that runway length at that temp at that elevation on that day? How much is "not enough"?
Under a different scenario, what if you take the same a/c on the same day at a "simple airport" (long runway, near sea level, normal temps, etc) and make a gross input error (due to crew fatigue/distraction/etc) in the computer inputed ZFW or max TOW data to calculate the performance figures?
Unless experience tells you to expect that based upon the given aircraft type, field and wx conditions, and actual t/o weight you should expect a V1 of "XXX", a configuration of "XX" and a V.V. above 100 kts of "XX", you might be happy to see "100 kt + your comfortable "XX" amount" on the V.V. on the takeoff roll and be totally wrong in your assessment.
My point is that using strictly V.V. without some specific manufacturers numbers to match up your "seat of the pants" assessment of it's use is to my mind incorrect and should not be relied upon to assess performance takeoff criteria.
The real question is why have the manufacturers not published the performance data using the velocity vector as it is something that is easy to document (at the manufacturers level) and the display of the data ( the Velocity Vector) is already a part of the modern airline cockpit?
Why have Airbus and Boeing not provided airline crews with this easily produced and readily available data?
To my mind that is the key issue in this incident and one that Emirates, all other airlines and the regulatory authorities in every country must contemplate in assessing fault for this incident.
Dune
The velocity vector is a useful "secondary tool" but until the specific performance specifications using the V.V. are documented and mandated by the manufacturer as a check item on takeoff roll, to my mind its' use is "vague" at best. In fact, to my mind it is only slightly better than the "seat of the pants" judgment many experienced Captains currently use to judge the rate of acceleration on a given takeoff roll on a given day.
The V. V. is based the aircraft's computed future speed based upon a current rate of change of acceleration over a given time frame projected forward ("XX speed" will be achieved in "XX time" projected forward based upon current the current rate of acceleration).
This vector is totally dependent upon the performance data criteria selected by the crew in the flight management computers given the actual a/c weight and current runway length, field elevation and airfield wx (temp, wind and QNH).
Case in point:
If I were to take off at MTOW in any given aircraft (A-319 through to A-380 or Boeing equivalent up to 747-400) on a 20,000' runway at sea level at ISA wx conditions, you would expect a max flex t/o (irrespective of weight given the runway length) and a minimal "benign/subdued/non-aggressive/etc?" velocity vector displayed on the PFD during the take off roll through 100 kts given the conditions.
Take that same a/c and put it on an 8000' runway at 6000' above sea level and the velocity vector for the same given weight on that runway would be considerable different. How much V.V. on the PFD is right at that weight on that runway length at that temp at that elevation on that day? How much is "not enough"?
Under a different scenario, what if you take the same a/c on the same day at a "simple airport" (long runway, near sea level, normal temps, etc) and make a gross input error (due to crew fatigue/distraction/etc) in the computer inputed ZFW or max TOW data to calculate the performance figures?
Unless experience tells you to expect that based upon the given aircraft type, field and wx conditions, and actual t/o weight you should expect a V1 of "XXX", a configuration of "XX" and a V.V. above 100 kts of "XX", you might be happy to see "100 kt + your comfortable "XX" amount" on the V.V. on the takeoff roll and be totally wrong in your assessment.
My point is that using strictly V.V. without some specific manufacturers numbers to match up your "seat of the pants" assessment of it's use is to my mind incorrect and should not be relied upon to assess performance takeoff criteria.
The real question is why have the manufacturers not published the performance data using the velocity vector as it is something that is easy to document (at the manufacturers level) and the display of the data ( the Velocity Vector) is already a part of the modern airline cockpit?
Why have Airbus and Boeing not provided airline crews with this easily produced and readily available data?
To my mind that is the key issue in this incident and one that Emirates, all other airlines and the regulatory authorities in every country must contemplate in assessing fault for this incident.
Dune
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time CX
C130 operations - a long time ago in my career - on short field ops we calculated exactly that event - time to 80 kts( for example)
the nav called 'time' with the precalc'd seconds and you either had the speed 'go ' or you didnt - and 'stopped'..
it picked up runway condition / slush mud etc - not entirely relevant to civil ops but the point is there.
I notice we get bogged down starting the friggin clock when we roll the jet ( apparently so we can monitor take of thrust - or time to next coffee break or something??)
Unfortunately it seems that no matter how fool proof the engineers try and design something their model of the real world is continually tested.
I think the highlight of Dairy's post was the observation of how 'non standard' our attitudes and beliefs are with regard to how standardised we really think we are...but arent..?? sorry poor english again.
Several of these posts comment on the lack of incorporation of 4 crew into a 2 crew system - ad hoc etc.
This surely needs to be addressed? more eyes, more seen, does not make.
some really good posts guys ... keep thinking there are some excellent ideas out there..
the nav called 'time' with the precalc'd seconds and you either had the speed 'go ' or you didnt - and 'stopped'..
it picked up runway condition / slush mud etc - not entirely relevant to civil ops but the point is there.
I notice we get bogged down starting the friggin clock when we roll the jet ( apparently so we can monitor take of thrust - or time to next coffee break or something??)
Unfortunately it seems that no matter how fool proof the engineers try and design something their model of the real world is continually tested.
I think the highlight of Dairy's post was the observation of how 'non standard' our attitudes and beliefs are with regard to how standardised we really think we are...but arent..?? sorry poor english again.
Several of these posts comment on the lack of incorporation of 4 crew into a 2 crew system - ad hoc etc.
This surely needs to be addressed? more eyes, more seen, does not make.
some really good posts guys ... keep thinking there are some excellent ideas out there..
That's The Point
Not sure I've read anything like that in the training manual... 
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Agree.
Might even have saved the Manchester United team at Munich
Has been promulgated countless times, after overshoots and 'just made its'
Remember particularly in the 70's when it was being considered
Military use time to distance a fair bit or speed at runway marker
Rules of thumb are enough, we're not talking 3 decimal places !
Might even have saved the Manchester United team at Munich
Has been promulgated countless times, after overshoots and 'just made its'
Remember particularly in the 70's when it was being considered
Military use time to distance a fair bit or speed at runway marker
Rules of thumb are enough, we're not talking 3 decimal places !
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A320-200 Tunisair - near tail-strike
Not the same A/C, not the same WX and a different carrier and location ...... but nevertheless interesting and instructive for me to see what happens to this Tunisair A320-200 when the spoilers deploy.
YouTube - Almost tail strike Airbus A320-200 Tunisair
Apologies if this has already been posted or is deemed irrelevant.
YouTube - Almost tail strike Airbus A320-200 Tunisair
Apologies if this has already been posted or is deemed irrelevant.
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Originally Posted by AutoAbort
Interesting article from Flight International about Flightdeck distractions.
Distractions frequently cause flapless take-offs, NASA reveals
Distractions frequently cause flapless take-offs, NASA reveals
An examination of the US confidential aviation safety reporting system (ASRS) shows that, since 2000, 55 take-offs have been carried out unintentionally in the USA without take-off configuration having been set ...
In that perspective, I must say Airbus developed an excellent concept to avoid that kind of event and I would not think any of these 55 cases came from an NG Airbus ... (?)
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Perhaps there is a possibility of an acceleration rate check, based on ambient conditions and groundspeed, driven by GPS/RAAS and triggered when the TO/GA switches are pushed on departure? Something for the boffins...
So it will be subject to the same input error and be pointless.
If the input is correct then the performance will be correct. I suggest we are concentrating on the wrong end of the problem.
We should be thinking of how to ensure the correct figures make their journey from the airport data and loadsheet...to the performance computer...to the FMS.
That is the key. So simple and yet so full of human factor traps...
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Velocity Vector
I was thinking..
What if we just look at this in simple kinematics terms (not sure of the spelling).
We can create a table that we enter with Vr, move across to TORA and find a resultant IAS 10 second trend minimum.
OK I know this is really vague but if you run the numbers it is interesting that you get a vector that can be anything from 10kts to 40 kts.
These are minimum averages and are independant of weight or conditions. A completely different input from that used in the LPC calcs.
So I start a take off with a fugure of say 25 kts in my head as a guide for this runway/Vr combination.
Just a thought.
What if we just look at this in simple kinematics terms (not sure of the spelling).
We can create a table that we enter with Vr, move across to TORA and find a resultant IAS 10 second trend minimum.
OK I know this is really vague but if you run the numbers it is interesting that you get a vector that can be anything from 10kts to 40 kts.
These are minimum averages and are independant of weight or conditions. A completely different input from that used in the LPC calcs.
So I start a take off with a fugure of say 25 kts in my head as a guide for this runway/Vr combination.
Just a thought.