EK407 Tailstrike @ ML
Join Date: Jan 2003
Location: Manchester
Age: 45
Posts: 615
Likes: 0
Received 0 Likes
on
0 Posts
Of course there are human factors involved in this error. I would put it to you that this part of the accident chain is purely human factors related, as opposed to a technical issue.
Surely one of the issues with this is that by bugging the speedtape through the FMS unless you are on the ball it is quite easy to enter an erroneous figure, ie one which the laptop says is correct but logic says isn't. Thus on takeoff the Rotate call will be made parrot-fashion without the usual, expected climb out.
Would things be any different if they were on old-fashioned steam-driven instruments, ie clockwork ASI with manually set bugs ? Maybe the picture would then have looked completely wrong, wrong enough to have been "trapped" before departure.
Join Date: Feb 2006
Location: Germany, South-East Bavaria (Oberbayern)
Age: 51
Posts: 27
Likes: 0
Received 0 Likes
on
0 Posts
I was suggesting that there were two points that the error could have been "trapped", on entering the ZFW figures into the Laptop and on entering the V speeds into the FMC.
Cheers,
DL
As an impartial SLF observer can I just say how unhappy I am with Emirates [can I use that word?] handling of this whole issue. As an outside observer it seems to me that the airline is taking an ostrich like approach to the whole issue rather than facing it head on [sorry for the cliche]. Surely in such a large company 'collective responsibilty' sholud be the management mantra rather than trying to find convenient scape-goats.
The issue of allocating blame seems incidental compared to the number of lives that could have been lost had not the flight crew been aware of the nature of the danger they were in, and taking the appropriate remedial eaction. Emirates seem reluctant [under-statement!]to give appropriate thanks to the flight crew- the 'sweep under carpet approach' seems more appropriate.
Given the choice on the routes operated by Emirates, I think I might prefer to choose other airlines, until Emirates become a little more open and honest in their dealings with the people who really matter.
The issue of allocating blame seems incidental compared to the number of lives that could have been lost had not the flight crew been aware of the nature of the danger they were in, and taking the appropriate remedial eaction. Emirates seem reluctant [under-statement!]to give appropriate thanks to the flight crew- the 'sweep under carpet approach' seems more appropriate.
Given the choice on the routes operated by Emirates, I think I might prefer to choose other airlines, until Emirates become a little more open and honest in their dealings with the people who really matter.
The thrust is calculated so that at any speed below V1, the a/c can be stopped on the remaining runway. Often that distance is less than that required to continue a takeoff after losing an engine.
In order to provide the basis for takeoff performance charts and, these days, software, engineers determine by experimentation and interpolation braking distance from various speeds, weights and runway conditions and then add the mandated margins.
The fancy new takeoff performance software in the laptop uses the braking distance in its calculations.
Now if the laptop software also told the pilots that braking distance and if remaining distance signs were available for distances beyond 3000' where the first runway marks appear (for those cases where more than 3000' is required to stop from V1), the crew would know when the required braking distance came up before V1 that either the weight is wrong or that they did not obtain sufficient thrust at a point where they can get the a/c stopped before going off the end.
In order to provide the basis for takeoff performance charts and, these days, software, engineers determine by experimentation and interpolation braking distance from various speeds, weights and runway conditions and then add the mandated margins.
The fancy new takeoff performance software in the laptop uses the braking distance in its calculations.
Now if the laptop software also told the pilots that braking distance and if remaining distance signs were available for distances beyond 3000' where the first runway marks appear (for those cases where more than 3000' is required to stop from V1), the crew would know when the required braking distance came up before V1 that either the weight is wrong or that they did not obtain sufficient thrust at a point where they can get the a/c stopped before going off the end.
Join Date: May 2007
Location: Western Pacific
Posts: 721
Likes: 0
Received 0 Likes
on
0 Posts
The fancy new takeoff performance software in the laptop uses the braking distance in its calculations.
Now if the laptop software also told the pilots that braking distance and if remaining distance signs were available for distances beyond 3000' where the first runway marks appear (for those cases where more than 3000' is required to stop from V1), the crew would know when the required braking distance came up before V1 that either the weight is wrong or that they did not obtain sufficient thrust at a point where they can get the a/c stopped before going off the end.
Now if the laptop software also told the pilots that braking distance and if remaining distance signs were available for distances beyond 3000' where the first runway marks appear (for those cases where more than 3000' is required to stop from V1), the crew would know when the required braking distance came up before V1 that either the weight is wrong or that they did not obtain sufficient thrust at a point where they can get the a/c stopped before going off the end.
So this would not trap a pilot input error, as happened in Melbourne.
Join Date: Aug 2007
Location: Between East and West Poles.
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
Reduced Thrust Take Off.
I had an fellow Licensed Engineer who became a Flight Engineer. He told me one day, that on a Boeing 747SP going from Sydney to Wellington they used a reduced thrust take off. After gear retraction the Captain called for climb thrust, so he advanced the thrust levers. !!!
Join Date: Feb 2008
Location: Wingham NSW Australia
Age: 83
Posts: 1,343
Likes: 0
Received 0 Likes
on
0 Posts
Increase thrust.
Runaround Valve. Nothing at all unusual in increasing thrust from a Reduced Thrust Take-off EPR to initial Climb Thrust. Not an everyday event, but nonetheless not a rare event by any means.
Join Date: Jul 2000
Location: Dubai - sand land.
Age: 55
Posts: 2,832
Received 0 Likes
on
0 Posts
DonLeslie - the 345s don't just do heavy ULR sectors but very often we operate them on short sectors such as the 3 hour trans Tasman hops, Europe, Middle East stuff.. Anyway - if you follow the SOPS that we had at the time then the error would have been picked up!!
Saskatoon - ECAM screens old bean, not Eicas
Saskatoon - ECAM screens old bean, not Eicas
Join Date: Dec 2008
Location: PDX
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Weight of fuel
@DonLeslie: (Not a pilot. No need to respond)
a) Could crosscheck calculations reveal: You have enough fuel for roughly forty hours in the air (or some other ridiculous figure)? (I'm presuming they had enough fuel onboard to keep that extra 100 tonnes airborne for the planned duration.)
b) A large US manufacturer will apply minimal paint upon request. The manufacturer's weight is monitored that closely. Couldn't the weight and balance calculations produce a figure somewhat in line with that original measure for the specific air frame?
To belabour: The weight and balance sheet for a short flight with ping pong balls would look vastly different than that for an automobile axle shipment halfway around the world. But, in both cases, a similar tare weight should emerge.
Edit: typos
a) Could crosscheck calculations reveal: You have enough fuel for roughly forty hours in the air (or some other ridiculous figure)? (I'm presuming they had enough fuel onboard to keep that extra 100 tonnes airborne for the planned duration.)
b) A large US manufacturer will apply minimal paint upon request. The manufacturer's weight is monitored that closely. Couldn't the weight and balance calculations produce a figure somewhat in line with that original measure for the specific air frame?
To belabour: The weight and balance sheet for a short flight with ping pong balls would look vastly different than that for an automobile axle shipment halfway around the world. But, in both cases, a similar tare weight should emerge.
Edit: typos
Join Date: Feb 2006
Location: Germany, South-East Bavaria (Oberbayern)
Age: 51
Posts: 27
Likes: 0
Received 0 Likes
on
0 Posts
@ White Knight:
That's what I thought. I would have been surprised if your procedures differed greatly from ours but I didn't want to accuse anybody of not following SOPs without knowing exactly what these SOPs are.
Cheers,
DL
Anyway - if you follow the SOPS that we had at the time then the error would have been picked up!!
Cheers,
DL
Join Date: May 2005
Location: dubai
Posts: 375
Likes: 0
Received 0 Likes
on
0 Posts
To address a few questions put forth.
1-TOGA thrust WAS applied after the 2nd Rotate call after no rotation was apparent at the incorrect Vr speed. Therefore they made the correct response but unfortunately by this time the tail was scaping the runway.
2-Flex takeoff thrust does not supply less power than climb thrust (part of the computer program), unlike on some older aircraft types. Therefore, retarding the thrust levers to climb thrust at acceleration height, will not result in more thrust from the engines. I am basing that on past performance training, since these particulars were not taught at EK. Performance training on the Airbus, is less than ideal at EK and I don't think anyone would disagree with that fact.
3-One fellow was discussing how there can be some instances when it is still possible to get airborne on the remaining runway with a failed engine BEFORE V1. Sometimes this might be the case, but there are too many factors to even consider this option. VMCG is one of those factors. Engine failure before V1= rejected takeoff.
On the other hands, sometimes there is obviously enough runway available to STOP an aircraft AFTER V1 with an engine failure, but it is not an option. In fact, the experts have determined that a pilot should be GO MINDED after 100kts and up until V1, which of course means AFTER V1 a pilot should never consider trying to stop on the remaining runway, unless it is obvious the aircraft will not get airborne (something catastrophic in other words)
The manufacturers takes the view that it is better to get airborne after a problem occurs at high speed on the runway (below V1) except in a few instances. Airbus gives 5 examples when a pilot should consider rejecting a takeoff above 100kts and below V1.
Since these guys rotated at what they thought was the correct speed, and given the inherent time delay, they had but one option and that was to apply TOGA thrust and continue the takeoff. Perhaps it was possible to stop in the remaining distance, who knows, but it was not an option.
So they made one mistake, entering a number into either the laptop, MCDU or both computers. The question remains why?
4-Another fellow mentioned that being qualified on 3 types of airbus, each with vastly different performance, weights, (number of engines too) might be a factor. I agree. It was a causal factor and one that should be addressed. It is not uncommon to lose currency on either the A340/A332, which means more than 90 days without a takeoff and landing in one of the types. (A343 and A345 are considered one and the same, in spite of the fact they have much different characteristics on takeoff and landing)
The aviation gods at EK will say there is no issue flying the different types but isn't it interesting that both major and near catastrophic accidents at EK in the past 5 years occured as a direct/indirect result of CCQ on the Airbus. The Johannesburg accident was a direct result of cross-training and the MEL accident was likely in part caused by this policy as well. The Joburg guys had never even flown an A343 prior to their takeoff from a high elevation airport, in an underpowered (relatively speaking) aircraft, and with improper training. This fact, rather explicity demonstrates EK's attitude wrt to cross-training.
In any event, it is more likely for pilots to remain oblivious to an input error in the computers, if they are not as familiar on type. I hope this factor is addressed by the authorities.
1-TOGA thrust WAS applied after the 2nd Rotate call after no rotation was apparent at the incorrect Vr speed. Therefore they made the correct response but unfortunately by this time the tail was scaping the runway.
2-Flex takeoff thrust does not supply less power than climb thrust (part of the computer program), unlike on some older aircraft types. Therefore, retarding the thrust levers to climb thrust at acceleration height, will not result in more thrust from the engines. I am basing that on past performance training, since these particulars were not taught at EK. Performance training on the Airbus, is less than ideal at EK and I don't think anyone would disagree with that fact.
3-One fellow was discussing how there can be some instances when it is still possible to get airborne on the remaining runway with a failed engine BEFORE V1. Sometimes this might be the case, but there are too many factors to even consider this option. VMCG is one of those factors. Engine failure before V1= rejected takeoff.
On the other hands, sometimes there is obviously enough runway available to STOP an aircraft AFTER V1 with an engine failure, but it is not an option. In fact, the experts have determined that a pilot should be GO MINDED after 100kts and up until V1, which of course means AFTER V1 a pilot should never consider trying to stop on the remaining runway, unless it is obvious the aircraft will not get airborne (something catastrophic in other words)
The manufacturers takes the view that it is better to get airborne after a problem occurs at high speed on the runway (below V1) except in a few instances. Airbus gives 5 examples when a pilot should consider rejecting a takeoff above 100kts and below V1.
Since these guys rotated at what they thought was the correct speed, and given the inherent time delay, they had but one option and that was to apply TOGA thrust and continue the takeoff. Perhaps it was possible to stop in the remaining distance, who knows, but it was not an option.
So they made one mistake, entering a number into either the laptop, MCDU or both computers. The question remains why?
4-Another fellow mentioned that being qualified on 3 types of airbus, each with vastly different performance, weights, (number of engines too) might be a factor. I agree. It was a causal factor and one that should be addressed. It is not uncommon to lose currency on either the A340/A332, which means more than 90 days without a takeoff and landing in one of the types. (A343 and A345 are considered one and the same, in spite of the fact they have much different characteristics on takeoff and landing)
The aviation gods at EK will say there is no issue flying the different types but isn't it interesting that both major and near catastrophic accidents at EK in the past 5 years occured as a direct/indirect result of CCQ on the Airbus. The Johannesburg accident was a direct result of cross-training and the MEL accident was likely in part caused by this policy as well. The Joburg guys had never even flown an A343 prior to their takeoff from a high elevation airport, in an underpowered (relatively speaking) aircraft, and with improper training. This fact, rather explicity demonstrates EK's attitude wrt to cross-training.
In any event, it is more likely for pilots to remain oblivious to an input error in the computers, if they are not as familiar on type. I hope this factor is addressed by the authorities.
Join Date: Feb 2008
Location: Wingham NSW Australia
Age: 83
Posts: 1,343
Likes: 0
Received 0 Likes
on
0 Posts
Tare weights - Minimal Paint - 40 hours endurance
fotoguzzi - I think I know what you are driving at. 40 hours fuel - Not on this aircraft. Minimal paint - irrelevant in this instance. Tare weight - I guess you mean Aircraft Empty Weight. Mate, the problem occurred because an error was made in entering the Takeoff weight and from that error the resultant V speeds were incorrect and a lower than required thrust setting for takeoff was used. No rocket science, just an undetected error made which had the potential to cause a much worse outcome. I recommend the post by mensaboy to you, it is well thought out and makes a lot of sense, to me at least.
Join Date: Jun 2002
Location: Dubai
Age: 55
Posts: 313
Likes: 0
Received 0 Likes
on
0 Posts
mensaboy, well said.
If I may add......
The fate of this flight was sealed the moment the laptop was put away.
Many people do not understand 4 engine take-off performance and that is why they reason "could the pilot not feel there was a problem". On day 1 of my A340 conversion, I was told "You are going to see a lot more of the departure end of the runway" and this is a fact. A correctly calculated takeof performance will optimally utilise every inch of runway and is very often TORA limited rather than the 2nd segment climb limits that usually dog the twins. In the MEL case the guys would have run most of the runway and then close to the end would have rotated at the calculated Vr(albeit an incorrect one).......why would the pilot have thought anything was amiss until the airplane did not lift off.
In terms of knowing the numbers....well, I don't think I have done a 350 ton take off in a 340 since my CCQ and I have been here a while(I have seen it done many time from the blind seat in the rear right corner). This is an academic point because do you really want to rely on the pilot operating on the wrong side of the clock to sense an error, or would you rather see more robust SOP's in place.
I also don't believe that these guys just ignored SOP.....I have never flown with a captain that did not do the performance check. The question should rather be did they follow the correct procedure(training) and if so, how did the error slip through. I personally have had to sit down and have a good review of the procedure. I don't know why the FCOM3 brings the qrh into the greeddot check. I think we should simply have a dispatch calculated greendot next to the Estimated TOW(on the LIDO flightplan)and next to this we write the laptop GD and the MCDU GD. If these 3 are close together you cannot have a gross error in TOW.
I might also add that the pre-departure workflow is total chaos. This has been identified as a problem but not addressed. It is like a ping pong ball in a jacuzzi.....all over the place. It is highly probable that the performance check was interrupted by some obscure requirement like security demanding their checklist be signed.......
Anyway, just my tuppence worth.......
If I may add......
The fate of this flight was sealed the moment the laptop was put away.
Many people do not understand 4 engine take-off performance and that is why they reason "could the pilot not feel there was a problem". On day 1 of my A340 conversion, I was told "You are going to see a lot more of the departure end of the runway" and this is a fact. A correctly calculated takeof performance will optimally utilise every inch of runway and is very often TORA limited rather than the 2nd segment climb limits that usually dog the twins. In the MEL case the guys would have run most of the runway and then close to the end would have rotated at the calculated Vr(albeit an incorrect one).......why would the pilot have thought anything was amiss until the airplane did not lift off.
In terms of knowing the numbers....well, I don't think I have done a 350 ton take off in a 340 since my CCQ and I have been here a while(I have seen it done many time from the blind seat in the rear right corner). This is an academic point because do you really want to rely on the pilot operating on the wrong side of the clock to sense an error, or would you rather see more robust SOP's in place.
I also don't believe that these guys just ignored SOP.....I have never flown with a captain that did not do the performance check. The question should rather be did they follow the correct procedure(training) and if so, how did the error slip through. I personally have had to sit down and have a good review of the procedure. I don't know why the FCOM3 brings the qrh into the greeddot check. I think we should simply have a dispatch calculated greendot next to the Estimated TOW(on the LIDO flightplan)and next to this we write the laptop GD and the MCDU GD. If these 3 are close together you cannot have a gross error in TOW.
I might also add that the pre-departure workflow is total chaos. This has been identified as a problem but not addressed. It is like a ping pong ball in a jacuzzi.....all over the place. It is highly probable that the performance check was interrupted by some obscure requirement like security demanding their checklist be signed.......
Anyway, just my tuppence worth.......
Join Date: Aug 2006
Location: EGCC
Posts: 273
Likes: 0
Received 0 Likes
on
0 Posts
Given today's sensor technology, it is surprising that not at least one of the following solutions has been adopted:
- "weighbridge" concept: a/c passes over a strip of load cells on taxiway or at runway threshold, where actual take-off weight is determined and relayed to cockpit crew for verification of their loadsheet calculations
- built-in weighing capability by using load cells in landing gear suspension to continuously monitor actual aircraft weight at any given moment on the ground.
Join Date: Jun 2001
Posts: 1,451
Likes: 0
Received 0 Likes
on
0 Posts
If something similar to Kennytheking's comment (below) isn't part of the final report, I'll be very, very surprised.
I might also add that the pre-departure workflow is total chaos. This has been identified as a problem but not addressed. It is like a ping pong ball in a jacuzzi.....all over the place. It is highly probable that the performance check was interrupted by some obscure requirement like security demanding their checklist be signed.......
Al Fakhem
Self weighing aircraft ? Been discussed before,e.g.
http://www.pprune.org/questions/1523...hemselves.html
As for tarmac weighbridges,who pays for installation,maintenance,calibration ?
http://www.pprune.org/questions/1523...hemselves.html
As for tarmac weighbridges,who pays for installation,maintenance,calibration ?
