Airline software super-bug: Flight loads miscalculated because women using 'Miss' were treated as children
- Reference: 1617909240
- News link: https://www.theregister.co.uk/2021/04/08/tui_software_mistake/
- Source link:
The error occurred, according to a report
[1]PDF
released on Thursday by the UK Air Accidents Investigation Branch (AAIB), because the check-in software treated travelers identified as "Miss" in the passenger list as children, and assigned them a weight of 35 kg (~77 lbs) instead of 69 kg (~152 lbs) for an adult.[2]
The AAIB report attributes the error to cultural differences in how the term Miss is understood.
"The system programming was not carried out in the UK, and in the country where it was performed the title Miss was used for a child, and Ms for an adult female, hence the error," the report says.
[3]
The Register asked TUI where the system programming was done, but the company ignored that question in its response to our inquiry.
"The health and safety of our customers and crew is always our primary concern," a TUI spokesperson said in an emailed statement. "Following this isolated incident, we corrected a fault identified in our IT system. As stated in the report, the safe operation of the flight was not compromised."
Potentially fatal math
Flight load miscalculations have the potential to affect aircraft handling and to create serious safety issues: the figures are used for figuring out fuel levels, altitude, takeoff thrust, and so on. The 2018 fatal crash of Cubana de Aviación Flight 972, for example, has been [4]attributed to excessive load , as has the [5]1997 crash of Fine Air Douglas DC-8 cargo flight.
According to the AAIB, the software issue was first spotted on July 10, 2020, when three adult passengers identified as Miss were checked in as children. Airline personnel caught the discrepancy and proceeded to make adjustments manually.
US aviation regulator issues safety bulletins over flaws in software updates for Boeing 747, 777, 787 airliners [6]READ MORE
On July 17, the developer(s) working on the check-in application "adapted a piece of software, which changed the title of any adult female from Miss to Ms automatically."
Alas, the revised code could only convert honorifics for passengers prior to check-in. Bookings made with the title Miss that had already checked in, including those checking in online 24 hours prior to departure, could not be changed.
"On 20 July, 2020, the programmer was making enhancements to the program to improve its performance," the report says. "This should not have stopped the program from working, but as this was a 'fix,' it could not be known for sure. A combination of the [TUI] teams not working over the weekend [to make manual corrections] and the 'online' check-in being open early on Monday 20 July, 24 hours ahead of the flight, meant the incorrectly allocated passenger weights were not corrected."
On 21 July, 2020, three TUI Airways flights departed from the UK with inaccurate load sheets as a result of the software issue, which would not be fixed until July 24, 2020.
The first of these, and the only one detailed in the report, was TUI Airways flight BY-7226, a Boeing 737-800 with the registration G-TAWG. The plane travelled from Birmingham International Airport in the UK to Palma de Mallorca in Spain, carrying 167 passengers and 6 crew.
The 737-800 departed with a takeoff weight that exceeded the load sheet (the projected weight) by 1,244 kg (~2743 lbs) because the load sheet listed 65 children on board, compared to the 29 children expected from the flight plan – which includes the actual weight. The load sheet also varied from the flight plan due to errant baggage weight calculations.
The result of all this was that the plane used less thrust to take off than it should have – 88.3 per cent instead of 88.9 per cent given its actual takeoff weight and environmental conditions. Fortunately, this was "marginally" more than the minimal regulatory requirements – 88.2 per cent – and the flight made it to its destination safely.
[7]
It's suggested this won't happen again: "An upgrade of the system producing load sheets was carried out to prevent reoccurrence," the report concludes. ®
Get our [8]Tech Resources
[1] https://assets.publishing.service.gov.uk/media/604f423be90e077fdf88493f/Boeing_737-8K5_G-TAWG_04-21.pdf
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/applications&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YG99MbvzvAfOHI0YKEoGWwAAAM0&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/applications&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33YG99MbvzvAfOHI0YKEoGWwAAAM0&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[4] https://en.wikipedia.org/w/index.php?title=Cubana_de_Aviaci%C3%B3n_Flight_972&oldid=1009327744
[5] https://admiralcloudberg.medium.com/out-of-balance-the-crash-of-fine-air-flight-101-db484c84e4e6
[6] https://www.theregister.com/2020/12/16/boeing_software_updates_faa_warning/
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/applications&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YG99MbvzvAfOHI0YKEoGWwAAAM0&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[8] https://whitepapers.theregister.com/
Not necessarily.
If those were all children that'd be one thing, but if they were all pro sumo wrestlers then the plane might not have ever left the ground!
Re: Not necessarily.
".. but if they were all pro sumo wrestlers then the plane might not have ever left the ground!"
Almost happened to a friend of mine, years ago. She picked up a full load of passengers somewhere in Oceania and then had great difficulty taking off. Later when she walked through the cabin she realised they were the local rugby team - which explained everything. I also noticed in one of my aviation books that the average passenger weight for folk in this region was rather higher than elsewhere.
Another friend was a bush pilot in Australia. He landed at a mining site somewhere in the outback, told the local crew they could load the plane up with X pounds of ore samples and went to have lunch. He too had great difficulty taking off. Eventually he realised they'd loaded his plane up with X kilos of samples. After that he made quite sure he communicated the payload weight more clearly.
Have a safe flight.
It's not pretty pointless, It's very pointed.
Just because you are not affected this time doesn't mean you couldn't be in the future.
Stop thinking about just yourself and try and grasp the possible effects of this error.
It seems people were doing their jobs diligently so well done to them, and the way they had been trained.
That's how aviation is supposed to work.
There are many vital links in the chain, the pilots are the most visible in any enquiry of course.
But pilots can only deal with what is in front of them and they rely on the supply chain being accurate.
TUI failing to respond to the specific question El Reg asked about where the system programming is interesting, I think I'll ask them that question myself and see if I get a response.
Who was the developer?
It can't have been Boeing because the pilots were able to override the issues.
So you're a pilot
Once upon a time the pilot of an aircraft would have to be responsible for a pre-flight check including air-worthiness of the plane, knowing takeoff weight, fuel amount, and maintenance history. They would also have to submit a flight plan. All before takeoff. It was part of being a pilot, and not necessarily anything to do with knowing how to actually fly the plane in the air. Several disasters later we know that its simply not possible anymore for the pilot to gather all the info they need to know. So its then the responsibility of the airline to ensure that the required checks have completed and information is accurate. Pilot error is often attributed when things go wrong, but it should be obvious from the above that modern pilots of larger aircraft are completely blameless when things like takeoff weight are wrongly calculated.
11 stone..
Seems a touch optimistic for the average weight of a woman on a TUI flight out of the UK....
Re: 11 stone..
Seems a touch optimistic for the average weight of a child on a TUI flight out of the UK....
Re: 11 stone..
It's a touch optimistic to expect any opinion about a woman's weight would be deemed not worthy of raising. Facts on the other hand are a different matter.
Re: 11 stone..
a women's weight, a woman's height, a man's height...
No opinion, because I'd rather point towards the history of collecting data to create averages for chunks of the population. Fascinating slices of life.
From the USA gov needing to know what size of military uniform to produce informing our current S M L XL labels, to percentile of pop height range a car driving seat must accommodate... and doubtless many edyfying case studies I've not read.
It is odd that many folk of average height (for their group, obviously) in the UK ( c. 6") are sold duvets that ask them to choose between warm toes and chilly shoulders, or vice versa.
Re: 11 stone..
Should just have a field for customer weight. I'm sure all the Miss and Ms will fill it out honestly.
Re: 11 stone..
I'm really curious as to why they don't use passenger age to determine whether they are a child or not? It's on your passport, after all, and airlines do flog child tickets...
Full steam ahead
Maximum power!
Re: Full steam ahead
& we all remember how well that worked out for Servalan.
SFW: https://imgur.com/hyXGuqv
Does that mean it was a serious misstake?
Serious misstake
Either that or a serious mstake.
"the company ignored that question"
Not acceptable.
You do not program for how your own country interprets values. You program for how your client country interprets values.
Mistakes like that lead to [1]losing a satellite because you transmitted data in metric values while the program treated them in imperial values.
[1] https://en.wikipedia.org/wiki/Mars_Climate_Orbiter
Re: "the company ignored that question"
WTF is wrong with using DOB to calculate child / adult for weight estimates?
Re: "using DOB to calculate"
No thumb, because it's a reasonable question. I don't think that information is provided by passengers. The fare code used for children under a certain age that travel free "on lap" might be applicable, but only covers the very small.
Bender Rodriguez...
...you are under arrest. You are charged with
Depriving children of food
Selling children as food, and
Misrepresenting the weight of livestock
Re: Bender Rodriguez...
Never sell children as food.
They're only worth by the pound that way. Always sell whole, on eBay, before their 1st birthday when their value declines.
Re: Bender Rodriguez...
I like children, but I could never eat a whole one.
Little Miss Sunshine
"The health and safety of our customers and crew is always our primary concern," a TUI spokesperson said
Really? Because it sounds like the cost of software development is your primary concern.
I would have thought...
...that normally on takeoff, the pilot would be using everything short of War Emergency Power, throttles to the stops. I would hate to clip an obstacle at the end of the runway because the airline was trying to save a few bob's worth of fuel, and the passenger cohort had more than the normal fraction of bloaters.
Every day's a school day.
Won't nobody think of the test cases?
I'm guessing there was either no test cases, or the calculations made on the list of passengers in the test case repeated the same error.
"It's suggested this won't happen again"
What won't happen again?
This particular problem - maybe not now it's fixed unless, of course, somebody reverts to an older version or looks at the new code and thinks "That's not right for a child"?
Or developing against an insufficiently detailed spec that assumes culturally specific knowledge on behalf of the developer?
The system programming was not carried out in the UK, and in the country where it was
performed the title Miss was used for a child, and Ms for an adult female, hence the error.
A manual solution for correcting the problem was quickly identified that involved a team
identifying upcoming flights, checking each booking, and changing all adult females with
the title ‘Miss’ to ‘Ms’, which overcame the problem. Subsequently, this work was shared
between two teams, and the process was completed every afternoon and evening for the
next day’s flights. It was checked again every morning, where possible, before flights
departed.
Pretty pointless at the moment. 27 passengers in a dreamliner on my flight on Monday.