Airplane takes off with less thrust after adults are assigned child's weight

midian182

Posts: 6,802   +61
Staff member
What just happened? Software errors are a fact of life, but their seriousness can depend on the circumstances. A flight from the UK to Spain took off more than a tonne heavier than expected because female passengers using the title "Miss" had been mistakenly identified as children.

Described as a "serious incident" by the Air Accidents Investigation Branch (AAIB), the error saw 38 passengers on the flight allocated a child's "standard weight" of 35kg (77 pounds) instead of the adult figure of 69kg (152 pounds).

The mistake meant the plane's load sheet, used to calculate inputs during take-off, had a discrepancy of 1,244 kg (2,743 pounds). Thankfully, the pilot said the thrust was only "marginally less" than what was required. "This meant the safe operation of the aircraft was not compromised," wrote the AAIB.

According to the Press Association, the error resulted from an update to Anglo-German airline Tui's reservation system while its planes were grounded because of Covid-19 restrictions. In the unnamed country where the software is programmed, the title "Miss" is used for a child and "Ms" for an adult female.

The system was corrected when the problem was first identified 11 days before the incident, but this did not correct the weight entries for the July 21 flights.

"The health and safety of our customers and crew is always our primary concern. 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," said TUI.

Masthead image: Craig Russell

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Danny101

Posts: 1,656   +708
I made a joke one time to a flight attendant about how many restrooms were there. I wanted to make sure to maintain weight distribution. She was not amused. I've seen then as I see now. Don't make jokes about safety while on the plane. Appears to be a quick way to get you on a No Fly list.
 

wiyosaya

Posts: 5,943   +4,205
Interesting that they would use a title as opposed to something concrete like the age of the passenger to make this calculation. :rolleyes: :facepalm: I wonder how they are making the calculation now??
 

terzaerian

Posts: 923   +1,323
I made a joke one time to a flight attendant about how many restrooms were there. I wanted to make sure to maintain weight distribution. She was not amused. I've seen then as I see now. Don't make jokes about safety while on the plane. Appears to be a quick way to get you on a No Fly list.
It depends on the airline. United? Absolutely. Southwest? They'd be the ones making that joke. :)
 

Emexrulsier

Posts: 619   +92
10 stone 8 is an average adult weight according to the the airline yet the average weight in the UK of a man is 13 stone 1, and woman is 11 stone.

And for comparison in the US the average male is 14 stone 2 and woman are 13 stone.

All of the Europe the average adult weight is 11st.1 above the average again the airline claims.

So from that surely every single flight takes off under thrust, no bloody wonder they say take off and landing is the most dangerous part.
 

Fobus

Posts: 123   +101
Only 69 kg per adult? That doesn't sound like European adults :)

Why? that seems about right for FEMALE adult from presumably UK. American women weigh far more than that. Continental women weight even less. Don't understand why you're surprised about that figure.
 

Markoni35

Posts: 1,078   +442
Why? that seems about right for FEMALE adult from presumably UK. American women weigh far more than that. Continental women weight even less. Don't understand why you're surprised about that figure.

Okay... female, but they aren't all females inside, are they? I mean, if you know the flights where there are all females and no men, please let me know.
 

Fobus

Posts: 123   +101
Okay... female, but they aren't all females inside, are they? I mean, if you know the flights where there are all females and no men, please let me know.
My understanding is only the number for female passengers were subsituted for the one for children because of the language used. Male numbers were right.
 

captaincranky

Posts: 16,804   +5,579
The more I read this topic, the dumber it seems to get.

Load distribution is more critical than total load. Unless the airliner is being used to transport people to a "chronically obese persons convention", IMO, maximum takeoff weight should be assumed, and dealt with accordingly.

In other words, (pilot to tower), "this is Lucifer airlines flight 666 requesting clearance for takeoff. (Tower), "Roger Lucifer 666, you air cleared for takeoff". At that point, the fans are spun up to 100%, and you take your foot off the brakes.

At some point, having some buggy software telling a pilot with perhaps thousands of hours experience in the cockpit, how much power he pilot he or she is "allowed" to use, seems dangerous if not outright stupid, right from the jump.

Quite frankly, passengers should be forced to walk across a scale at the time od boarding, and seats assigned accordingly, thereby maintaining the correct CG, typically at about 25 to 30 % the the airfoil chord. CG too far forward yields poor response to elevator controls, too far back and you in for a wild, rather pitch sensitive seesaw experience, (with a tendency to drop a wing or snap roll. :scream: .).
 
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Markoni35

Posts: 1,078   +442
At some point, having some buggy software telling a pilot with perhaps thousands of hours experience in the cockpit, how much power he pilot he or she is "allowed" to use, seems dangerous if not outright stupid, right from the jump.

That's exactly what happened many times with badly programmed automation. Sometimes just a slight touch to the wheel would cause the autopilot to switch off, signaled just by a small LED switching itself off. Now, among 1000 shiny light bulbs, one switching off, that's so easy to overlook.

Instead of using the voice warning, saying: "Control moved to the pilot because of command column input. Or... computer encountered an error with the external sensor that cannot be interpreted. Please check your pitch. Autopilot switching off."

You can't have 2 captains in command. If automation is in control, it should be reliable. And when it turns itself off, or takes control suddenly without being asked to, it should also state so clearly. The worse thing is adding a virtual crew member who don't respect the basic crew member communication and turns on and off as it wishes. Then it's better without it. At least then you know everything is on you.