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)???

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.

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.

Care to back that up with some numbers?

Fully Agree !!

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!

As previously mentioned AF A330, Tam A320 in Sao Paolo. And as I said, those are the ones that ended tragically. Who knows how many incidents have occurred that resulted in embarrassment or dirty shorts, but no loss of life (like this Emirates accident).

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

They had applied TOGA significantly BEFORE rotation.

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.

Schnowser, I agree. Some guys just don't look at what they are doing but are slaves to the 'putr.

Slight thread drift but..
Is a nefarious comparison, automation complacency and poor airmanship killed people on the THY 737 at AMS. A simple understanding of N1 settings for basic configs would have solved this..along with a hand on the thrust levers.

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..

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."

While hesitant to cast a stone from within my glasshouse my immediate reaction watching the animation was that if that passed for 'normal' acceleration then that variant of Airbus A340 is more underpowered than I have heard it to be. The acceleration was pitiful.

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.

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.

Is that conjecture, rumour or fact?

I think you'll find there were four crewmembers in the cockpit.

To all those who persist in "blaming" the individuals, with an air of "anyone with that experience would surely notice..." or "not do that" :ugh:

A relatively quick read of the report will reveal that this type of accident (and similar incidents) is far from rare, and affects numerous experienced pilots.

Yes - it is surprising that such things are not noticed, but the facts are clear - they are missed, and without analysing and putting in place steps to try and prevent them, they will continue to do so.

Only comment would be it was back in service ~8 months after the event - given the time to analyse / investigate aircraft, plan what to do, ferry to Toulouse, repair and back in service, it does not seem a massive task?

Appologise, my understanding over the sequence of events was faulty.

The reason TOGA was not selected before the first rotation was that at that point the crew did not realize there was a problem.

THIS however:-

Has more errors per word than just about any post in History.

There were four crew, not three, the erroneous figures had nothing to do with 300 vs 500, and how the hell does writing off the aircraft effect the number of fatalities (which was zero)?

Could you please supply the cost/benefit analysis you must have access to to make this claim?

2 cents
 

7700, Can you explain if Airbus has it so wrong, how the crew of the 757 out of the Dominican had the same result with one pitot tube inop?

There are good indications on the fd when more than one pilot is trying to operate the controls at a time, I don't think this issue was even a slight factor to this accident, been in the bus 13 years. :ok:

TAM was not related to flight control feedback.

Instead of crying out loud against Airbus' automation philosophy I rather would demand an accelleration alarm, giving clues to an aircrew when an aircraft is not getting speed fast enough. This is missing in Airbus and Boeings alike, only seeing it rarely on top-end business jets - where there is never lack of accelleration anyway.

It would be dead simply to imply such an acceleration alarm, be it based on FMGES performance data base or with the RIPS or ROPS or other systems.

Please not another lady shouting at me at the most inappropriate moment!

There are way too many systems shanihaniganging between me, the aircraft and basic airmanship anyway.

It is somewhat inherent to the Airbus fraction that after each incident, especially those involving an Airbus, they are demanding even more automation and protections to help the already implemented automation, just a much as the involved pilots.

To me, Jazz hands has got it dead right:

This statement could be enlarged to the whole Airbus design.

Sure enough it is not the principal factor leading to the MEL incident. However the MFF concept with models with such a variety in performance, number of engines, fuel tanks, system and checklist variations simply increases the risk of a stuff up. The statements of the pilots concerning the acceleration feel is quite symptomatic.

The MFF concept is very integrated in the Airbus philosophy, therefore my criticism.

If you do not know anything, please do not post!
If you have flown an A340/500, do post.

This thread is probably started by some one having a grudge against Emirates to re-open the deep wound just about to be forgotten.

It is more than 2 year old history and any legal documents would be buried deep into the sand dunes.(2 years max safe keeping).

The rumor came from the epic-centre of the volcano in Dubai.

2 operational crews, 1 observer in cockpit.

Strangely, airmech had a better infor/rumor than the pprune here with rumors more than facts. That was 2 years ago.

Needed a longer runway? - Aircraft Engineers Bulletin Board

May be the engineer (airmech) is more down to earth (ground engineer) than the crews dreaming (flying) in the sky.

No,

Two operating crew, two augmenting crew in the cockpit. Would you like their names?

One of the problems associated with putting such an alerting system in place is that they would still require a human input into the system so that the nominal acceleration rate could be computed. It would still be possible to mis-program the FMGC to the point where the alert wouldn't be effective.

The best SOP I've seen to prevent such gross errors is an independent check by two or more crew members, where both do the calculation independently. In addition to comparing their computed results, the crew also must compare the calculated TOW with the one on the operational flight plan. Discrepancies must be investigated and resolved prior to takeoff.

Captain flew 98.9 hrs in last 30 days.....wow

Which is also true of the "MFF" on various Boeings. Presently flying 6 variants of 777 with different weights/speed limits/engines and vastly different takeoff and landing speeds to boot.

Then there's the 757/767 rating and 737 variants.

Before I get flamed, I'll acknowledge the general systems commonality, but I don't believe that's an issue in this or similar incidents.

When you're tired, the obvious suddenly isn't so obvious after all.

You can drop the 'wow' - as we speak, just about every Emirates captain, and every FO as well, is clocking ~98 hours per month - and that's after "factoring".

Being SLF, I may be asking a stupid question, but what about a system that measures the position of the landing gear oleos and sounds an alarm if there's a significant discrepancy from the weight entered by the crew?

Try that in a mostly shorthaul environment - thats Nigeria!

Chu Chu,
In this event the erroneous weight was entered in the Electronic Flight Bag not in the Flight Management and Guidance System.

Acceleration?
 

It appears here that the problem is using a derived figure to calculate thrust based on aircraft mass and runway length.

Surely it's easier to enter known figures - runway length and local windspeed and direction - and let the thrust control system manage the accelleration to achieve a takeoff in the available runway?

This will handle all sorts of situations, such as mistaken TOW as well as factors such as rainfall.

but since when you are 100% sure that nobody will ever make a mistake in correct Rwy length ?
Besides the wind will certainly not wait for you to do a TakeOff in order to change itself..:ugh: