In Serious Incident, Software Glitch Miscalculates the Weight of Three UK Flights (theguardian.com) 93
A software mistake caused a flight on Tui airlines "to take off heavier than expected," according to The Guardian, citing an investigation by the UK's Air Accidents Investigation Branch
An update to the airline's reservation system while its planes were grounded due to the coronavirus pandemic led to 38 passengers on the flight being allocated a child's "standard weight" of 35kg [77 pounds] as opposed to the adult figure of 69kg [152 pounds]. This caused the load sheet — produced for the captain to calculate what inputs are needed for take-off — to state that the Boeing 737 was more than 1,200kg lighter [2,645 pounds] than it actually was.
Investigators described the glitch as "a simple flaw" in an IT system. It was programmed in an unnamed foreign country where the title "Miss" is used for a child and "Ms" for an adult female.
Despite the issue, the thrust used for the departure from Birmingham on 21 July 2020 was only "marginally less" than it should have been, and the "safe operation of the aircraft was not compromised", the AAIB said.
They're still classifying it as a "serious incident" — and also note that because of the same software glitch, two more UK flights also took off on the same day with inaccurate load sheets.
Investigators described the glitch as "a simple flaw" in an IT system. It was programmed in an unnamed foreign country where the title "Miss" is used for a child and "Ms" for an adult female.
Despite the issue, the thrust used for the departure from Birmingham on 21 July 2020 was only "marginally less" than it should have been, and the "safe operation of the aircraft was not compromised", the AAIB said.
They're still classifying it as a "serious incident" — and also note that because of the same software glitch, two more UK flights also took off on the same day with inaccurate load sheets.
Simple Fix (Score:5, Informative)
Adopt the policy of Samoan Airlines. Pay based on passenger+luggage weight.
Curb Your Enthusiasm (Score:2)
https://www.youtube.com/watch?... [youtube.com]
Re:Curb Your Indochimpiasm (Score:1)
It was programmed in an unnamed foreign country where the title "Miss" is used for a child and "Ms" for an adult female.
MsMash wants to have a word with you...
Re:Simple Fix (Score:4, Insightful)
Certainly makes sense, as opposed to most airlines where a 100lb passenger pays the same as a 300lb one, but god forbid your *suitcase* is a pound overweight.
Re: Simple Fix (Score:5, Insightful)
Not so simple upon second glance. Over complicating the price sheet isn't always a smart idea. The additional cost of weighing each passenger. Fixing errors: "You submitted for 150lbs, and you are 200lbs." Expecting people to deal with the the same sardine sized seat even thou they reported 2x or 3x the lowest weight class.
Just the negative PR from embarrassing customers. Consider that even many normal weight folks think themselves over. The airline that does this isn't going to out class the ones that don't.
At the end you still need to adjust for the variances from each person changing slightly in weight from the time they report till they board. Your math isn't getting any simpler, sales are going to tank with higher margins where you want to fill every seat.
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I dunno about now with the COVID restrictions
The COVID restrictions are causing additional challenges for pilots due to planes flying nearly empty. In these circumstances exact passenger weight and distribution change the physics of the planes more than usual.
When an aeroplane flies so light on passengers (and their luggage), passengers are either moved around the cabin or extra ballast is added to the baggage hold to make sure it all balances out.
Aeroplanes function like a giant seesaw. By design, the centre of gravity of the aircraft is near t
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Even pre-COVID this happened occasionally on smaller planes when demand for a particular route was low. My mom and sister were asked to move to the back the last time they flew to see me, because there weren't enough passengers on the plane and they had all booked seats near the front.
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There's something to be said for weighing the passengers. The distribution of the weight matters as much as the total weight. It's less of a problem on larger planes because the law of averages tends to generate a more random weight distribution. But on the smaller commuter planes, there's a higher chance of randomly putting most or all of the heavier people towards the front or back, or on one side. The airline doesn't need to charge different prices for different weights, or tell anyone the weights. But the aggregate weight distribution would be valuable data for the pilots and cargo handlers to have (they can redistribute cargo to offset imbalances in passenger weight). Also, I dunno about now with the COVID restrictions. But you could bribe the curbside baggage handlers to get them to check in an overweight bag without paying the overweight bag fee. It shocked me when I saw it, but my uncle (visiting from another country) casually slipped the guy at LAX a $100 and he tagged 4 overweight bags as being OK and sent them on their merry way on the conveyor belt. I vaguely recall a crash in Africa because this was so rampant that the plane ended up being far over its MTOW.
I worked for a company where the president was a licensed pilot. On occasion he would fly our small engineering department in his Cessna. He had each engineer declare their weight and the President gave specific seats to balance the weight.
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Depends on the number of people. For larger airplanes, like your typical airliner which may have 350+ people, the average weight mechanism is remarkably accurate.
If you're on a smaller plane, smaller than a regional (usually around 10-20 passengers) you have to use actual weights because the average weight may be completely off. Many accidents have happened because of it - like a plane full of soldiers, or a plane of athletes where the average weight of the people will be above the FAA average. In fact, to
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Adopt the policy of Samoan Airlines. Pay based on passenger+luggage weight.
They have to weigh them:
According to WorldData.info, male Samoans have the 7th highest BMI in the world at 30.5. Female Samoans have the second highest, after American Samoa, at 34.1. The Samoan males average height is 1.75m (5ft 7) and the average female Samoan is 1.62cm (5ft 3).
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Their fleet consists of four 19 passenger prop planes [wikipedia.org]. With planes that small, variances in individual passenger weights can make a huge difference. Plus, the passenger cabin needs to be carefully balanced.
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Oops.
Samoa Air [wikipedia.org], the now defunct airline that charged per kilo operated even smaller planes.
BN2 Islander (9 passengers) and Cesna 172 (2 passengers)
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And, of course, they're defunct.
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Would not be legal due to anti discrimination laws. Or they would have to have exceptions for everything - wheelchairs and other medical equipment, medical conditions and treatments that cause weight gain (check the list of side effects on your meds), pregnant passengers, maybe even people required to wear religious dress.
Re:Simple Fix (Score:5, Insightful)
It's a British airline, so it will be British law. At least get the right continent.
Anti-Discrimination Laws May Not Apply Here... (Score:3)
This 2016 article [theconversation.com] notes that "sizeism" is rampant in the UK workplace, but also goes on to note that "At the moment, there is no legal protection from workplace discrimination merely because you are obese, or even just overweight – either from UK or EU law."
So al
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We literally have no idea what the actual weight of the passengers was, we only have two competing ESTIMATES. One estimate treated Miss and Ms as distinct groups with different average weights, another treated tham as equal and applied the same average weight to passengers with either Miss or Ms.
The difference between the two competing evidence is about 2% of the total lift-off weight of the plane - 90,000 pounds for the air frame, 40,000 for the fuel, and whatever these estimates arrive at for baggage and
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A significantly too low estimate is a problem even for airliners because the takeoff performance would be worse than expected - airliners usually don't take off at full thrust in order to prolog engine life - and It might lead to a runway overrun.
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IANAL, but...
I don't believe it would be a violation of the ADA any more than it's a violation of the ADA for the USPS to charge for the mailing of a package of prescription medicine to a disabled person when that medicine is to treat the qualifying disability.
In the generally progressive state I live, it's common for residential leases to specify that a disabled tenant can modify the residence as needed to accommodate their disability (such as grab bars or ramps). However the modifications must be reviewed
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The ADA is irrelevant, this is a British airline operating out of the UK. So UK law applies.
Specifically the law says that airlines must make "reasonable accommodations" for disabled passengers. It doesn't define what a disability is or what reasonable is, that has been left up to courts as is the usual way here.
The courts usually interpret it quite generously, and airlines got ahead of it by allowing things like wheelchairs free of charge anyway.
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So can we sue the post office, UPS, FedEx, etc. because they charged more money to ship a heavier package? End weight discrimination now!
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Nobody is required to wear religious dress. That's a choice you make when you choose to believe nonsense.
No fix required (Score:2)
People see figures like "1200kg" and think OMG! But people don't understand the actual weight of the aircraft and fuel. The aircraft in question was a Boeing 737-800 with a maximum take-off weight of 79,000kg. All 215 passengers put together are only about 20% of the total aircraft weight. And the 1200kg the weight calculation was off in this case only constitutes 1.5% of the actual weight of the aircraft. The amount the thrust was off was so small as to be negligible.
This was classified as a serious i
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This was an incident that had no direct consequences; the takeoff speed was just 1 kt slower than expected. But this kind of errors in the weight calculation can have a more serious impact. On a Qantas flight in 2014, a group of children in the back was not registered as such, causing the plane to be unexpectedly nose-heavy. During takeoff, the pilot to make split-second decisions to get the plane to takeoff safely.
https://www.atsb.gov.au/public... [atsb.gov.au]
https://time.com/3266087/qanta... [time.com]
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Size (volume) matter's, too.
The last time I flew on United, I was put on a seat next to a HUMONGOUS person!
So big that there was not enough room in that 3rd seat after that person and the window passenger were seated.
Needless to say, I vehemently complained and was eventually given a seat with normal-shaped passengers.
The moral is that both that super-obese person AND the airline should make that passenger buy 2 seats,
since, after all, that what was needed! Further, compromised pas
Re:Incorrect pronouns! (Score:5, Insightful)
Referring to someone in a gender-neutral manner when they have not told you they consider themselves as such is still misgendering.
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152lbs (Score:4, Insightful)
An adult that weighs 152lbs? Oh they aren’t talking about Americans. Carry on.
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An adult that weighs 152lbs? Oh they aren’t talking about Americans. Carry on.
an adult *female*, per the fine article.
WTF? (Score:3, Interesting)
Why would they tie a life-critical feature to name parsing?
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And if they are going to go that way, having more than, say, two children per adult should raise an alarm. This is airline software, not aircraft or ATC software. Somebody had a bright idea to speed up check in.
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And why the fuck should airlines ask about someone's marital status, or even sex for that matter? The only thing they should be allowed to ask (require, really) is your weight, because of physics, balancing weight and fuel cost.
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The calculation of weight was off less than 2% - the plane weighs 90,000 pounds, the fuel another 40,000 pounds, and then there is the weight of the passengers and baggage. By it's very nature, the software at best only provides an estimate based on how the passengers self-identify thru their pronouns.
Remember, the 2,645 pound difference is between two estimates, no where is it known what the actual weight of the passengers is - we just have two competing estimates, 2,645 pounds apart.
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Being 2% more massive doesn't just affect fuel. It affects acceleration, which affects take-off, and deceleration when landing. Airlines and pilots do try to leave a safety factor, but using more fuel and then being stuck in the air longer due to bad weather could use up those safety factors very quickly.
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As a (long since retired) private pilot we were taught that the main issue is the relation between the center of mass and the center of lift. As long as the former is ahead of the latter, a stalled aircraft will fall nose down (and recover). If the reverse, it will fall tail first and be impossible to recover.
(The above only applies to straight-ahead flight, different effects occur in a flat spin).
Thus a small difference could, in some circumstances, have a serious effect.
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Why would they tie a life-critical feature to name parsing?
How does parsing a name tell if someone is an adult or child? Or even male or female?
My guess is that there's a box someone needs to check, the passenger themselves or some ticket agent. They have three boxes, Ms, Miss, Mr. That's a guess as I didn't see what the indication was for adult male. A miscommunication on the meaning of these abbreviations can mean the people entering the data would flip the calculation for a 69 kg female for a 35 kg child. It's quite possible for this to go unnoticed for som
Re:WTF? (Score:5, Insightful)
Why would they tie a life-critical feature to name parsing?
Because hiring competent IT professionals costs money.
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yep, airline safety isn't excluded from "made by the lowest bidder".
No it is because it is a legacy system tied to PNR (Score:2)
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Regression testing by whom? The problem with regression testing is it often only finds coding errors, not design errors. This is a fundamental misunderstanding of the statement of requirements, and unless you hire a competent 3rd party not in any way associated with those who made this error in the first place the regression test would pass with flying colours.
Because PNR is an old tech (Score:2)
To paraphrase Steve Ballmer (Score:2)
Funny.. (Score:3)
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Design?
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That may not be practical. Consider the gross weight of a loaded plane, A 747 weights about 400,000 lbs. (737 is lighter) They were off by just over 1,000 lbs. That might just amount to a rounding error on a load sensor of that size. (0.25 %)
If you've got a digital bathroom scale, get on your scale and note the weight. Now get
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Assuming that other languages work the same way as your language is a classic mistake that keeps getting made over and over. It's why things like Unicode are broken and why software often doesn't travel well.
Other classic ones include everywhere having/not having DST, timezones always being a multiple of 1 hour, age being the time since a person was born, people having 2 or 3 names and no more/no fewer, not stating units because everyone uses metric/imperial, text always flows left to right, 1 Unicode glyph
I don't get it (Score:2)
The weight of an unladen Boeing 737 is roughly 90,000 pounds, and this calculation was "only" (my word) 2, 645 pounds off.
Applying 5th grade math to the problem - ignoring the weight of fuel and baggage - that 2,645 pounds represents less than 3% (2.93%), how close do the calculations get? if there isn't a 3% margin for safety, I really think there should be. Add in the 40,000 pounds for a full load of fuel, and the difference is almost 2% (2.03%).
The real question is how was this code specified, coded, tes
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It was not an airplane software, it was airline software.
Surprised there aren't load cells (Score:3)
Not A Glitch (Score:2)
A glitch is something that happens semi-randomly, like a cosmic ray knocking a bit out of whack in memory and corrupting a frame of video. Or powerline noise corrupting a few network packets.
This is a *BUG* Somebody screwed up when programming the thing. Calling bugs "Glitches" is an attempt to make it seem like it was nobody's fault. A process is screwed up somewhere and someone needs to fix it.
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Calling bugs "Glitches" is an attempt to make it seem like it was nobody's fault. A process is screwed up somewhere and someone needs to fix it.
A few days ago there was a story about cosmic rays causing software crashes (some japanese telecom company); again a nice way to explain away difficult to debug/reproduce bugs (usually involving multiple threads and race-conditions). If something is unreproducible, just blame it on the cosmic rays. [It is reproducible, just that it's a rare, 1 in a million kind of event]
"Unnamed country" (Score:3)
It’s possible to suspect that the unnamed country where the position is much more firmly settled doesn’t really exist as described, and the firm national convention linking the choice of “Miss” and “Ms” to adult status is actually established only in the minds of some programmers working there.
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I've been clicking around to find out exactly what country uses "Miss" for (female?) children and Ms. for adult females, and have not found anything. This is worth knowing I think, its an interesting "cultural difference" - if it exists.
Why guess the weight ? (Score:2)
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This is fresh in my mind (Score:2)
I just recently watched a video about the Arrow Air Crash [wikipedia.org] in Canada.
Icing was a major cause, but under-estimating passenger + luggage weight may have been a contributing factor. They used an "average passenger" calculation when carrying US Army soldiers and their gear. The wiki article doesn't mention that, but the video did; not sure about the link for that.
De-icing the plane and planning for a higher take-off weight would most likely have resulted in an incident free flight. Instead, all were lost.
Getting closer to the Event (Score:2)
Where a software error will directly cause the death of hundreds of people
And then the shitstorm will start
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Well isn't Boing's MCAS such an event? I am pretty sure there were other occurences too.
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i'm thinking of an event where like 500 people will die in an event attributed *directly* to a software error.
TuiFly is a member of IATA so..?? (Score:2)
TuiFly is listed as member of IATA. But I'm not sure why Tui was able to let this slip given this should be caught under IATA's Facilitation and Passenger Data "Passenger Name Records (PNR)" standard. https://www.iata.org/en/progra... [iata.org]
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It's a specification error, not a bug (Score:2)
From the comments I gather they estimated weight based on the title of the person (Miss/Ms), instead of using the age of the person. Age is an available information in a passenger database. It would allow a more accurate estimate (adults also become heavier on average as they age).
Why not use that?
Air Midwest Flight 5481 (Score:2)
There were multiple contributory factors to the incident, but one of these was an incorrect weight estimation. From the Wikipedia article:-
"Although the pilots had totaled up the take-off weight of the aircraft before the flight and determined it to be within limits, the plane was actually overloaded and out of balance due to th
Runway Scales (Score:2)
Why don't they have weigh scales on the tarmac?
They really are not that expensive.
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It'd probably be more accurate - and a lot easier to organise - to measure the compression of the differing legs of the suspension to get the total weight (including fuel) after boarding. I suspect that using the existing inflation/ deflation pipework on the tyres, you could also deflect the plane enough with known force
It's not the weight that's an issue (Score:2)
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How does Southwest do it, then, or any airline where you don't have an assigned seat?
A trip back... (Score:2)
... to the Stone Age?