Boeing tells airlines to check pilot seats after shift led plane to plunge
apnews.com
apnews.com
> 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.
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)
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.
https://www.dailymail.co.uk/news/article-3007690/Dozens-inju...
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.
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.