Someone at work (in an an aircraft manufacturing company) shared this:
Interestingly, this one’s approach suit my personal politics while, as far as I can tell, is diametrically opposed to his but he still circulated it.
Planned FAA AD for B787,
https://www.theregister.co.uk/2020/04/02/boeing_787_power_cycle_51_days_stale_data/
Airbus is not going to gloat too much because
I was talking to some pilots on a US regional jet about 10 years ago and they said they are required to power down the cockpit after each flight, as the crews change.
I think there are quite a few airliners that need “a hard reset” at regular intervals. It will be interesting to see how they cope with being offline for extended periods of time due to the shutdown we are currently experiencing.
And because its a classic:
Yes A350 bug is even worse but 149h is easy to spot than 51 days, I was wondering how come and aircraft can be left always ON under power for such long?
All this shows is that those who write safety critical software are not supermen, and are probably no better than your nearest PHP hacker who has left SQL injection back doors all over the place
Probably the biggest thing that protects us is the fact that most of the systems are really old, perform very narrow functions (basically do the same thing every day; airline pilots tend to press the same buttons in the same order every time), and a lot of them (like jet engine ECUs) are carefully designed self contained boxes and then don’t get changed for many years.
Defects discovered by crew are reported internally, covered up immediately because the Daily Trash sharks are always circling, while the mfg sh1ts itself and issues a rapid fix under the guise of an innocent sounding “feature update” so the certification agency never finds out 
One might think the reason Airbus are not making political capital out of the B737 saga is because they are upright and decent people, but in fact they are keeping quiet because they know their cupboard has just as many skeletons in it as all the others
Many years ago, 1983, I designed a multizone heating controller which had self-learning optimisation on the advance turn-on. It was all written in Z80 assembler. Many many hundreds were sold and installed (c. £500 each) and no bugs were ever found. Well, all of them will have stopped working in 2012. The reason is that it computed the day of the week from the date (which came out of a clock chip) and the algorithm I used was just a lookup table which took advantage of the fact (?) that a calendar repeats every 29 years, and I never provided for any subsequent 29 year period. I mean, it’s obvious, in 1983 I was 26, and when you are 26 it is unthinkable that you will ever be 55 because nobody who is of any interest to a 26 year old is that old. I left the company (my first business) in 1991, and it went bust in 1993. Go figure, as they say…
I recently spoke to someone who worked on the KFC225 autopilot. The software had one file per function, because the FAA would push for recertification if more than x functions were changed. If you had 100 functions in one file then any edit of that file changed all 100 functions. The result was an almost unreadable source code…
Crashing safety critical software does not surprise me, not even a tiny little bit, having written and seen my fair share of safety critical code. Engineering safety critical stuff is a lot of paper pushing but the engineering part is still strong and obviously important. With engineers being the natural counterpart to paper pushers they will soon leave and what is left is a bunch of paper pushers who can’t code.
And even if you have good people they are only allowed to add functions without changing the surroundings evenif they are broken because testing and recertification is so expensive. I guess in the end it’s probably a symptom of everything which calls itself industry. You start with few talented people and the urge to control them leads to a gigantic mess of processes some 20 or 30 years later which is designed to make a product with a herd of trained monkeys.
Now all the regulators have to do is to encourage hand flying skills in European airlines.
On the news just now. Norwegian (NAS) cancels the purchase of 97 Boeing aircraft. 5 787s and 92 737.MAX. They will also sue Boeing for losses caused by both types.
