Melbourne Tailstrike final report
Download animation and report here:
Investigation: AO-2009-012 - Tailstrike and runway overrun - Airbus A340-541, A6-ERG, Melbourne Airport, Victoria, 20 March 2009 |
Commentary states that the lack of performance wasn't realized 'until late, if at all'. Max power wasn't applied until it was obvious they would not get airborne...
Also, I wonder if AF 447 would have occurred if the PFD's displayed the stick inputs (upper right display in automation)??? |
Also, I wonder if AF 447 would have occurred if the PFD's displayed the stick inputs (upper right display in automation)??? The flight controls and engine controls should move - period. Many Airbus pilots will give you the old line that "you get used to it". That is not a good enough reason. You can get used to eating feces for dinner every night if you do it for long enough, that doesn't mean it is a good idea. They can design systems to compensate, like the one you suggest about showing the stick position on the PFD, but that is just compensating for poor design. The problem with Airbus is that they are deeply committed to their current setup, it is in all of their aircraft (except the A300/310 series of course). To go back to a control system that moves and provides feedback to the pilots would be a huge loss of face to Airbus and I doubt they would do it. But it is the only way forward to avoid further loss of life. |
Aside from the FMGS inputs they got wrong that day, I think a vigilant captain might have seen the end of runway markers coming up and just applied TOGA before rotation. That might, and I emphasise might, have avoided the tailstrike.
From the animation, TOGA was applied too late. After several attempts at stick back for rotation, actual rotation commenced about 600m from the end of the runway. TOGA was not applied until about 160m from the end of the runway, well into the course of rotation, and immediately after the instant of the initial tailstrike contact. |
but they got the whole control feedback issue deadly wrong, and it has caused many accidents - who knows how many incidents. |
Quote: Also, I wonder if AF 447 would have occurred if the PFD's displayed the stick inputs (upper right display in automation)??? It would, but it would be a huge political loss to Airbus. Airbus has many good ideas and innovations, but they got the whole control feedback issue deadly wrong, and it has caused many accidents - who knows how many incidents. The flight controls and engine controls should move - period. Many Airbus pilots will give you the old line that "you get used to it". That is not a good enough reason. You can get used to eating feces for dinner every night if you do it for long enough, that doesn't mean it is a good idea. They can design systems to compensate, like the one you suggest about showing the stick position on the PFD, but that is just compensating for poor design. The problem with Airbus is that they are deeply committed to their current setup, it is in all of their aircraft (except the A300/310 series of course). To go back to a control system that moves and provides feedback to the pilots would be a huge loss of face to Airbus and I doubt they would do it. But it is the only way forward to avoid further loss of life. |
I suspect I'll get flamed for this but I still cannot understand how a crew could accept 74 Flex, a 40% reduction in thrust when confronted with a 13hr ULR flight at close to MTOW.
I am sorry I don't buy the HF speak variability of performance figures argument. Not too convinced about crossed out numbers in documentation either. I can happily subscribe to the 'there by the grace of god go I' argument but not in this case. It seems to me GIGO and no thought from the crew about what any of the numbers actually meant. What do you guys think? |
Sqwak7700
What a complete rubbish! |
Care to back that up with some numbers? Look, don't mistake me for a Boeing nut just bashing Airbus. There are plenty of things Boeing gets wrong and there are many design features that Airbus has spot on - but this isn't one of them. It is a poorly designed system by engineers saving a buck without thought to the human interface. Like I said before, you can train people to get used to it, but that doesn't make it good. |
Schnowzer:
I understand why you don't understand. If it was easy to understand it would be an easy fix. Just sack the pilots that do things that is so obvious to you and the problem will go away. Just like EK did in this case. You might wake up one day and find that you missed something extremely obvious to others and you might have a diff. view on HF. Cheers |
Aside from the FMGS inputs they got wrong that day, I think a vigilant captain might have seen the end of runway markers coming up and just applied TOGA before rotation. That might, and I emphasise might, have avoided the tailstrike. You might try reading the report before making (uninformed) comments on it. |
The TAM 320 wasn't caused by anything other than bizarre thrust lever handling, I don't see how you can pin that accident on airbus design philosophy. Thrust lever movement and "conventional" control yoke feedback didn't save the THY crew at AMS. We could compare Boeing and Airbus crashes all day and call it a dead heat, as has been mentioned Human Factors have more of an impact on the incidents you mention than aircraft/flight control design philosophy. That was certainly the case with the report above.
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Schnowser, I agree. Some guys just don't look at what they are doing but are slaves to the 'putr.
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Slight thread drift but..
Thrust lever movement and "conventional" control yoke feedback didn't save the THY crew at AMS. With respect to the report, I read the same thing as Wiz, TOGA was applied before the DER, but this statement in the report explains an awful lot to me.. All four flight crew reported that their perception of the aircraft's take-off acceleration was typical of a heavy A340, particularly a heavy A340-313K. The operating flight crew reported that they did not realise there was a problem with the aircraft's acceleration until they had nearly reached the end of the runway, and the red runway end lights became more prominent. Both operating flight crew reported that during operations from some runways at other airports, it was common to see the red runway end lights as the aircraft lifted off. |
Wizofoz
I think maybe you should try reading the report. It quite clearly states that TOGA was applied 1.5 seconds after the first tailstrike. |
More than meets the eye.
Schnowzer and Scribble,
Given the right circumstances we might all be capable of catching garbage numbers. That is, no other ongoing tasks and with no disturbances. I have it, on good authority, that the period leading up to departure in MEL was very busy and presented several disturbances. Now, I have been in the business for years now and I have seen my share of well managed departure processes. And I have also seen my share of poorly managed departure processes. The point is that it can happen to any one of us, given the right(wrong) circumstances. Just praise yourself lucky that its not your departure thats being investigated. The challenge, of course, is to come up with the perfect and foolproof way of the operating airplanes. Personally I find that an unachieveable goal as humans are not perfect and we are the ones designing and building airplanes. |
Here is a few points from the report:
"The crew’s lack of awareness of the low acceleration until towards the end of the take-off roll meant that, by the time the captain selected Take-off/Go-around (TO/GA) thrust, a runway overrun was inevitable. The increased thrust from that selection increased the aircraft’s acceleration and resulted in the aircraft becoming airborne and climbing away from the ground much earlier than it would have otherwise. The captain’s selection of TO/GA therefore reduced the likely significant adverse consequences of the runway overrun. Well they saved the folks on board "Without a specific method for comparing the actual acceleration to that required, flight crew must rely on comparing the ‘feel’ of the takeoff with their previous experiences. Because the reduced thrust takeoff optimises the takeoff for the local runway conditions and the aircraft’s weight, the acceleration for the aircraft can vary with each takeoff. Due to the variations in runway conditions and weights experienced by flight crews in civil transport operations, that variation can be quite large, and not necessarily directly related to the aircraft’s weight. Therefore, flight crews cannot reliably detect degraded performance until there is something more obvious, such as approaching the end of the runway without lifting off." "A crew’s assessment of aircraft performance during the take-off roll is based on monitoring the airspeed to determine when V1 has been attained. Flight crew are not trained to monitor the distance travelled or time taken to attain that airspeed, nor is this information displayed in any way in the cockpit. The crew are therefore unable to objectively quantify the aircraft’s acceleration between setting take-off thrust and the aircraft attaining V1." "There was significant variation in the take-off performance parameters during the 2-month period examined, and the erroneous parameters used during the accident flight lay within the range of values observed during that period. Furthermore, the following points were noted: •There was no direct correlation between an aircraft’s weight and the FLEX temperature. •Although the take-off reference speeds generally increased with increasing weight, the variation was not linear and the correlation was very weak. •The take-off reference speeds experienced by the crew varied by more than 50 kts. • All four flight crew had experienced take-off parameters in the A340-541 that were very similar to the erroneous values used on the accident flight." "Without a quantitative method for assessing the actual acceleration attained during the take-off roll, or having a ‘reference’ acceleration to compare with the actual acceleration, the flight crew could only judge the aircraft’s acceleration in comparison with their previous experience. All four flight crew reported that they ‘felt’ that the aircraft’s acceleration was consistent with a ‘heavy’ A340, specifically an A340-313K and were not alerted to the low acceleration." "All four flight crew members had encountered a large variation in take-off performance due to: the use of reduced thrust takeoffs; operating a variety of aircraft with significant differences in take-off weight (due to differing routes and passenger/cargo loads); and differences in runway lengths and ambient conditions. The result was that there was no experience-based acceleration ‘datum’ against which the crew could measure the takeoff. That was consistent with the recorded data, which showed that there was no direct correlation between acceleration and take-off weight. For example, the take-off weight for the previous flight from Auckland to Melbourne was 8% greater than the flight from Melbourne to Auckland, but the acceleration was about 80% lower." "In the previous 2 months of operations, the flight crew were exposed to take-off weights that varied from about 150 to 370 tonnes. This large variation probably affected the conspicuity of the erroneous first ‘2’ in the take-off weight that was displayed in the EFB as it, in itself, was not abnormal. Both the captain and the first officer had operated the A340-541 with take-off weights in the 200 to 300 tonne range, and observing a take-off weight of 262.9 tonnes would not have been sufficiently conspicuous to alert the crew to the possibility of the data entry error. The crew’s experiences of differing take-off weights would have been further complicated by their mixed fleet flying. Exposure to large take-off weight ranges makes it difficult for flight crew to form an expected ‘normal’ weight, and has been observed as a factor in other erroneous take-off performance incidents and accidents." |
"Without a specific method for comparing the actual acceleration to that required, flight crew must rely on comparing the ‘feel’ of the takeoff with their previous experiences. Because the reduced thrust takeoff optimises the takeoff for the local runway conditions and the aircraft’s weight, the acceleration for the aircraft can vary with each takeoff. Due to the variations in runway conditions and weights experienced by flight crews in civil transport operations, that variation can be quite large, and not necessarily directly related to the aircraft’s weight. Therefore, flight crews cannot reliably detect degraded performance until there is something more obvious, such as approaching the end of the runway without lifting off." |
That was my (badly put across) point. How an experienced on type crew could sit through that painful acceleration and not realise something as amiss is, from the comfort of my armchair, something I cannot comprehend.
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http://www.atsb.gov.au/media/1358013...012_prelim.pdf
There were 3 crew members in the cockpit still overlooking that the weight and balance input was wrongly not for 500 series but for a 300 series and hence reduce the take-off weight performance. The aircraft scrapped the tail skid so bad that it warranted a write off as the frame 80 etc was so badly damaged beyond economical repair. To maintain a clean image of Emirate no fatal record, the aircraft was extensively and costly repaired to a airworthy condition. |
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