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TUI planes takes off 1200 kg overweight after software error

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TUI planes takes off 1200 kg overweight after software error

Old 9th Apr 2021, 22:23
  #21 (permalink)  
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The TUI B737 was overweight for the performance figures used, meeting the requirements at its actual weight could involve different speeds and power settings.

An aircraft is required to be operated within its certification limits, go outside those and you become a test pilot. Center of gravity comes into play as well if you are overloaded, particularly in the event of an engine failure. If an accident occurs, the loadsheet is one of the first things to be checked and the insurance company will be looking for an excuse to get out of paying.

A while back, I was a pax on an ATR42 operating out of a limiting airport and everyone had to stand on the scales during check in. The take off involved stopping on the runway and powering up against the brakes so I was quite happy to know that the pilot was working with actual weights.
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Old 9th Apr 2021, 22:41
  #22 (permalink)  
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And yet the fuel gauges are only required to be accurate to +/-2%, which is quite a lot on a large aircraft...
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Old 9th Apr 2021, 22:49
  #23 (permalink)  
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Originally Posted by GlobalNav View Post
Is it a “software error”? Or is it a software “user error”?
The former.
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Old 9th Apr 2021, 23:42
  #24 (permalink)  
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According to the report, a software error: the software was written in a country where "Miss" is only used of children (does anyone remember when boys were called "Master"?) Presumably not in fact the English word "Miss" but a word in some other language which kind of half translates to "Miss." A subtle example of the perils of outsourcing, if this was the cause.
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Old 10th Apr 2021, 22:53
  #25 (permalink)  
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Given the increasing use of software/firmware in various aspects of the transport fleet today (not just aircraft) I think this is the most important point to have come out of this incident.

What is worrying to me is that the country in which the software was written is not identified in the report. If a report is to have validity, and to be of some use in preventing future incidents or accidents, then I would expect full disclosure on causal factors.

As this report rests at the moment, if I was relying on software for a critical task 'written in a[nother] country' I'm still none the wiser as to whether I should be checking/expecting such errors to occur. If I was charged with conducting the 'initial risk analysis' on a system for example I'd like to have a headsup as to whether this is an area I should consider at increased risk of error should the software/system originate from say, Norway, India or Russia for example?

The following excerpt from the report shows what I consider to be a deficiency in the report and which could itself lead to further non-identification of risk factors (my underlining):

"The incident occurred due to a simple flaw in the programming of the IT system, which was
due to the meaning of the title ‘Miss’ being interpreted by the system as a child and not an
adult female. This was because in the country where the system was programmed, Miss is
a child and Ms is an adult female. This issue had not been identified as part of the initial risk
and did not manifest itself during the trial simulations."
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Old 10th Apr 2021, 23:04
  #26 (permalink)  
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Can I just add, acknowledging that I am not a professional of aviation or data processing, that I am surprised and worried that an item like the passenger weight allowance should be automatically filled in from the honorific? I mean, Dr, Prof., the Revd--these immediately leap to mind as being non-gender specific honorifics in common use in Anglophonia, just for starters.
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Old 11th Apr 2021, 03:57
  #27 (permalink)  

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Bullseye! The weight context for passengers per regulation is based on age. The system has the birthdate and should label/populate the passenger element accordingly. Using "titles" is plonkers of a job at the SW definition phase, regional customs or language notwithstanding.

And the proper ones do. I ran once into an issue of an infant turned child between the check-in time and loadsheet closure. Partly for us being late and it has become a substantial headache on a full flight. Tirana in Albania it was.

As long as some are looking to point fingers, perhaps it's the business choice of TUI not to use proper industry-grade systems which deserves the attention. Or (to demand and pay for) proper aviation-style validation procedures, i.e. white-box testing.

Last edited by FlightDetent; 11th Apr 2021 at 07:08.
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Old 11th Apr 2021, 19:29
  #28 (permalink)  
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The problem is not so much which country might have been involved - it really shouldn't matter - the initial risk analysis should be done by the system owner/operator, in this case, the airline. Secondly, the fact that the problem did not manifest itself during the trial simulations simply means that the test schedule was incomplete and inadequate. Both issues should be managed by the system owner, even if the work is done by another agency.

Notwithstanding that, in this instance, the impact on the flight was insignificant, particularly given the approximations and other inexactitudes involved in loading calculations, the potential for a more serious event to occur as a result of similar process failures should be of concern.
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Old 11th Apr 2021, 23:01
  #29 (permalink)  
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Many years ago doing a 1hr sector to a holiday destination in a 321, lots of passengers that “enjoyed” fast food and free carry on luggage.

At transition (10,000ft) a quick calculation of the FOB + Fuel Burn and all was well, but then I glanced at the GW on the Lower screen.

Recalculating the numbers, FOB+FB+ZFW= 1.8 T more than an our Calculated TOW. Our projected LW was only 1.2T less than our Calculated TOW for a 3T burn.

So, the FAC calculated GW was 1.8T higher than the Calculated TOW??? The Alert for incorrect data entry only happens at ~7T

At the time we were still using the paper T/O tables, so lots of factoring was built in, especially by the crew, thankfully.

I reported it to the company, there was an investigation. Changes were made and shortly after the weight used for Males and Females was changed to be the same, 83kg.

The 83kgs includes 7kg of carry on, bags were checked for weight and size with the heavier/larger bags going underfloor at a very exorbitant charge. This has become a very profitable revenue stream.

I look at the pax sometimes and wonder if this is enough. I’m 5’7” (172cm) and am 80kg, there are a lot bigger people than me.

The company continued to have issues with the boarding programs and had more incidents of incorrect paperwork being ACARS’ed to the aircraft. Ie: one flight took off with 150 on the manifest, but actually had 180 onboard.

Major errors were found with the boarding system, it took more than 12 months to sort it out, and we still have to conduct a headcount about 4/10 flights because they can’t seem to get it right.

I noticed our newer CEO’s don’t have any mention of this FAC calculation post take off in the manuals, but still mentions it for Approach speed calculations.

On the Wide body, summer/winter weights were scrapped, as were “Asian” weights, as it was found our pax were predominately Anglo and had maximum carry on.
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Old 12th Apr 2021, 08:46
  #30 (permalink)  
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Does the aviation industry not have software engineering standards ?
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Old 13th Apr 2021, 01:49
  #31 (permalink)  
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The bean counters will tell you that would be far too expensive.
I'm sure they would rather just use much cheaper development techniques for aircraft-control systems, too, but the certification authorities won't let them for some reaaon.
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Old 13th Apr 2021, 07:38
  #32 (permalink)  
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What is this country?
Does anybody know?
India? Australia? Jamaica
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Old 13th Apr 2021, 14:11
  #33 (permalink)  
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If it was Swissport, I believe their load sheets are generated in Morocco or Kenya.
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Old 13th Apr 2021, 16:49
  #34 (permalink)  
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I believe the 64k question, unanswered, is where was the software upgrade written.
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Old 13th Apr 2021, 17:52
  #35 (permalink)  
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We often used "all adult weights" or "standard charter weights " which came close to 76KG an adult, probably so the baggage could be "legally loaded"! Looking at some of the Arab country and German pax, 70KG for a female was about half right and the male weight was ludicrously low. On 280 pax we could have early been 3000 KGs out, but as long as we showed an underload no one gave a hoot. The thrust difference on this flight was the width of a fag paper.
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Old 13th Apr 2021, 18:51
  #36 (permalink)  
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Cross check

Given it seems to be pretty simple to cross check the actual weight from performance data when in cruise why not make a point of recording that in flight number and comparing it to the number entered on the ground.
Pretty quickly the operators would be able to see if pattern exists. Flights from certain locations, time of year - winter ski season comes to mind.
Also be a good way to catch software and provider busts.
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Old 14th Apr 2021, 00:09
  #37 (permalink)  
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The bags get weighed, the carry on too here, why not weigh the pax? It does happen in some areas of aviation and never seen anyone object.
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Old 14th Apr 2021, 02:56
  #38 (permalink)  
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Old 14th Apr 2021, 03:45
  #39 (permalink)  
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Standard weights for pax are reviewed regularly and can be overridden by the loadsheet agent, a common example during training was if a group of Sumo wrestlers were travelling.. even here the crreection that you applied was an estimate. A colleague working for another airline which had a high traffic of Indonesian female workers (quite petite) applied for, and was granted a lower standard passenger weight for that sector. This resulted in more payload available for cargo.

When I worked for LH, the weights for short haul flights were higher than for long-haul, the rationale was that short-haul pax tend to have hand-carry luggage so this was factored in.
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Old 14th Apr 2021, 06:36
  #40 (permalink)  
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AMC2 CAT.POL.MAB.100(e) states procedure on how to establish standard passenger weights
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