Oh Oh, fat fingered Co Pilot

_Tombstone_

Story about a Captain and a Co Pilot that can't add and can't tell the difference between 35°C and 51°C.

On August 1 last year, a Boeing 737-838 (VH-VZR) operated by Qantas performed a "tailstrike" while taking off from Sydney airport. Today, the Australian Transport Safety Bureau (ATSB) has concluded that the strike was caused by the co-pilot fat-fingering the plane's takeoff weight: instead of typing the plane's actual weight of 76,400kg into the iPad, he accidentally typed 66,400kg. As a result, the plane didn't have quite enough thrust to clear the runway without clipping the ground with its tail.

Before you get too panicky, don't worry: this was still very much a human error. The iPad wasn't directly hooked up to the plane; the tailstrike wasn't caused by some software glitch in iOS.

According to the ATSB investigation (PDF), two mishaps occurred "independently and inadvertently." First, when working out the plane's takeoff weight on a notepad, the captain forgot to carry the "1," resulting in an erroneous weight of 66,400kg rather than 76,400kg. Second, the co-pilot made a "transposition error" when carrying out the same calculation on the Qantas on-board performance tool (OPT)—an iPad app for calculating takeoff speed, amongst other things. "Transposition error" is an investigatory euphemism for "he accidentally hit 6 on the keyboard rather than 7."

The co-pilot also entered the wrong temperature into the OPT—51°C rather than 35°C—but the investigation doesn't discuss why that happened, instead focusing on the takeoff weight issue.

http://arstechnica.com/gadgets/2015/11/qantas-737-tailstrike-was-caused-by-ipad-data-entry-fail/

LiamaDelta

Wasn't really a 'fat finger' incident then was it? He added them up incorrectly and transposed the incorrect result to the OPT

basill

As far as I am aware just about every airline that has implemented an EFB solution no matter what checks and balances are in place have had a tail strike or close call. It's just a matter of time.

billy few mates

basill wrote: »

As far as I am aware just about every airline that has implemented an EFB solution no matter what checks and balances are in place have had a tail strike or close call. It's just a matter of time.

Like this one...

https://www.flightglobal.com/news/articles/emirates-tail-strike-crew-missed-chances-to-catch-weight-366472/

https://en.m.wikipedia.org/wiki/Emirates_Flight_407

bkehoe

_Tombstone_ wrote: »

Story about a Captain and a Co Pilot that can't add and can't tell the difference between 35°C and 51°C.



http://arstechnica.com/gadgets/2015/11/qantas-737-tailstrike-was-caused-by-ipad-data-entry-fail/

Both OPTs would have provided an assumed temperature of 51 degrees; they never knew that 35 degrees was the correct assumed temperature to use as they had the incorrect weight in both iPads so that is why the investigation didn't focus on it and why saying they couldn't tell the difference is unfair.

The only question could have been raised from gut feeling/experience i.e. "Gosh, that seems like a high assumption for this runway and a full flight"!

RobAMerc

can someone please explain why aircraft cannot calculate their own actual weight and just have the flight crew verify if as accurate ?

Second Toughest in_the Freshers

A transposition error would have been entering 53 instead of 35, or getting the digits of the order the round way wrong

billy few mates

RobAMerc wrote: »

can someone please explain why aircraft cannot calculate their own actual weight and just have the flight crew verify if as accurate ?

They don't have the ability to weigh themselves, you have to tell the FMC Or FMGC the weight of the pax, bags, cargo and fuel etc which is different on every sector....

Manic Moran

billy few mates wrote: »

They don't have the ability to weigh themselves, you have to tell the FMC Or FMGC the weight of the pax, bags, cargo and fuel etc which is different on every sector....

It would not seem beyond possibility for the three oleos on a typical airplane to have sensors showing just how much they are compressed, and thus estimate weight with a pretty reasonable level of accuracy, no?

billy few mates

Not really, oleo compression is not necessarily an indication of the weight of an A/C, it could also be an indication of poor servicing or a leak on the leg.
I seem to remember one of the big manufacturers toying with the idea of such a system but I don't know if anything ever came of it. It's really not that difficult to do, it only takes seconds to enter the figures and then they're supposed to be verified by both crew members before entering. Most operators also use flight planning software on laptops or iPads which refuse to accept obvious gross errors like these and you can't proceed with the final figures unless everything adds up....

eatmyshorts

Manic Moran wrote: »

It would not seem beyond possibility for the three oleos on a typical airplane to have sensors showing just how much they are compressed, and thus estimate weight with a pretty reasonable level of accuracy, no?

Boeing tried that oleo method on old 747 Classics way back in the 70's.
Sounds great in principle, but in reality their use was fraught with problems and errors that eventually most operators either disregarded them or deactivated the systems.

billy few mates

Apart from the obvious issues with trying to install (and maintain) an accurate and sensitive piece of equipment into a part of the A/C designed to absorb the initial shock of the impact of a large object being driven into the ground it's just not worth the effort of having such a system to do what can easily be done in seconds. There are also too many variables to be considered in programming such a system to take account for the different operating requirements and regulations.
It's far simpler to do it manually using the parameters set by EU Ops part 1 Subpart J

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2008:254:0001:0238:EN:PDF