
FAA: Reboot 787 power once in a while - pencotts
http://www.seattletimes.com/business/boeing-aerospace/faa-orders-787-safety-fix-reboot-power-once-in-a-while/
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tristanj
Looks like it's a separate issue than the one found last year, where the FAA
directed 787s must be powered off before 248 days of uptime to avoid an
integer overflow bug.

[http://arstechnica.com/information-
technology/2015/05/boeing...](http://arstechnica.com/information-
technology/2015/05/boeing-787-dreamliners-contain-a-potentially-catastrophic-
software-bug/)

~~~
justinsaccount
yeah,

I'd say if they are saying you need to reboot every 22 days, the actual limit
is at least 23.. Why cut things close?

    
    
      22*3600*24 = 1900800 (x1000 for milliseconds)
      23*3600*24 = 1987200
      24*3600*24 = 2073600
      25*3600*24 = 2160000
    

and, as it turns out

    
    
      2^31 / 1000 = 2147483
    

If they are storing a time value as milliseconds in an signed 32 bit int, that
would roll over every ~24:20:30

~~~
qb45
Haha, I think you nailed it. Windows 95 had exactly the same bug, except that
the counter was unsigned so it was taking 48 days to crash. I only hope these
machines aren't flying some modified W95 kernel :)

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zanecodes
>A permanent software fix is anticipated in the second quarter of 2017

Who wants to bet that the permanent fix will be 'automatically reboot the
computers if the plane has been powered on for more than a week and stationary
on the ground for more than N minutes'

~~~
disposablezero
Actually, it's likely given the publicly-traded pressure toward the short-term
cheapest option. Any substatial fix would be subject to passing QA/QC and
validation processes given that safety-critical systems tend to use the
waterfall development model. But, unfortunately, the explosion of subsystem
features and over-engineered solutions leads to a factorial multiverse of
subtle gotchas and inability for humans to prove nonfunctional requirement
properties. Formal verification, feature hesitance ftw.

~~~
WalterBright
> publicly-traded pressure toward the short-term cheapest option

Boeing plays very much the long term game. It took something like several
years in development and 10 years in production for the 747 to make a profit,
for example. It is simply impossible to design and manufacture airliners on
quarterly results.

> cheapest

Boeing is very well aware that the most expensive option for them would be to
acquire a reputation for cheap, unsafe, crummy airliners.

Source: am former 757 flight controls design engineer, and happy Boeing
shareholder for 35 years.

~~~
dingaling
Boeing changed in 1997 when the MDC bean-counters took over. Look at their
line-up for 2020: fourth iteration on the 737 with MoM shaping up to be a
fifth, third iteration on the 747 if it's still alive, third iteration on the
777, 787 range split across the -9/-10 and the -8 which is basically a
completely different aircraft due to the chaotic and rushed development.

"No more Moonshots" is their current self-professed philosophy:

[http://www.seattletimes.com/business/mcnerney-no-more-
lsquom...](http://www.seattletimes.com/business/mcnerney-no-more-
lsquomoonshotsrsquo-as-boeing-develops-new-jets/)

And that's not even addressing their creative methods of program accounting,
or the fact that their suppliers now have to wait 120 days for payment.

[http://www.reuters.com/article/us-boeing-suppliers-
idUSKCN0Z...](http://www.reuters.com/article/us-boeing-suppliers-
idUSKCN0ZN1GG)

None of those sound like the Boeing of old that "bet the farm" on the 747.
Which, anyway, was only meant to be a short-term airframe until supersonic
airliners took over...

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farzadb82
In my day we didn't have no fandangled "reboots". All we did is give our
equipment a little percussive maintenance to get them back into service!

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raverbashing
It's amazing how hardware manufacturers still can't do software.

I know, crap happens, but gosh darn it.

And here's the thing: bureaucracy _doesn 't help_ because it prevents people
from raising issues unless they're big enough.

Every monotonically increasing counter needs to be reviewed for overflow
behaviour and time to overflow

~~~
grogenaut
Show me a piece of software by "Software manufacturers" without a bug and I'll
show you a piece of software with not enough users.

Aka:
[https://www.google.com/search?q=linux+uptime+bug](https://www.google.com/search?q=linux+uptime+bug)

~~~
raverbashing
Good, now search windows uptime bugs, zune leap year bug.

No, there aren't systems without bugs, but some companies make it worse. I
know, I have "worked" for some of them

~~~
grogenaut
I wasn't picking on linux, I was using it as an example of what people
consider stable and pointing long term uptime bugs like the airliner is
suffering from.

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pasbesoin
So, this applies to an entire jetliner?!

"Have you tried turning it off and back on again?"

I don't know whether I'm unsettled, or strangely comforted by the consistency
of the world.

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disposablezero
Add to the list of Embraer EMB-505 Phenom 300, most turboprops.

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vacuumator
A 22 day memory leak...

I hope that's the earliest possible occurence, and not just the typical
average observation.

Wouldn't want to see an edge case, where the system throws an OOM, at 21 days,
due to a process running fast because the CPUs are kept cooler than usual, or
something weird like that.

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exabrial
Another bug: the built in USB charging ports in the back of the seats fried my
galaxy s7 data connection! After my flight, the USB functionality and the
quick charge function of my phone completely stopped working!

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doggydogs94
For computers big and small, the goto solution is Reboot.

~~~
gomijacogeo
Until all the MRAM and other persistent technologies hit. Then get ready for a
generation of college graduates telling us old-timers that 'reboots' are
unnecessary and loading immediately the previous system state is the new mason
jar of systems goodness.

