> The Wall Street Journal reported late Thursday that a flight attendant serving a meal in the cockpit hit a switch on the back of a seat that pushed the pilot into controls on the 787, pushing down the nose of the plane. The newspaper cited anonymous U.S. industry officials who were briefed on preliminary findings from the investigation.
This sounds a lot like a design issue. If the button is on the back of the seat it is probably not meant to be operated with a pilot in the seat, yet it could be (accidentally) operated with a pilot in the seat.
We don't know the details, but any switch pointing to areas people move in should have a switch guard on especially when pressing it can lead to 50 hurt people. But in this case I'd propose the switch should either be at a totally different position or not activate if there is someone in the seat.
Sensors detecting someone in the seat is still more complexity prone to unexpected failures. Most seem like they would be harmless, but then there's one that floods a sensor bus, etc.
I would want to understand why a pilots resistance to the motion was not enough, how could it be made less capable at winning that battle and fall into its normal back off?
- such an airplane already should have sensors to judge whether someone is in the seat or not
- a false-negative preventing the shift of a seat mid-air isn't that critical of a failure (compared to a false-positive, where the seat shifts despite someone being in it)
I think such an airplane has this sensor to the extent that it is a modern misdesign roped in by the ease of adding unnecessary parts.
Who has tested the plane with no detectable pilots in real flight, how often will these sensors be in the percentage of unnecessary parts in defect.
Now that people are thinking this way did they forget that a good seat adjuster can't be overbuilt to destroy or kill whatever is in front of it when it is allowed to operate?
Self recovering fuses are cheaper than ever and are all that's needed if no one has upgraded parts based on higher is better instead of designing to use.
Sure, I agree with you, but you might want to consider that an indication if a seat is filled might be useful for other things as well — in the end there has to be a total calculation that factors the reliability of any given part (and rhe humans using it) in.
There were a bunch of lawsuits against Cessna for worn out seat rails. You adjust the seat forward and back and a spring loaded pin goes into one of the holes in a track to keep it from moving. The holes would get worn out until one day on takeoff you’d be holding the yoke and as you rotated for takeoff the seat would release and slide back. You’d pull the yoke with you so you’d almost instantly be deeply stalled and pancake right back onto the runway.
They should have told informed every customer about this "feature". It seems Boeing waits for something bad to happen to then reveal the feature that caused the accident. Same thing with the MCAS.
I'm not sure how this one is an airline process issue. Boeing recommended checking pilot seats, pointing to instructions on disassembling the seat motors.
Towards the end of the article it mentions that motor switches should be securely covered and not used during flight. Both sound like potential design flaws - if the motors should never be used during flight they should have covers that can't be left open and/or the motors should be disabled while in the air.
> if the motors should never be used during flight
The article is wrong: there are absolutely reasons to adjust seats during flight. They're just relatively infrequent. A secure switch cover is an appropriate mitigation for the risks of inadvertent seat movement.
There's the switches used to adjust the seat when you're in it, and then there's these switches used to adjust the seat when you're not. E.g. to get into the seat during a crew change in flight, or FAs are trained to use these switches to render aid to an incapacitated crew member.
There was an issue where the switches could be out of position and the cover would be ineffective (this is part of that service bulletin).
It's unclear whether the FA deliberately hit the switch (there are rumors that FAs used the switch to serve food to pilots), whether the cover was left open, or whether the cover was ineffective.
Thanks for the clarification here! I don't know enough about the flight operations here so I just kept it with the article's explanation and a big if this is accurate.
> The Wall Street Journal reported late Thursday that a flight attendant serving a meal in the cockpit hit a switch on the back of a seat that pushed the pilot into controls on the 787, pushing down the nose of the plane. The newspaper cited anonymous U.S. industry officials who were briefed on preliminary findings from the investigation.
This sounds a lot like a design issue. If the button is on the back of the seat it is probably not meant to be operated with a pilot in the seat, yet it could be (accidentally) operated with a pilot in the seat.
We don't know the details, but any switch pointing to areas people move in should have a switch guard on especially when pressing it can lead to 50 hurt people. But in this case I'd propose the switch should either be at a totally different position or not activate if there is someone in the seat.