Alamah
 

So the smoke in the cabin a direct result of tail strike??

GearDown&Locked

I don't know for sure but I suspect both the speed relationship with time and with distance are non-linear.

I'm a great believer in K.I.S.S. and in this case you don't need complex integrals of ground speed to get distance - if you (or your computer) can calculate the expected time to V1 & VR for the weight and power settings, then you check your speed at those times - if your speed is below the projections you're running into trouble, but at least you know you have the tarmac left to stop. If the speed is at or above projections at those times then you're good to go.

This approach is inherently safer than measuring time to V1 - what happens in that case if acceleration is low? You could easily find yourself in a position where you don't have space to stop.

Certainly CAN be a "paper pusher's heaven" if the company isn't committed to quality and continuous improvement.

In the real world, customers will tell you everytime when you're providing a rubbishy service or product, either with or without ISO 9000 certification.

Dysag

Exactly :D

Revman2 is right, it's a question of corporate commitment to quality, and whether its just pushed down from the top.

Turns out there is a specific application of ISO 9000 type standards for aerospace that "recognizes the role of regulatory authorities":
Society of Automotive Engineers (SAE)
AS9100: Quality Systems
Aerospace - Model for Quality Assurance in Design,
Development, Production, Installation, and Servicing
NIST GSIG: SAE AS9100: Quality Systems/Aerospace

All this is no panacea though, it's still up to the people involved, and more importantly (as reflected in this thread) the corporate culture -- whether ISO certified or not.

I agree with Bernardd 173. Waiting till V1 to get an acceleration check would be too long and the V1 calculation and would be invalidated by the initial error anyway.
A time check to 80 knots would be much more useful, and guarantee that any subsequent rejected take-off would be in the low speed regime and with sufficient runway to stop.

"And so speaks the old guard"

so obviously your customer is consistently wide of the mark as they pay you $$$$$$$$$$ bucks for your consistently poor product that complies with their consistently poor performance markers...idiot!:ugh::ugh::ugh::ugh::ugh:

All this discussion about times to V1 and assessing whether the take off is proceeding normally is all very interesting. BUT, the problem is that it’s very subjective.

Risk management design just doesn’t allow this type of guesswork into such critical phases of flight.

We need to come back to the take off data as designed by the manufacturer and certified by state authorities as the reference performance document .

Data is accessed on every take off, whether it’s via tables or laptop and, (unfortunately) relies on human input to obtain correct figures. If the crew, on the day, make an error in the input data, then they’ve made an error and wear the consequences (aircraft loss, damage, injury etc) as seen in numerous incidents and accidents with varying outcomes.

This error though, is the end result only. In most take off events such as this, there are generally systemic issues that prevented error trapping at multiple points during the pre flight, start, taxy stages of the flight, before the aircraft has even lined up on the runway.

We have to accept that it’s “normal” for all of us to make errors. That’s why we design processes that supposedly mitigate against the types of errors we are talking about.

Design of error management and trapping processes and procedures is the responsibility of management, not the responsibility of line pilots. Crews should follow these SOP’S with the reasonable expectation that they contain appropriate traps to prevent that final error.

If crews choose deliberately ignore SOP’s, then, yes, they have to accept responsibility.

But, if the process itself is flawed, then it’s senior management who must accept most of this responsibility.

Sadly, history has proved that flight crews are often the scapegoats for senior management shortcomings. This event will probably be no different.

Unfortunately this thread is littered with "Stable Door" solutions for dealing with gross errors. (Most are assuming some sort of gross error in the takeoff weight calculation and/or thrust setting).

Threat and Error Management (TEM) should have trapped any errors long before the aircraft started the takeoff run.

Timing and/or distance acceleration checks are just too late as any errors so discovered invalidate both the "Go" and "Stop" calculations (and probably use the erroneous information anyway !)

mrs nomer
you just beat me to the same conclusion as I was composing this offline :8

Has anyone built and tested one of these yet? http://www.patentstorm.us/patents/6133857/description.html Not that I have seen, but then I am not a pilot, simmer or aircraft engineer. I guess that many would say that such a device is an unnecessary expense for what amounts to a double-check. Others might see it as an essential piece of safety equipment.

The key element in this design appears to be the independently derived real-time data, which does not rely 'assumed' values entered before t/o, but calculates them during the roll. As long as the right airport and runway is entered into the FMGC, it should 'work'. For complete confidence, link the system to the auto thrust.

NOT Guesswork
 

We're not talking about "guesswork". We're talking about charts that should be in the documentation for the aircraft that give time to accelerate to some point short of V1 that will tell the pilots whether they are accelerating properly. This should be independent of and a cross check on any other calculations made. I can't believe that the major airframe manufacturers don't have this data from their pre-production flight testing. Low acceleration can be caused by more than gross weight errors. Weak engines or a dragging brake could also be at fault and not have anything to do with input error by the crew.

Although the preliminary report will probably clarify this, it seems clear to most of us here that they weren't accelerating fast enough and should have recognized it. Although management should give them the tools to recognize insufficient acceleration, and maybe did, it seems like the crew was asleep until the end of the runway loomed in the windscreen.

Acceleration check is NOT the solution
 

Gentlemen, again...

I have to agree with mrs nomer and ZimmerFly. This should have been trapped before the aircraft starts rolling. I think the SOP's we use at EK are wellequiped for that, but unfortunately, lapses do happen, especially operating in an environment such as EK for reasons well explained before and in other threads.

GearDown&Locked:
Your check would indeed work if you knew the correct v1/vr/v2. If the error has been one of entering the wrong weight, your speeds will be a lot lower then required, and even with your acceleration check being ok, you will run out of runway before getting airborne. And this time with a safe feeling because your acceleration check has been ok...

Just for your info, on the typical EK A345 operations, we do very short trips on the A345 as well as the ultra long haul it was designed for, Hence, our v2 speeds will range from somewhere in the lower 130's up to the higher 170's.

Again, about the whole acceleration check thing. As I posted before I am completely AGAINST it. It is NO good way of checking your take off numbers. If you do your checklater in the takeoff roll, it is too dangerous to stop. You might have encountered more tailwind then expected, a windshear, ... Since you don't know if you can still stop, it is ALWAYS better to hit the TOGA and GO!!
I know that you could calculate the correct GS vs. Runway remaining etc.. but then you would get kind of conditional speeds. Like in: Before the v1 of xxx knots we call STOP unless the GS is XXX and the runway remaining etc etc... Not a good situation for a speed designed to make a QUICK STOP/GO decision.

Whilst an acceleration check at 80 knots vs. remaining runway might sound like a safer option, since you will always have enough runway to stop if the check should be unsatisfactory: even this check would be useless. At lower speeds such a check can only be done out of a static TO condition, e.g. beginning of the runway, stopped, applying thrust. Loads of time we enter the runway for a rolling take off. If this is done in an expeditious way, we are above 30 knots by the time we apply TO thrust. An acceleration check at lower speeds would thus be invalid and set you up with a false sense of safety.

Conclusion: the ONLY way to stop this kind of errors is to either have the ACTUAL aircraft weight at your disposal for a crosscheck (which the industry wouldn't like) or as mentioned in the start of my post, by trapping the error before the doors are shut.

MR8

The latest from MEL is that the evaluation work on the repair has just finished. Rear pressure bulkhead is cracked . Aircraft has been moved into the Old Ansett hanger at a cost of $28,000 per night ! Rumour that an Insurance write off is now being considered as cost of repair and requirement to get the a/c to Toulouse (unpressurised at 10,000ft ) to carry out the repair work is going to cost a fortune. At least 3 months out of service for repair work to be completed.:{

Isn't it because it was not trapped the very reason why another level of scrutiny is required? It's all very well to say something should have been trapped, but that's no bloomin' help after the event passed through the trap.

And that is the problem.

If you want to build a system to catch errors in another system, then you have to assume that everything in the system being checked could possibly be screwed up.

If there is a possiblity that the weight can be input incorrectly into the first system, then you have to allow that the same error can be made if the weight is input into the second check system.

There again, if the weight could be derived automatically from sensors or weighbridge, why would we need the second check system anyway?

The main idea is to give you some predictive notion of how fast you're going to reach your calculated V1, for instance.

IMHO this aid could be as simple as coloring the speed trend arrow from red to yellow to green while on the TO roll, depending on the acceleration the A/C versus the distance it travels on the ground. This is not a system that checks another system, simply a visual cue for the numbers the pilot has punched in.

If you keep getting a red arrow along the TO roll until, let's say 80 or 100 KIAS, it means that you're not getting enough acceleration to get airborne inside the RWY distance. V1 doesn't come into play here as you could be too slow for TO but well inside a perfectly safe braking distance.

GD&L

...I think you mean lambert, don't you, woodja 51?...

not Dude! :ok:

For info the outfit that I am familiar with uses reduced thrust / flex takeoffs wherever possible and I think that most outfits do. In lay terms this uses an "assumed temperature" method of calculating thrust that "fools the aeroplane" into thinking that it is weight limited due to ambient temp.
Hence the aircraft always rotates at about the same distance from the end regardless of weight. (Sounds funny until you think about it / less weight - less thrust).
Following on from this the length of the trend vector is always roughly about the same - regardless of weight. In the particular aircraft I am familiar with it is about "25 - 30 kts in length". The only time it varies is on a light weight/high thrust takeoff - unusual but possible due to contamination or MEL requirements etc. In this case the thrust vector is longer. So a simple "gross error" check can be made very early in the takeoff roll - like just after thrust is fully set.
In my aircraft, if the length of the trend vector is less than 25 - 30 kts - stop! It can be done so early in the takeoff roll that the stop is quite gentle - i.e not a passenger screaming abort at high speed. As I'm sure most drivers are aware the trend vector is a fabulous indicator of wind shear on the runway and I am a big believer of the PM being "trend vector aware" during the takeoff roll.

Following the Auckland accident I tried setting up the FMC (in the Sim) with the ZFW set as the TOW and believe me the trend vector was really short - like about 5 - 10 kts. Unforunately the heavies in our airline didn't want to consider introducing the idea of trend vector monitoring by the PM as standard. They did concede however that it was acceptable as an "individual airmanship check".

Interested in whether other use this or considered views.

I guess the per-night charges at LBA back in '85 were relatively cheaper, as a TriStar spent some time there after a landing overrun. (watching it get put back on the runway and moved away was a local spectator sport for a couple of days)

Photos: Lockheed L-1011-385-1 TriStar 1 Aircraft Pictures | !!!!!!!!!!!!!!=

Smilin Ed,

I can't agree with you at all.

In a very dynamic situation at speeds in the order of 160 KIAS, it's simply not possible to look outside and accurately determine whether planned acceleration is matched by actual. The aircraft at this stage is travelling at over 250 feet per second.,

Stick to the take off performance data. It's the most empirical data.

Do the commercial departments weigh up the cost of the risk that reduced thrust take-offs represent, versus the money they save? Everyone assumes they do, but do they?
Clearly, if you are going to severely damage (or worse) an airframe every year or two by planning EVERY take-off to involve rotating at the end of the available runway (and you cannot {as proven} have zero error in such ops= an accepted level of risk/loss), there has to be an enormous benefit in engine life/maintenance to offset.
As PIC and accepting the risk, shouldn't you be privvy to those numbers?

GMDS , your sentiments on accountability are so right. Its sickens me how the other " professions " are never held to account for their bad day at the office. Sorry dont mean to create a thread creep. But I have more respect for every single one of my colleagues ( brown nosing incapable office types excluded), but not a single member of those " professions" .

As prop jet says, Airbus makes use of the full length of every runway in their performance and reduce the thrust as much as possible to a minimum allowed value. You're most welcome to use more thrust, or TOGA, which would shorten the take-off length. Most airlines promote the Flex take-off for engine life/cost.

Thrust may not be flexed below 25% (A340-300) 40% (A340-500) ref FCOM 2.02.01 pg 14, of the entire thrust and all climb gradient segments must be made.

This is to say, that on a wide body in general, medium to long flight, you will always be having the opportunity to visit the far end of most runway rather closely when rotating.

Screwing up the figures or weights, will always have a disastrous effect.

Errors
 

Reading the postings, it seems that people think that the risk only lies in reducing thrust - not so!
Even if you would use full thrust on every take-off, if you have determined the associated speeds with the Zero Fuel Mass, instead of with the Take Off Mass, you will probably scrape the tail on rotation. Granted, it will happen not so near the departure end of the runway, but still the airplane will be damaged.

As for self weighing aircraft: they do exist! Many cargo aircraft have such a system. Not terribly accurate, but it should provide protection mainly against gross Centre of Gravity errors. However, if such a system is u/s, aircraft dispatch will be allowed according MEL - and then, safety is provided, as on any other aircraft, by rigorous procedures.

Iso 9000
 

Mig 15, fully agree with you. Never read such a pertinent description of ISO 9000 so far.

Willy Henderickx
Loss Adjuster

Flight Global reports pilots have resigned.

Nobody ever gets fired from ek!

Resign = Admit responsibility for the error and take your saved company scheme cash.

Sacked = Don't admit full responsibility for the error (other factors also at play) and company won't let you take the cash = BLACK MAIL!

So....Your liablilty (they win when you resign as not their fault). Part company liability possibly (they won't pay out your cash and they win when they fire you).

let me rephrase, ek always wins as you resign as never ek's fault?

We aren't talking here about 160 knots. The decision has to be made well before that, probably not more than 100 knots. In any case, it has to be before V1 and in time to abort before V1 and stop safely in the remaining runway. On fields without Distance Remaining boards, or where you can't see them, it has to be determined by time. If you don't want to do it, fine, just keep on they way this crew did. They (and their passengers) are still alive, just out of a job.

Does this mean that V1 and Vr are always the same?

from Air Transport Intelligence - Pilots resign
 

Pilots resign after Emirates A340-500 accident
Kieran Daly, London (01Apr09, 13:11 GMT, 155 words)

The pilots flying the Emirates Airbus A340-500 that suffered a severe tailstrike at Melbourne on 20 March have left the airline.

A spokesman for the carrier says: "I can confirm that they have resigned." He declined to give any further explanation.

The aircraft (A6-ERG) remains in Australia after being extensively damaged on take-off from the 3660m (12,000ft) runway 16 during which it suffered at least one tailstrike and is reported to have struck antennas just beyond the runway end.

It climbed to an intermediate altitude before dumping fuel for about 30min and then returned to Melbourne instead of continuing to Dubai. It landed without further incident.

No further information on the cause of the accident has been released, although ATI understands that suggestions of a problem with one of the four Rolls-Royce Trent 500 engines have been ruled out, despite passenger reports of seeing sparks or flame from one of them during the take-off run.

Source: Air Transport Intelligence news

From early days, we have seen the concept of lets blame the pilot, particularly if they cannot answer for themselves. In some cases the situation just like this one, can be part pilot error, but often there are other facts that come into play, and if it suits the operator they can be smoothed over.

Does appear that in this case the pilots made a severe error of judgement, but then the system of checks should have caught the situation, long before it became life threatening. In this case the operators of the aircraft, are sitting back in their offices confident that they have had justice done. However they are failing to understand that wall papering over the cracks does not fix the problem.

I am sure that on this forum, there are many who are thinking "there but for the grace of God go I". It will interesting to see what change of operating procedures Airbus will bring out to avoid this and other situations coming back to haunt.

As for the pilots, would have thought this incident would have made them better pilots and should not be a reason to put them on scrap heap. Certainly showed considerable skill in their handling of events after the scrape.

As an after thought, I wonder if the rest of the fleets bulkheads have been checked, if the story put around of regular over loading has merit, perhaps some of the damage was already there and was only compounded by the incident.

Regards

Col

QA standards at least in Australia, is focused on procedures and paper flow. It has nothing to do with quality of product at the end. It has nothing to do with even if proper process takes place, what it means is the flow of events is docuemented and is followed.

One could be producing the same crap product day in and day out but you could still meet the needs of the QA policy.

So the paperwork could be perfect, but the actual product like in this case could be flawed.

Regards

Col

Ed,

The issue here may well have had no different result if the wrong speeds were used. ie the acceleration to (your speed) of 100 KIAS would probably have been within a few seconds of normal.

The problem could have been trying to rotate the aircraft at much too slow a Vr. The aircraft just wasn't ready to fly. They would also have been above the "wrong" V1, and we are all trained to go after that speed.

As has been said before, it is an extremely dynamic situation and valuable seconds would have been taken in wondering why the aircraft wasn't responding. The rotation process over say 5 seconds would have consumed well over 1000 ft in itself, and probably much more with the drag of a continuous tail strike.

The hindsight committee will no doubt say they should have lowered the nose to the correct pitch attitude and immediately apply TOGA thrust. The crew on the night was faced with a situation that they had never ever seen before - so comment after the fact is of little consolation to them.

Time assessment on very heavy take offs, once again, would be a subjective process, even at 100 KIAS. I can't see authorities approving such a system unless it was able to be calulated for every take off. That would also require inputs for possible dragging brakes, airframe deterioration etc etc etc.

It's just not possible to do it accurately.

To those who seem to think that the resignation of the pilots makes the results of the investigation fait acompli, this may or may not be true about the internal EK investigation but remember, there will also be an independent investigation by CASA. CASA has a pretty good reputation for independence and I would bet that "if" an error was made, the very next question will be "why". While I don't really expect much introspection from EK, I would by shocked if CASA refrained from looking into the human factors aspect of this.

ATSB & CASA would/should both be interested.

I'm no performance guru, but I think we could do it accurately. Why have the military persisted with timing take-offs if it is such a difficult thing to get right?

Surely there could be a chart for your a/c type and engine configuration, down the Y axis is the N1 %, across the X axis is the weight, where they meet is the maximum time to 100kts.
Question for the performance types; how would the actual ambient temp be taken into account with something like this? Could you have bands of say "0-10degrees" 11-20 degrees, and 21-30 degrees, or would that be far too course?

Here is how I imagine it working; if for example you put the data into the laptop and it came out and said max time to 100kts is 35 seconds. You then trundle out to the runway and roll, at 35secs you notice you are only at 98kts, either abort or TOGA and off you go, if you get to 35secs and you are at 85 kts...abort.

I am looking forward to being corrected and having the weak points of this method pointed out as it will help me learn :)

Physics
 

Not being a rocket scientist but Framers idea is quite plausible.

The other alternative as I said earlier is to use toga and those speeds for max TOW - that way ( almost) no take off becomes marginal ( except where you are below max structural- which in Emirates happens only in rare occasions).

Turning a high performance aircraft into a marginal performing one - which is what the current procedures end up doing.

Ask the punters if they want to pay an extra few dollars to use full power - or not... once again like telling them we fly slow and get them to places late when they have paid for a ticket - just to save fuel.

Granted, if you measure all variables with a micrometer - so that you can extend the field length out to a 'balanced field' ( where you can stop or go at V1 within the avail field) then this might save engine life etc but get any one of these wrong ( pax/pallet weights/bit more tailwind at one end of the runway etc) then all of a sudden you have no buffers left.

From basic newtons law stuff - s=ut+1/2 at.t

ut =zero therefore

at any point s=1/2 a. t squared.

a= comes from the accelerometers, therefore if constantly integrated over the changing values of acceleration a figure for time to get to a particular distance is really easy. ( yeah I know that is the trend vector)

All this information is on the jet....position/accel/et etc

I really think it would be possible to use the graphical method that Framer comes up with to come up with a gross error check point.

HOWEVER.... there is already gross error check points ( green dot/vref for the FMC weight etc) and these were ( possibly) not picked up.

Another possible and easy check would be for the performance figures to be pre calc'd for the ETOW by the company and transmitted on the OFP for the predicted take off conditions. or via acars. (Or.... even up linked like some operators)

This should be done on every takeoff to work out regulated anyway ( but it isn't where I work until the pilots do it for most takeoffs)

Would at least give some ball park numbers... but once again it has to be checked by someone ...

I think this is the point of all these possible solutions.... they still require a process to be followed.

Might reduce the swiss cheese holes but still wont stop the problem - just drive the stats out to past 1x 10-9.!

Anyway I really feel for the guys - these mistakes - if that is indeed what happened could happen to anyone of us.

We dont live in a perfect world the more we model it to suit ourselves the more it jumps back at us!

At CX we uplink the Takeoff data from the main frame in HK. We then enter it whilst carefully crosschecking the load sheet in a SET routine patter.

However, it is still possible to screw up the data entry and have both guys miss it.

We are only human after all.

The ONLY way is for the aircraft to weigh itself and come up with V1 VR and V2 numbers which if more than a few knots out wont let you enter the numbers from the RTOW calculations without giving you a clear warning message first.

Until this happens, no matter which way your company does it, there is no way to take out the "human error" aspect.

Just be slow and methodical, know you aircraft and what to expect.