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737 'Tailstrike' Caused By Typo On a Tablet (arstechnica.com)
An anonymous reader writes: In August of last year, a Boeing 737 operated by Qantas experienced a tailstrike while taking off — the thrust wasn't great enough for the tail to clear the runway, so it clipped the ground. The investigation into the incident (PDF) has finally been completed, and it found the cause of the accident: the co-pilot accidentally entered the wrong plane weight data into the iPad used to make calculations about the takeoff thrust. "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." This caused the problem: "For a weight of 76,400kg and temperature of 35C, the engine thrust should've been set at 93.1 percent with a takeoff speed of 157 knots; instead, due to the errors, the thrust was set to 88.4 percent and takeoff speed was 146 knots."
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Why can't the source of the data convey the data to the tablet apps automatically? Why involve an error-prone human in the process?
I don't know for sure, but I believe the pilots are supposed to *only* use the certified avionics systems in the aircraft, but they hate the godawful UIs in those things so they use iPads even though they're really, really, really not supposed to.
So somebody entered bad data into the Flight Management Controller.
Happens all the time with Qantas, which has been caught out for having extremely lax protocols.
Search the ATSB database, there have been more than a dozen incidents in the past decade which by pure luck didn't result in mass casualties.
Then read the BS excuses Qantas gives. Such as "the ladder wasn't tall enough to check the engine cowling was locked".
Seems to me 5% should be well within the margin or error. Are they trying to save fuel by cutting it that close?
On a recent flight from SYD to MEL our Qantas pilot ranted on the PA about how evil the ATSB was because they wouldn't let the plane take off, because Qantas engineering accidentally put an incorrect black box into our plane. He said that Qantas maintenance made mistakes like that all the time, and that, since it wasn't a safety issue to fly without a black box, the ATSB were just being pricks.
I will never set foot on a Qantas plane ever agin.
Ok, Einstein. Provide model numbers of the sensors capable of doing what you claim "are clearly easily gathered".
The landing gear use hydraulic and pneumatic systems, and there are already sensors that measure that pressure. The weight of the plane is a simple linear function of the pressure of the fluids in the landing gear.
Because the aircraft can't measure its own weight. This kind of data entry error can occur in any system where a human is required to enter data into computer. Interestingly enough, most commercial planes can't measure how much fuel they're carrying. It's figured out by the guy who is watching the meter when he refuels it, who then passes hat amount to the pilots, who then enter the amount into the computer.
https://en.wikipedia.org/wiki/Gimli_Glider
My step-brother is an onsite supervisor helping to build the new AP1000 reactors at the Vogtle Electric Generating Plant.
He's constantly complaining about the paperwork, how every nut and bolt is documented, and how people are slow to sign-off on paperwork because they're afraid of the buck stopping with them if something breaks.
And yet _his_ projects (the boilers) are way ahead of schedule. Their the only ones ahead of schedule, in fact. Why? Because even though he complains about the red tape and meddling of regulators, he's actually incredibly smart, very hardworking, and he manages to whip the crews he supervises into shape. He doesn't half-ass anything, but he's courageous enough to make the hard decisions, including extra work, that keeps things on time and under budget.
Government (as well as corporate, for similar reasons) projects are expensive not because of paperwork and red tape, but because _real_ people drag their feet. And because they will use paperwork and similar frictions as an excuse for poor performance, rather than treating it as any other challenge one might encounter.
I couldn't even imagine the amount of graft and corner-cutting that would occur without the paperwork holding people's feet to the fire.
Most people are lazy most of the time. Most people don't take pride in their work most of the time. Civilization works because a minority of people prefer getting the job done to whinging, even if they complain almost as much as the next guy.
I am not a pilot so I don't know but I am curious. In all the old war novels I read they just run the throttles to "take off power" and go.
Is there any reason you don't just slam the throttles open on a modern jetliner until you are off the ground? Why do anything other than make sure you are not 'to heavy' to make it before you run out of runway? What not just 'punch it'.
Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html