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Wrong weight entry again

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Wrong weight entry again

Old 8th Jul 2010, 13:50
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Wrong weight entry again

I would have put it at the end of EK407 Tailstrike @ ML but this is now closed.

Virgin A340 take-off miscalculation defeated 'robust' checks

... did they "quit" their job this time ?
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Old 8th Jul 2010, 14:14
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This commercial fascination that some airline's Flt Ops departments have with these laptops and optimized take-off performance are really kind of a sad joke.

It's picking fly shit out of pepper.

At a former carrier we had a system where we sent runway and weather info via ACARS and we got a piece of paper back with the speeds on it. We entered the speeds in to the MCDU and away we went. That carrier has been operating FBW Airbus since they entered service in about 1988 and to my knowledge there has never ever been a single entry error for take-off weight. No laptops - they are bullshit imho. Somebody elses idea of a clever way to introduce a lot of work for very little return and the potential for huge errors with potential for catastrophe.

It's a little bit like management's non-response to fatigue reports.

HOW MANY DO YOU HAVE TO HAVE BEFORE YOU SEEK A SOLUTION?

WHY DID YOU NOT SEEK CHANGE AFTER THE FIRST INCIDENT? What are you waiting for, exactly? I'd love to know. I really would.

There's much to be done, let's get at it.
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Old 8th Jul 2010, 14:54
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wrong entry

interesting how one can enter ~100t erroneously. it's like not knowing your own shoe size. monkey see monkey do
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Old 8th Jul 2010, 15:04
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How can a pilot not know just by looking at his FOB/Pax count/Belly load what his GTOW is within a few hundred KG? Is nobody giving the V speeds a "smell test"? ie, does this smell OK? The last one like this I heard about was two management pilots who didnt think that 45kts between V1 and Vr smelt a little fishy {normall max on this aircraft 11kts max} The result, a badly bent tail skid. Time to get back into the loop and have a good handle on roughly what the GTOW should be given the load and fuel.
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Old 8th Jul 2010, 15:08
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Thinking with the eyes

Up to the 1960s in the UK old ladies out shopping would deal in pounds, shillings and pence with an astounding mental agility.

Lucky for them they didn't have a machine to tell them the right answer. Now people prefer to think with their eyes, reading the result, rather than with their brains.

Are we surprised these things happen?
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Old 8th Jul 2010, 15:08
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Having used the VS system of Aircraft Performance, abided by their SOP's and operated for the airline....I can say that this is a rare occurence in VS.

It really sounds to me that there was a breakdown in VS SOP usage on this isolated incident. Simple as that. The crosschecks were ignored/bypassed/not used.

As for Laptop/Computerised speed systems. Well, this is a SORT OF computer system. It is driven through the ACARS system onboard.

I now use a pure Laptop performance system and I must say, it works very well.

But like anything computerised.... Put rubbish in, get rubbish out.

You need to know what you are looking for.
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Old 8th Jul 2010, 15:15
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Re., wrong entry

Why the error? Its called MFF(Mixed Fleet Flying). Virgin have both A340-600
MTOW 368 tons, and A330-300 MTOW 275 tons. You see jackx123 its roughly 100 tons difference in weight of the two types. So, yes it has happened in the past and will probably happen again in the future. When you sit in the cockpit they are very similar, hence the MFF.

Fjordviking
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Old 8th Jul 2010, 15:35
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I've said it before and I'll say it again, why does the loadsheet not have V-Speeds on it, it would give an additonal cross-check. Seems simple really.
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Old 8th Jul 2010, 16:24
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so what happened with the crew?
taken in and debriefed, or asked to leave??
 
Old 8th Jul 2010, 16:56
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Does Virgin use licensed dispatchers?

Someone mentioned putting V-speeds in the loadsheet, but that can only be done if other performance factors are done by someone else before the loadsheet is passed on to the crew.

Most major airlines in the US get their performance data from their dispatchers and plug it in. Maybe this helps to add redundancy to the system in that you have an extra set of eyes removed from the cockpit.

I'm not saying the American system is perfect, but I can't think of any such failures with regards to TO performance errors like this VIR and UAE incidents. I know that many dispatchers in the US are licensed pilots, and I would much rather have more human safety systems in place than another computer system.

A new computer safeguard would only take us to the next weakness, and then we'll be debating the next computer safeguard. All I'm saying is let's bring the human aspect back.
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Old 8th Jul 2010, 17:28
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the UK's Air Accidents Investigation Branch states that the crew, pushed for time, skipped the normal procedure which required them to estimate the take-off weight, and use this to crosscheck actual data.
It's nothing to do with laptops or "knowing" what the Vspeeds should be, it is simply a crew not following robust procedures and reaping the consequences.
If you don't find the time to do it right, how will you ever find the time to do it again?
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Old 8th Jul 2010, 17:57
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Originally Posted by fjordviking View Post
Why the error? Its called MFF(Mixed Fleet Flying). Virgin have both A340-600 and A330-300
[...]
When you sit in the cockpit they are very similar, hence the MFF.
Surely the number of donks on each wing would give just a small clue in this case ?

Or do you just walk down the airbridge into the cockpit without ever looking at the outside of the plane these days ?
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Old 8th Jul 2010, 18:09
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Originally Posted by M-rat
At a former carrier we had a system where we sent runway and weather info via ACARS and we got a piece of paper back with the speeds on it. We entered the speeds in to the MCDU and away we went. That carrier has been operating FBW Airbus since they entered service in about 1988 and to my knowledge there has never ever been a single entry error for take-off weight. No laptops - they are bullshit imho. Somebody elses idea of a clever way to introduce a lot of work for very little return and the potential for huge errors with potential for catastrophe.
The VS incident was via ACARS and not laptop - read the AAIB report

Originally Posted by ex cargo clown
I've said it before and I'll say it again, why does the loadsheet not have V-Speeds on it, it would give an additonal cross-check. Seems simple really.
Loadsheet is from load control - they have bugg#r all to do with performance calculations.. And there are so many variables - it's not like a turboprop or small jet where you can just pull a booklet out and flip to the relevant take-off flap and weight page.. Performance calculations should be SOLELY up to the crew!!! Just be careful with your numbers and don't rush...
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Old 8th Jul 2010, 18:11
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Originally Posted by infrequentflyer789
Quote:
Originally Posted by fjordviking
Why the error? Its called MFF(Mixed Fleet Flying). Virgin have both A340-600 and A330-300
[...]
When you sit in the cockpit they are very similar, hence the MFF.
Surely the number of donks on each wing would give just a small clue in this case ?

Or do you just walk down the airbridge into the cockpit without ever looking at the outside of the plane these days ?
See how easy a typo is? Fjordviking means VS fly 340-600 and 340-300 (not 330-300). Same number of 'donks' on each wing infrequentflyer789..
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Old 8th Jul 2010, 19:05
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Just a techy update on this, both Honeywell and Thales, the FMS suppliers for Airbus are working on versions of their FMS systems in which one of the improvements will be a feature that secures take off performance. It basically introduces a rough error check to prevent such large errors being entered into the FMS.

I think both are due for certification next year and whilst newer aircraft it will involve just software updates some slightly older FMS installations will require some hardware and the software changes and on the really old Airbus FMS systems a complete retrofit of the system will be required.
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Old 8th Jul 2010, 19:36
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@ fjordviking

Code:
Virgin have both A340-600 MTOW 368 tons, and A330-300 MTOW 275 tons
That's really troublesome that the Pilots in this case cannot tell the difference between 346 and 333
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Old 8th Jul 2010, 21:43
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@Jackx123

@ fjordviking
Code:
Virgin have both A340-600 MTOW 368 tons, and A330-300 MTOW 275 tons
That's really troublesome that the Pilots in this case cannot tell the difference between 346 and 333
Like White Knight alluded to earlier, Virgin don't have A330s. It was a simple typo!
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Old 8th Jul 2010, 21:51
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FWIW:

we knew how much fuel (pounds), how many people (which we multiplied by 200 pounds) and the BOW (basic operating weight of the plane). So, in our humble minds we put them all together. Then we flipped our little vspeed FLIP BOOK to the weight we came up with. We set our tri to the green band...just guessing mind you and we waited.

Across the ACARS came the W&B calculations, v speeds, trim, optional reduced power and runways.

Our flip book was already set to the right weight...it was a nice little system...(the pax times 200 took care of belly luggage)
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Old 8th Jul 2010, 22:00
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Just to clarify, Virgin use an ACARS system to calculate the required speeds prior to takeoff. This system is provided to them as a partnership of SAS and Navtech.

It provides a few screens to input data on the MCDU and then it is transmitted to a server by ACARS and then the results are sent back.

The system is also available on the Internet for use in the event ACARS is U/S. It is not a laptop based system.

PT6A (below is a sample from the ACARS)

G-VFOX 08JUL10 22:04 V3.3.6
A340-642
EGLL/27RFULL

000/00 +15C 1013
DRY RUNWAY
RW 3884 CW 77 SW 0
AC-OFF A/I-OFF
SYST OK


CONF 2 FULL THRUST
CLIMB 400.0
OBSTACLE 400.0
FIELD 400.0
STRUCTURAL 368.0

ACT TOW 360.0
MAX FLEX T=48
V1 - 149
VR - 168
V2 - 179
ACCL ALT STD 1600FT

NOTE:


TODC END
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Old 8th Jul 2010, 22:36
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I'm with TyroPicard.

This is not a computer problem. This is not an Airbus problem (it has happened on Boeing too; SQ B744 at Auckland in 2002).

I'd even go so far as to say it is not a mixed fleet flying problem.

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).

Get back to basics, and focus clearly on the task at hand.
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