You clearly have never dealt in Airbus' system of Perf Calcs :{

There is no logic to the Speeds / Flap setting used... Even on 1 type, you cannot get a "feel" for what the figures should be. Try flying 3 or 4 variants, and much as I would like to be able to "gross error check" the figures, all you can do is type whatever the printer/computer spits out. Your control of the situation is checking the data input(s).

Not safe or satisfactory IMHO, but we are just the employees at the end of the chain :oh:

NoD

Obie, I presume you are refering to my input on this thread? Anyone with half a brain and familiar with performance graphs would not be in any doubt about the weights quoted. Yes, some professionals are a bit of an embarrassment.:rolleyes:

Quote:

"I would have thought that any one with half a brain would know 1000kgs is a tonne!"

Agreed, but Hot Dog's missing 'k', or zeros (330kgs, 230kgs) shows how significant a typo can be.

Sort of makes the point of this thread, I suppose...

tuskegee airman made a very pertinent comment pertaining to the essence of this accident.

We are all human, and humans make mistakes.

Aviation is about managing those mistakes so they don't become significant threats to flight safety.

This tailstrike is remarkably similar to the SQ tailstike at AKL. The SQ pilots entered the ZFW in the TOW line of the FMC.As the fuel load was aprox 100 tonnes the end result was the same.First digit in the the TOW line was entered as 2 instead of 3.

I wasn't actually referring to you Hotdog!
However, now that you mention it...
why don't you stick to engineering and leave the flying up to us? :ok:

Dear Obie

Desperate got the drift, you didn't.

Embarrassing, isn't it, as you pointed out.

Quote:

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Desperate

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Desperate; this is a desperate statement considering the fact that HotDog was merely following the previous posts and the fact that the 000's were missing took nothing away from HotDogs argument. Anyone who has been following this thread would have understood exactly the point that was being made.

What next? Do we have to use the full word kilogram insted of kg or nautical miles per hour instead of knots, instead of kts...this could go on forever.:ugh::ugh:

Please don't turn thread into pedantic ramblings and trivia...let those with something constructive to offer make their point without being picky on trivial points.:ok:

+G

It is not about picking on trivial points, far from it.
It is about all those self appointed astronauts who just can't/won't understand how a experienced crew could put in a 2 for a 3 and not detect it. In their contribution they then make similar typos, like nuatical .... or assumptions. To me it was clear that 330kgs meant 330'000kgs, but I would never generously round down even a widebody by 999kgs, so it is basically a error.

Picking-up such typos is just what some discussions are about. I simply hate the kind of contribution like ".. they should really have picked it up. I fly 20 different types of boeingbusses, but I can smell a wrong Vspeed just by my professionalism .." - implementing this could never happen to them and the MEL crew was just a screw-up.

That was my sarcastic drift, now back to serious theories ....

Pool, I agree that these little typo's can lead to big mistakes...In an aircraft...on these threads can't we allow a few?
+G

Earlier I proposed having the laptop software provide required braking distance from V1 and using that as a signpost, but Oakape ably pointed that a bad weight invalidates the braking distance.

An alternative is having the software show time to 80 kt.

Assuming the software integrates thrust, acceleration and speed over time (as opposed to simply looking up static tables), time and distance to V1 are numbers the software must derive for a particular runway, weight, altitude, temperature, gradient, thrust setting, wind component etc. since the required runway length is the sum of distance to V1 plus the greater of braking distance for a V1 reject or distance to screen height without an engine plus required margins. On the way to V1, the software also derives the time and distance to 80 kt.

If you don't have 80 kt. by the expected time, you are either over stated weight, under thrust, have a brake dragging etc.

software
 

The problem is that certification standards won't allow full integration.
The FMS is driven by a 1970's 8086 processor that CAN'T do single point takeoff calculations.
The class 1,2,3 on board that can are not allowed to push weights and V speeds into the FMS.
Alltogether they are not allowed to talk to and synchronize with the weight and balance system on the ground . So it is the pilot's mark1 mod0 eyeball and brain to make sense of the lot and transpose takeoff data from one to the other.

Its all about safety they say.

But if banks (who are even more paranoid about safety) would think the same about a carbon based lifeform and safety in the loop, there wouldn't be any ATMs. Cash would still be delivered by the postman.

The legislator must perform a 180 and allow the push of data into the FMS and if it is just for a plausibility check.

(Okay pool... I am sure you ll find a reason to have a go at me again. Secretly I believe you are my ex-wife)

RatherBeFlying...

Would that not require all airfields to install "distance markers" of some sort .... paint/post/signs ..


Otherwise how do you know when you've reached this "critical acceleration point".


More to the point what do you actually do ..... stop,go, more power and how do you arrive at the decision?

To be truly effective surely it needs to be an "always stop" choice which then creates multiple stop decision points?

herkman, I'm afraid you're beside the point.
From what I understand, every weights in MCDU and System Display were according to the load sheet and a TOW of 363 tonnes.
All weight information presented to the crew by the airplane screens were correct and in total accordance with the W&B.

The only mistake was to type in the Performance laptop a 2 instead of a 3, 263 instead of 363.
Actually, VERY easy to do that kind of mistake.

In my eyes, the best chance to catch that mistake was to question that extreme 74 degrees Celsius as a FLEX when you go for 14 hours with a full load ...

I HOPE ??? I would have caught it ...
By now, learning from their experience, I HOPE I would get it.

Obie your comment was too cryptic for me. Were you talking about my remark re EPR 1.14?

If so, please explain?

In return, my take; was once they had dealt with all the crap before start (tiredness, company procs, distractions etc) and were taxying, that there was only one chance for them (and in future any of us all) to recognise the bullsh1t, and that was to ask the simple question - "doesn't an EPR of 1.14 a look little low tonight, given that we are departing for 15 hours at 10t below MTOW??"

Even if they had recognised this at the point of setting thrust on takeoff and gone TOGA, yes - it may have still been a tailscrape, but that would have been on the runway, and as an incident would have died a natural death many pages ago.

Just a suggestion :O

When the fuel figures are sent back by acars, additional info of Rwy in use/OAT/Surface wind could easily allow some gross error check figures to be added to the loadsheet.

In fact, they could relatively easily add the whole set of figures which would be even better.

However, in the interests of time/money etc, a flex and green dot would suffice.

It shouldn't be difficult to do, they have the software already.

If some rocket surgeon posted this weeks ago, my apologies, too much to read now. :)

Proven concept at all NATO bases since....well forever! :)

MM5.5, I agree with having the FMS do these calculations -- if only we can get the certification authorities to get their heads around it.

In fact, it seems that laptops with manufacturer sanctioned software is an end run about the certification bureaucratic hoops involved with putting these capabilities into FMS.

Introduction of laptops into cockpit performance calculations seems to have increased the proliferation of information sources already populated with FMS, performance charts and ACARs -- and has introduced more ways to get things wrong as we have also seen with MK in Halifax.

If the crew is expected to dash off a quick critical calculation in a compressed timeframe, they need a straightforward SOP that perhaps excludes unneeded bodies / distractions in the cockpit while this is being done.

42psi, both time and distance to 80 kt. (or other speed if necessary) are equally valid for performance monitoring, but I don't think we will see distance boards put up anytime soon and stopwatches are readily available.

The latest 'Flight International' which has just dropped in to my 'inbox' has a half page article on the incident, most interestingly citing Emirates now introducing a second laptop on the flight deck, to perform independent performance calculations. Obviously their SOP was not to have two laptops.

My point exactly, as per my previous post!

Surely it is better to get the dispatcher who prepared the loadsheet to do the perf calcs ?

Then you have two completely separate, independent data sources for v figures.