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Wrong weight entry … again

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Old 9th Jul 2010, 00:38
  #21 (permalink)  
 
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This is a problem with crews not having a rule of thumb, or gross error check in their heads. To me, that shows a lack of awareness of your aircraft, and far too much reliance on automation (of all types).

Getting the figures done by someone else (load controllers, dispatchers etc) is not a solution, it is merely an attempt to shift the blame in the event of error (they are human too).
It is not that simple Chimbu. Have you considered that maybe the procedures are so complex and attention-grabbing that no-one has any extra capacity to catch gross errors. Have you ever seen the video with the people passing a basketball around and you have to count the bounces and passes? It is a really good example of task saturation and how you can miss the "elephant" in the room.

And I'm not suggesting to include others in order to apportion blame but merely to have someone else with different set of distractions as a safeguard.

I'm merely asking has this type of incident occurred at a carrier with a dispatcher system in place, or does it at least happen less frequently? Only trying to find a solution. "Just don't do it again" type solutions have been proven to not work - otherwise we would still be flying around with long memorized checklists, no GPWS, and no gear warning systems.
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Old 9th Jul 2010, 01:14
  #22 (permalink)  
 
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I dunno,

It happens once, I'll call it pilot error.
It happens two or three times, I'll squirm a little and still call it pilot error.
It happens five times, I'll start to question pilot error.
It's happened more than that. Maybe, just maybe there's a problem here.

Now you all understand, I've never made a mistake in an airplane.


The Goldfish
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Old 9th Jul 2010, 06:32
  #23 (permalink)  
 
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Pilots

So the question is: How does one become a captain? Hmmmm can it be experience

Well let's assume it is experience how the F**K can't you tell 100t difference.

Say the a/c burns 7-8t per hour and you should at least have a vague idea where you're flying to and the time it takes. Is it 2h or maybe 10h? Oh no just go ahead and blame it on some box in the middle - very amateurish that may cost human lives
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Old 9th Jul 2010, 06:50
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Have to agree with M Rat,


These laptops and their use to compute take off performance in the cockpit under tight time constraints seems to be a consistent weak link and an accident waiting to happen.


Especially with Crews operating similar types with significant gross weight differences.


In the US, most Major Airlines including the one I work for have dedicated 'load planning' departments that compute the take off numbers then data link them to the FMC.


After double checking the numbers for reasonableness we then accept and load them into the FMC.



It's been a pretty good system with the advantage of using a dedicated department of load planning specialists (with double checks of their own) in a spacious environment working with a lot more than a laptop balanced on their knees with a few minutes to push..



It seems a little ironic, that with all of the emphasis on performance in the theoretical examinations for the UK and JAR licences that under that system most of these disastrous take off miscalculations have been made.


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Old 9th Jul 2010, 06:56
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Is this misinformation or disinformation? A Virgin crew succumbing to such mistakes? The way I hear from the expats over at KAL, it can never happen because they are such astute operators. It can only happen in KAL, Dynasty......Virgin, EK, CX? .........never!!! Must be some kind of sick joke or wind up.
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Old 9th Jul 2010, 07:01
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Weight on wheels.How much?

Understand weight of the airplane ascertained by calculations and checked against calculations. Nobody looking at the actual physical thing.

Actually undercarriage is a very large scale , isn't it?

Coat,hat and hangar . Hello Mr. Pierrepoint.

Last edited by wetbehindear; 9th Jul 2010 at 07:37.
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Old 9th Jul 2010, 07:17
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Just look at some of the people posting on here! You've got the likes of jackx123 who is spouting off and quite obviously has no conception of operating a heavy type such as the A340 but takes it upon himself to preach about rules of thumb and gross error checks.

Obviously he is trying to relate his experience flying something older and much lighter without having read the AAIB report. What can we expect next? Advice on cross controlling the A340 for crosswind landings?

Also, there is all this hand wringing and tut tutting from various posters who, again, show themselves to be inexperienced in the operation of modern heavy jets but are quite prepared to cast blame and unwanted advice to those of us who do operate these aircraft. There are even spotters who mistakenly think the crew operate the A340-600 and the A330-300 when it is the fact that they operate the A340-300 and then we are preached to about "counting the number of 'donks'" to avoid the kind of error we are supposedly discussing!

Why can't you read the article and AAIB report and then discuss without all this amateurish speculation based on some ignorant Muppets getting the facts wrong. For example, where does it state that they used laptops to calculate their performance figures? Well, it doesn't because they didn't and Virgin don't.

The report states that the crew did not stick to SOP and this lead to the error not being spotted. No matter how "robust" the procedures are, not sticking to SOP can lead to this situation. Additional factors were mixed fleet flying between the bigger and heavier A340-600 and the smaller and lighter A340-300 as well as distractions and other pressures during a rushed preparation.

Can we please have the amateurs and others inexperienced in the operation of heavy jets stick to 'informed' observation rather than their presumptions and criticisms based on their anonymity and wet dreams of being a heavy jet pilot. Gross error checks are part of the normal SOP but in this case they weren't followed which allowed a gross error to get into the system. No laptops were or are used at Virgin as it is an FMC/ACARS system and if you don't know what that is then you shouldn't be commenting on here as it just shows you to be a wannabe wet dreamer!
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Old 9th Jul 2010, 07:29
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We fly A332/A333/A345/A346 as MFF and there are a lot of weight differences and ranges, including speed and the cockpits look very much the same, including 500 and the 600. That being said, I know of a few cases where the correct weights have been calculated, but incorrect fuel has been uplifted which is also a problem. Example, pilots uplifted 43.8 tons instead of 48.3 tons, a difference of almost 5 tons (an hours flying in A330) short. Speeds were good, but fuel was wrong!

In another case pilots have uplifted trip fuel instead of flight plan fuel on the A320, only to have an embarrassing chat to ops about where to land enroute for a technical stop.

The list goes on and on and all the mistakes have slipped through the system design to catch it, but it didn't. Human Factor is a natural problem, which makes us infallible. We need to slow down and have time catchup with us!

Most companies require pilot to individually calculate the take-off figure and then compare the figures, including the green dot speed. But when chased for time, we work over the other guys shoulder, cross communicating the weights being used or weather and hence we are doubling up on the wrong information and will have a problem.
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Old 9th Jul 2010, 07:46
  #29 (permalink)  
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The report for those who wish to read
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Old 9th Jul 2010, 07:52
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Heavy operator

Thanks for calling me spotter. Like whiteknight pointed out, typo on the A330-300, meant to write A340-300.
Having flown a meager 6000 hrs on the A320/A330-200/A330-300/A340-300/A340-500, having done the MFF/CCQ on all the variants I know it`s not that easy always to have that built in warning lamp in your head come on when an unusual number pops up for one type. That number was perfectly valid on the type you flew on your previous sector.
I`m human, I do make mistakes, but luckily most of them do get trapped.

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Old 9th Jul 2010, 07:57
  #31 (permalink)  
 
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Automatic xcheck and warning

Answer to the problem = An automated Xcheck. We cannot go back to the RTOW paper charts so why not make the best usage of automation.

The computer system used, either a cockpit BLT/LPC/OIS or that used via ACARS needs to have a sub routine working in the back ground. This routine should know the usual average TOW for the airlines sectors (a simple summation program) and if there is a significant variation to that on the day then display a warning screen. This would advise the crew of a possible error, to recalculate their TOW again and reinsert/send the revalidated data (ZFW, TO Fuel, etc).
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Old 9th Jul 2010, 08:15
  #32 (permalink)  
 
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I believe that there is more to this incident that what is being told...

The VS SOPs for performance are pretty rigid and idiot proof if you follow them, strict adherence to them was highlighted after a couple of incidents in the past...
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Old 9th Jul 2010, 09:16
  #33 (permalink)  
 
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Just be careful with your numbers and don't rush...
Another thread has questioned whether we rely too much on computers, it doesn't matter if you call them FMC, ACARS etc. same problem.

One of my early Flt. Nav.instructors told me to stop trying to do a maths exam in a rattling steel cabinet, i.e. Big Numbers, Rule of Thumb, then refine as necessary, it's like using an old style Slide Rule ( remember them ? ) one had to know where to put the decimal point,i.e. have a pretty good idea of the answer before asking the question.

Think navigation has nothing to do with this ? same philosophy, check, then re-check, ( and on the Stratocruiser the navigator worked out the take-off calculations anyway ! )

It all comes down to the fact that Mr. Murphy is always with us.
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Old 9th Jul 2010, 09:19
  #34 (permalink)  
 
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These three stand out
1) Rushed for time
2) Sluggish, Lowered the nose. TOGA??
3) Airbus. Designed by engineers for engineers.
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Old 9th Jul 2010, 10:04
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and one more... fact that landing weight inserted into TOW field.
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Old 9th Jul 2010, 13:41
  #36 (permalink)  
 
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Answer to the problem = An automated Xcheck. We cannot go back to the RTOW paper charts so why not make the best usage of automation.

The computer system used, either a cockpit BLT/LPC/OIS or that used via ACARS needs to have a sub routine working in the back ground. This routine should know the usual average TOW for the airlines sectors (a simple summation program) and if there is a significant variation to that on the day then display a warning screen.

Such a system exists and is operational at the airline I work for. It's even better: it compares the TOW that's inserted into the (ACARS-based) performance system with the last known TOW in the loadsheet-system. If the difference exceeds certain thresholds, a warning is added to the message.
No system is gonna be foolproof, but this seems like a fairly straighforward way to catch this kind of error.

Last edited by MoodyBlue; 9th Jul 2010 at 13:48. Reason: Typo
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Old 9th Jul 2010, 15:14
  #37 (permalink)  
 
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jackx123
wrote:
So the question is: How does one become a captain? Hmmmm can it be experience

Well let's assume it is experience how the F**K can't you tell 100t difference.
I'm gonna go out on a limb here and guess that you don't fly commercial airliners. Am I right?
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Old 9th Jul 2010, 15:45
  #38 (permalink)  
 
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Forty years ago, BEA (as it then was) converted some of their Vanguard 4-turboprop airliners into Merchantman freighters.

Part of the conversion refit included fitting mass transducers into the three landing gear legs. During pushback, a switch was operated which gave a read-out of TOM (masses summed) and CG position (main gear sensed masses compared to nose gear sensed mass).

On at least one occasion the system saved an embarrassment (or worse) when the pallets had been loaded in the reverse order compared to the load sheet, giving a CG outside the permitted envelope.

Could not mass transducers be fitted in today's aircraft, with the sensed total mass data inputted directly to the FMC? Gross errors would show up immediately.

Last edited by Discorde; 9th Jul 2010 at 15:55.
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Old 9th Jul 2010, 16:59
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Such sensors have been built in to modern aircraft as well, but have been deactivated as airlines found the sensed weight would often be considerably over the load sheet weight.......
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Old 9th Jul 2010, 17:49
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Safelife said.....................
"Such sensors have been built in to modern aircraft as well, but have been deactivated as airlines found the sensed weight would often be considerably over the load sheet weight......."

Surely you jest, Sir.
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