I was running late for the last flight home on a Friday a handful of years back. Skipped a late lunch and got to the gate just in time to find out the plane is late too. We boarded the plane but after an hour they unloaded us. Turns out they couldn't open the "fuel flap" and were going to try a "cold reboot" to fix it. If that didn't work they'd fly in another plane from some other city. I was supposed to be home in time for dinner and to tuck my kids in, but I rolled in at 2am. The "reboot" actually worked, it just takes a bit of time. You can't be on the plane when it "reboots" because they turn off the AC and it heats up a lot.
I've wondered about that a lot over the years. I generally don't fly on Fridays after noon anymore, not for work, nobody wants to actually be there at that time. I'm really curious about the process. What kind of system integration has a fuel door system that is so tightly integrated to the rest of the computers that it requries a complete reboot to reset? Was that some mechanic's last idea? Was it from Boeing or Airbus? Is it in the playbook? Is there a more elaborate debug process and they short cutted by rebooting? Is there a fault log that will help fix the actual issue or is it just gone? I dutifully got on the plane that time but I've sort of concluded that in the future, I'd make some calls and just pay too much to spend the night at the airport hotel and fly the next day.
"So here's the thing Mr. F-35 pilot.... the plane needs ctrl-alt-delete but it will drop like a rock from the sky while the computers are booting up... so you need to hold down the power button for 5 seconds, like a solid 5 Mississippis and then all the lights will shut off. Wait another 5 seconds and the press the power button again and it shoooould boot back up... You'll hear a nice pleasant chime and see our logo on the flight control monitor and then after about a minute when the POST completes and it boots up, you should be back in action.." Everyone involved with all of that is just cut from different cloth.
The 787 had three such bugs, in 2015 it was found out if the plane wasn't restarted once every 248 days (2^31 100ths of a second), the AC generation system would shut off, even mid-flight[0].
In 2016 it was found that if the plane wasn't restarted once every 22 days the 3 flight computers could reboot simultaneously, also in mid-flight[1].
In 2020 it was found that if it wasn't restarted at least every 51 days that the stale data monitoring system, and the stall and overspeed horns all stop operating[2].
Some A350s also had an uptime-dependent fault found in 2019[3].
> What kind of system integration has a fuel door system that is so tightly integrated to the rest of the computers that it requires a complete reboot to reset?
I've wondered about that a lot over the years. I generally don't fly on Fridays after noon anymore, not for work, nobody wants to actually be there at that time. I'm really curious about the process. What kind of system integration has a fuel door system that is so tightly integrated to the rest of the computers that it requries a complete reboot to reset? Was that some mechanic's last idea? Was it from Boeing or Airbus? Is it in the playbook? Is there a more elaborate debug process and they short cutted by rebooting? Is there a fault log that will help fix the actual issue or is it just gone? I dutifully got on the plane that time but I've sort of concluded that in the future, I'd make some calls and just pay too much to spend the night at the airport hotel and fly the next day.
"So here's the thing Mr. F-35 pilot.... the plane needs ctrl-alt-delete but it will drop like a rock from the sky while the computers are booting up... so you need to hold down the power button for 5 seconds, like a solid 5 Mississippis and then all the lights will shut off. Wait another 5 seconds and the press the power button again and it shoooould boot back up... You'll hear a nice pleasant chime and see our logo on the flight control monitor and then after about a minute when the POST completes and it boots up, you should be back in action.." Everyone involved with all of that is just cut from different cloth.