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AirbusMDCFAN
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FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Fri Dec 02, 2016 10:42 pm

From China Aviation Daily: http://www.chinaaviationdaily.com/news/58/58571.html

The Federal Aviation Administration (FAA) is issuing a rule requiring urgent attention by operators of Boeing's 787 Dreamliner to avoid the possibility all three computer modules that manage the jet's flight-control surfaces could briefly stop working while in flight.

Operators must periodically shut and restart the electrical power on the planes, or the power to the three flight control modules. That will avoid the problem until Boeing has a permanent software fix.
In an airworthiness directive to be published Friday, the FAA said it is reacting to indications that "all three flight control modules on the 787 might simultaneously reset if continuously powered on for 22 days."
It said such a simultaneous reset in flight "could result in flight control surfaces not moving in response to flight crew inputs for a short time and consequent temporary loss of controllability."
A person with knowledge of airline practices, speaking on condition of anonymity, said it is "extremely rare" for any operator to leave the jet powered on for longer than a week.

In a statement, Boeing said the new rule mandates actions the jet maker has already recommended to 787 operators during the past two months.

"Boeing recommended that operators cycle power to flight control modules periodically to ensure overlapping resets do not occur," Boeing stated. "A permanent software fix is anticipated in the second quarter of 2017."

The FAA is mandating that the roughly 99 Dreamliners registered in the U.S. act on the directive within a week.

Foreign airlines typically follow the FAA's lead on such directives. To date, 489 Dreamliners have been delivered worldwide.
 
WN732
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Fri Dec 02, 2016 10:45 pm

So basically they just need to do a cold start every 3 weeks?
 
AA737-823
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Fri Dec 02, 2016 11:52 pm

This news came out several years ago.
I realize that the article you linked to is new, as well as the AD I guess, but the revelation that the computers could only store so many dates without a restart was made in, I want to say, 2012-2013.
I don't remember the details, but something to do with memory addressing...

And, for what it's worth, It's unimaginable to me that a carrier is leaving any aircraft fully powered on for three straight weeks. Possible, but highly unlikely.
 
itisi
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:00 am

Would have hoped by now that the 787 was fully operational.... having to restart the computers or having them all shutdown is very troubling.
737-300/400/500 ... are NOT classics :)
 
Okie
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:16 am

AA737-823 wrote:
I realize that the article you linked to is new, as well as the AD I guess, but the revelation that the computers could only store so many dates without a restart was made in, I want to say, 2012-2013.I don't remember the details, but something to do with memory addressing...

You are correct but the time frame was 248 days not the 22 listed in the article with no link to the AD. Having an airframe go 248 days without being powered down or reset would be pretty much unachievable.

This is hard to determine if this is new, with no AD linked or creative news.
I find it interesting if 22 days was an actual time frame that the problem would have appeared long before now.
There are a lot of 787 air frames in use out there.
Obviously anything is possible but I am seriously skeptical at best.


Okie
 
Veetwo
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:18 am

How long is "briefly" in this instance?
Airline employee and Crohn's sufferer.
 
rta
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:23 am

When and how often are jets "powered down"? I assumed this was done almost everyday.
 
jetmatt777
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:28 am

It seems like I remember seeing this a year or two ago?
 
DL777200LR
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:36 am

Airplanes are powered down overnight when maintenance is done, but sometimes may remain powered if departure time is not far away. Maintenance may also power down the plane if required. many widebodies fly overnight thus may not have as much downtime as narrowbodies and an aircraft will usually not be powered down on any quickturn or even if the plane is on the ground for a few hours. so it can happen that an airplane can be left on for a considerable amount of time but it will usually be a widebody aircraft.
Nothing better than the sound of a 77W GE90-115B on engine start.
 
Okie
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 1:13 am

jetmatt777 wrote:
It seems like I remember seeing this a year or two ago?

I thought the same thing about the 248 day AD.

So I checked. The AD is 2016-24-09 dated 12-02-2016. This is apparently a new issue.

Okie
 
CHI87LG
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 1:21 am

So how'd they find that one?
 
Okie
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 1:45 am

CHI87LG wrote:
So how'd they find that one?


good question.
The AD is about as vague as the article "May cause temporary loss of control for a short time"

What exactly is a short time? I suspect what time it takes the FDC to reboot if all three happen to reboot at the same time.
I have no earthly idea.

Okie
 
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vatveng
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 2:07 am

"Have you tried turning it off and back on?" :sarcastic:

Speaking as an I.T. professional, this is the state of software today. Next to nothing can run more than a few days without a reboot.
 
CHI87LG
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 3:04 am

Hey pilots, can y'all leave the planes off when yer done with 'em? Thanks boss.
 
MaksFly
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 3:05 am

It is amazing to think about this...

machine have become so complex that now we resort to essentially control + alt + delete when errors pop up.

I wonder what older pilots think of this.
 
Newbiepilot
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 4:38 am

rta wrote:
When and how often are jets "powered down"? I assumed this was done almost everyday.


A narrowbody would be powered down pretty much every day. Widebodies may go a few days between longer ground times. Airplanes are almost always powered down when not at a gate between flights or when parked for more than 3-4 hours. I would be very surprised if a plane went a week without being powered down.
 
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LAX772LR
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 8:30 am

itisi wrote:
having to restart the computers or having them all shutdown is very troubling.

Why? You do realize that that applies to almost every form of computer-operated equipment, no matter how vital it may be, do you not?
I myself, suspect a more prosaic motive... ~Thranduil
 
shankly
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 9:45 am

Amendment to B787 QR list for unresponsive flight controls:

new item 1 - press ctrl+alt+del
L1011 - P F M
 
trent768
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 10:30 am

How much time is needed to reboot the system? Is it as easy as turning all the power off then turn it back on and your good to go, or it needs to be re-configured?
 
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enzo011
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 10:37 am

Seeing as the FAA is telling airlines to reboot every few weeks, what was the Boeing guidance when designing and selling the aircraft? If Boeing had their system as designed where no reboots would be needed in months, whether this needs to be done all the time in other applications around the world doesn't matter. This would be a procedure that wasn't foreseen by the designers when airlines are operating the aircraft. This is not the end of the world as the procedure to reboot doesn't seem to be prohibitive or time consuming for airlines.

Its a bit like the PW engine start issue for the NEO, the start-up procedure is not that much different than current engines, yet it isn't what airlines were promised.
 
StTim
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 10:42 am

The key issue is that all three systems have the same flaw and thus fail at the same time. If they were changed so that they had different time registers and so failed at independant times it would not be such a problem as they could then be individually rebooted without the potential loss of control.
 
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BobMUC
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 11:38 am

vatveng wrote:
"Have you tried turning it off and back on?" :sarcastic:

Speaking as an I.T. professional, this is the state of software today. Next to nothing can run more than a few days without a reboot.


Have you ever heard about a computer call the Mainframe? ;)
 
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moo
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 11:58 am

BobMUC wrote:
vatveng wrote:
"Have you tried turning it off and back on?" :sarcastic:

Speaking as an I.T. professional, this is the state of software today. Next to nothing can run more than a few days without a reboot.


Have you ever heard about a computer call the Mainframe? ;)


Or a digital telephone exchange. Uptimes in decades, and a reboot results in a mandatory major investigation into the root cause.

This is the level of hardware and software where you can turn off individual CPUs to upgrade or replace them, with the system running just fine while that upgrade happens, just with a constraint on resources available.

A fly by wire system with multiple independent computers should not have to be cold started on a regular basis - a mandatory cold start indicates that the independent computers are not actually independent (if they were, you could reboot each of them individually without an issue), and that is a major failing in this sort of setup.
 
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Rajahdhani
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:33 pm

moo wrote:
...a mandatory cold start indicates that the independent computers are not actually independent (if they were, you could reboot each of them individually without an issue), and that is a major failing in this sort of setup.


Why set it up that way, then? I am not at all doubting your statement, but just wondering what likely determined the use of what is an essentially, less safe, configuration? Costs? Ease of servicing? Space constraints?
 
StTim
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:48 pm

They had a specification that was implemented in the same way in each of the independent systems with no requirement for what happens shoule they be left on for a longer duration.

Sounds a miss in the design and test phase
 
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moo
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 12:56 pm

StTim wrote:
They had a specification that was implemented in the same way in each of the independent systems with no requirement for what happens shoule they be left on for a longer duration.

Sounds a miss in the design and test phase


It doesnt just sound like a miss in the design and test phase, it sounds like a monumental screw up in the design and test phases. At least one of the redundant systems should have been given to a completely separate team, working in different hardware - that would have minimised the chances of a convergent issue affecting all three redundancies. The FAA would have to have signed off on the design and test of this system, which means that the blame goes that high as well - the requirement to reboot all three at the same time indicates there is a major failure in the redundancy here, the exact thing this design is supposed to have at its core.
 
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Stitch
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 2:49 pm

CHI87LG wrote:
So how'd they find that one?


Since there have been no reports of such an issue occurring in-flight, it may have been found in testing either by Boeing or the sub-system manufacturer. And that the FAA says it is a "possibility" and not a "certainty" implies this is not an issue that always happens after 22 days. It may be an extremely rare occurrence, but since it does impact flight-controls, it is a Safety of Flight issue and therefore warrants an AD and a correction.
 
2175301
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 2:55 pm

This does sound like a design flaw. My professional background is in Power Plants; and computerized electronic control systems for Turbine Generators started to be implemented in the early 1990's; with full power plant controls for all equipment in the plant by the late 1990's. Triple redundant systems that could be fully maintained as needed online. Up-time required is at least several years (longest Power Plant run time that I know of is well over 2 years, and 1 year+ is very common). It has been very rare to every have a problem and even need to swap out a circuit board except for the 10-15 year life on the electrolytic capacitors on the circuit boards (and the industry now has vendors that just change the capacitors on old circuit boards about every 9 years).

The systems introduced in the 90's were very compact, so I don't see this as a space/weight issue for aircraft. The most modern versions are just slightly smaller.

There are no secrets on how to build very long run time computerized systems that withstand constant heat, vibration, and even exposure to humidity and occasionally water. So why the current problems? Is this a case where the "younger" generation just felt that they did not need to learn and implement the lessons of yesteryear? I've seen that in other situations.

I do have to admit though, that I do miss the old analog computers that were specifically designed for their exact application. The most modern digital computer cannot replicate the speed of response and accuracy of a properly designed and matched analog computer. Of course, each application had a unique computer - which made them expensive, and added to the spare part inventory that had to be maintained.

Have a great day,
 
Newbiepilot
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 3:10 pm

enzo011 wrote:
Seeing as the FAA is telling airlines to reboot every few weeks, what was the Boeing guidance when designing and selling the aircraft? If Boeing had their system as designed where no reboots would be needed in months, whether this needs to be done all the time in other applications around the world doesn't matter. This would be a procedure that wasn't foreseen by the designers when airlines are operating the aircraft. This is not the end of the world as the procedure to reboot doesn't seem to be prohibitive or time consuming for airlines.

Its a bit like the PW engine start issue for the NEO, the start-up procedure is not that much different than current engines, yet it isn't what airlines were promised.


There is not much guidance in the design phase regarding power cycling. In general it should never be needed and I have never heard of promises or commitments regarding it, but rather complaints when the airplane differs from industry standard practices. If power cycling is needed, then the software simply takes care of it. That will be the eventual fix. While never something that the manufacturers or airlines want Airworthiness directives exist on all airplanes.

This is much different than the engine start issue on the engines. Power cycle problems are an area where the 787 has had some challenges from the start. The airplane is designed to be able to handle power interruptions, but at first the 787 is more susceptible to problems when powering up. The 787 has a number of computers in the common core system. There are over a dozen cards handling most of the computing. When the airplane power drops off and things were not shutdown properly, there initially were problems leading to delays. When switching from ground to APU power, early 787s had trouble with some computers restarting. None of this was in the air. Almost all of those problems have now been fixed. The way I describe it is think of early 787s as a computer from 15 years ago and you wanted to install a printer. 15 years ago you needed software to install the printer and had to carefully follow the proper procedure, otherwise it wouldn't work. Nowadays most of the time you just plug in the printer and it works. Occasionally there are problems, but usually it works. Current 787s are like the new computer. They work much better, but there are still a few kinks. This isn't unique to the 787 either. On the other side of the Atlantic, Airbus is working hard to address all the issues they have with the A350. The same company that designed the 787 power system also designed the A350 (UTAS). The A350 has a flight control airworthiness directive already published too. Mature fleets get about 5 or so per year.

The reason why this is much different than the PW1000 engine start problem is that it is entirely dealt with when the airplane is on the ground and maintenance being performed. There is no operational impact to powering down an airplane once every few weeks. There are a whole lot of maintenance tasks that need to be done. Airlines don't complain about adding engine oil or checking tire pressure since there is no operational impact. However the bowed rotor on the engine requiring the engine to be motored before engine start does have an operational impact since it is done with passengers aboard and after push back.
 
WIederling
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 3:23 pm

AA737-823 wrote:
This news came out several years ago.
I realize that the article you linked to is new, as well as the AD I guess, but the revelation that the computers could only store so many dates without a restart was made in, I want to say, 2012-2013.
I don't remember the details, but something to do with memory addressing...

windows? 64k is enough :-)

And, for what it's worth, It's unimaginable to me that a carrier is leaving any aircraft fully powered on for three straight weeks. Possible, but highly unlikely.


With all the hassle that follows rebooting the systems that is exactly what airlines seem to do.
( if power on the aircraft down nothing seems to be available anymore. not even some cabin lights.)

Comparable effect from being incompatible with ground power units.
Airlines had the plane run on APU all the time.
Murphy is an optimist
 
Newbiepilot
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 3:52 pm

2175301 wrote:
This does sound like a design flaw. My professional background is in Power Plants; and computerized electronic control systems for Turbine Generators started to be implemented in the early 1990's; with full power plant controls for all equipment in the plant by the late 1990's. Triple redundant systems that could be fully maintained as needed online. Up-time required is at least several years (longest Power Plant run time that I know of is well over 2 years, and 1 year+ is very common). It has been very rare to every have a problem and even need to swap out a circuit board except for the 10-15 year life on the electrolytic capacitors on the circuit boards (and the industry now has vendors that just change the capacitors on old circuit boards about every 9 years).

The systems introduced in the 90's were very compact, so I don't see this as a space/weight issue for aircraft. The most modern versions are just slightly smaller.

There are no secrets on how to build very long run time computerized systems that withstand constant heat, vibration, and even exposure to humidity and occasionally water. So why the current problems? Is this a case where the "younger" generation just felt that they did not need to learn and implement the lessons of yesteryear? I've seen that in other situations.

I do have to admit though, that I do miss the old analog computers that were specifically designed for their exact application. The most modern digital computer cannot replicate the speed of response and accuracy of a properly designed and matched analog computer. Of course, each application had a unique computer - which made them expensive, and added to the spare part inventory that had to be maintained.

Have a great day,


I certainly don't think it is the younger generation not implementing lessons learned from the past. The 787 has consolidated many computers into a common core system excluding the flight control computers. It is an evolution on the many different electronic boxes talking to each other from previous generation airplanes. Historically as airplanes age and wiring deteriorates there are a lot of problems with the boxes talking to each other. Ask a 747 mechanic how difficult it is to troubleshoot a no land 3 EICAS message. The 787 has more integrated systems that talk to each other through fiber optics. The problems have shifted from wiring and interface problems to computer and power reset issues. The integrated controllers are only as good as the engineers who wrote the software. I can totally see a case where the designers did not include a memory clearing step as an oversight and it was not captured in testing since an airplane will never typically remained powered up for weeks at a time.
 
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flyingturtle
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 3:56 pm

One time frame specified (those 22 days) is about the maximum number of milliseconds an unsigned 32 bit integer variable can store. 248 days also leads to an integer overflow if you store the number of 1/100 seconds in a variable.


David
Reading accident reports is what calms me down
 
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Aesma
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 4:05 pm

StTim wrote:
The key issue is that all three systems have the same flaw and thus fail at the same time. If they were changed so that they had different time registers and so failed at independant times it would not be such a problem as they could then be individually rebooted without the potential loss of control.


I thought critical flights controls were purposely not all the same to avoid such things, I even had seen somewhere (but maybe it was about the space shuttle ?) that the flight computers were designed by different teams, using different programming languages, to be certain that the same bugs couldn't affect all of them.
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
 
Natflyer
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 4:06 pm

vatveng wrote:
"Have you tried turning it off and back on?" :sarcastic:

Speaking as an I.T. professional, this is the state of software today. Next to nothing can run more than a few days without a reboot.


Works wonders on my 1980's era 757/767s. Power down, count to 5, power back on. Solves a lot of nuisance messages and lights.
 
Newbiepilot
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 4:08 pm

WIederling wrote:
AA737-823 wrote:
This news came out several years ago.
I realize that the article you linked to is new, as well as the AD I guess, but the revelation that the computers could only store so many dates without a restart was made in, I want to say, 2012-2013.
I don't remember the details, but something to do with memory addressing...

windows? 64k is enough :-)

And, for what it's worth, It's unimaginable to me that a carrier is leaving any aircraft fully powered on for three straight weeks. Possible, but highly unlikely.


With all the hassle that follows rebooting the systems that is exactly what airlines seem to do.
( if power on the aircraft down nothing seems to be available anymore. not even some cabin lights.)

Comparable effect from being incompatible with ground power units.
Airlines had the plane run on APU all the time.


What airline is leaving airplanes powered up for weeks at a time? It is possible to continuously operate a plane that long but very unlikely. The only case I could see that happening is in extreme cold climates like Siberia or Canada where cold weather procedures differ from the standard AMM Chapter 10 parking and storage procedures. Airlines do not typically leave airplanes unattended and powered up. Leaving an airplane unattended and powered up for an extended period of time is a procedure not in the maintenance manual. Chapter 10 of the AMM has instructions to power down the airplane. If an airline is not following the AMM, they can expect some problems. Before anyone asks, AMM procedures are not FAA approved documents, so airlines are not required to follow them which is why we sometimes see Airworthiness Directives along with Airworthiness Limitations.
 
JoeCanuck
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 4:12 pm

If it's good enough for my phone, it's good enough for a 787.
What the...?
 
WIederling
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 4:39 pm

flyingturtle wrote:
One time frame specified (those 22 days) is about the maximum number of milliseconds an unsigned 32 bit integer variable can store. 248 days also leads to an integer overflow if you store the number of 1/100 seconds in a variable.
David


And, premeditated, it is easy to program such things in a way that does not bring the system down in flames.
Murphy is an optimist
 
WIederling
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 4:44 pm

Newbiepilot wrote:
Leaving an airplane unattended and powered up for an extended period of time is a procedure not in the maintenance manual. Chapter 10 of the AMM has instructions to power down the airplane.


I am certain Boeing differentiates between
"Powered Down" ( all systems off but enough e-life to have the electronically controlled power switches working.)
and a
"Cold" ( batteries disconnected ) airplane.
Murphy is an optimist
 
MrBretz
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 5:46 pm

I'm on the same page as flyingturtle and the comment about the number of milliseconds in a 32bit integer. Having been a software engineer and manager, I have come across similar instances in my life. But it is all complete speculation on our parts.
 
Newbiepilot
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 8:29 pm

WIederling wrote:
Newbiepilot wrote:
Leaving an airplane unattended and powered up for an extended period of time is a procedure not in the maintenance manual. Chapter 10 of the AMM has instructions to power down the airplane.


I am certain Boeing differentiates between
"Powered Down" ( all systems off but enough e-life to have the electronically controlled power switches working.)
and a
"Cold" ( batteries disconnected ) airplane.


I don't understand what e-life means. On the 787, the powered down configuration has the main battery switch off. It is also recommended that when parked unattended to leave the battery switch off even when the airplane is powered up with an external source.
 
WIederling
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 10:37 pm

Newbiepilot wrote:
I don't understand what e-life means.


You are a Newbie :-?

Quite often with modern electronic systems Off is not Off. There are enough elements still active to
funnel some user request through part of the system to active the remainder ( and majority of systems )

In the most simplistic case think of a real time clock module.
That is never switched off or reset except you actively command it. ( and then have to set time and date like new.)
Though for realtime computing you try to not be dependent on such things in program flow.


And when you switch off the batterie(s) while ground power is active you obviously do not power the plane down.
You just disconnect the batteries ( to avoid problems with over eager chargers?.
Murphy is an optimist
 
Yflyer
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sat Dec 03, 2016 10:56 pm

Natflyer wrote:
vatveng wrote:
"Have you tried turning it off and back on?" :sarcastic:

Speaking as an I.T. professional, this is the state of software today. Next to nothing can run more than a few days without a reboot.


Works wonders on my 1980's era 757/767s. Power down, count to 5, power back on. Solves a lot of nuisance messages and lights.


I was a passenger on an ERJ a few years ago where they did that. After a slight delay at the gate the captain came on the PA and told us something like "We're trying to resolve a technical issue up here, and we're going to try powering down and back on. So don't be alarmed when all the lights go out." Even though I knew it was going to happen, it was a little eerie. As I'm sure you know, it's not like when they turn out the cabin lights during a night flight. Literally all the lights went out. All the reading lights. All the seat belt and no smoking lights. The fans stopped running. It's a little creepy being on a plane before sunrise with literally no lights and no mechanical sounds whatsoever.
 
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vatveng
Posts: 1259
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 4:58 am

moo wrote:
BobMUC wrote:
vatveng wrote:
"Have you tried turning it off and back on?" :sarcastic:

Speaking as an I.T. professional, this is the state of software today. Next to nothing can run more than a few days without a reboot.


Have you ever heard about a computer call the Mainframe? ;)


Or a digital telephone exchange. Uptimes in decades, and a reboot results in a mandatory major investigation into the root cause.

This is the level of hardware and software where you can turn off individual CPUs to upgrade or replace them, with the system running just fine while that upgrade happens, just with a constraint on resources available.

A fly by wire system with multiple independent computers should not have to be cold started on a regular basis - a mandatory cold start indicates that the independent computers are not actually independent (if they were, you could reboot each of them individually without an issue), and that is a major failing in this sort of setup.


Actually, our digital telephone exchange at work requires weekly reboots. The damn thing is flaky as hell. And your observation about independent CPUs is spot-on. Independent computers are rarely that anymore. The systems we use at work are proof of that. You reboot what is supposed to be the "redundant, offline" server and the "online" server throws a fit.

And mainframes, while still in use in places, are a 50-year-old design that's been updated incrementally (much like the 737). Show me anything designed in the last 15 years that isn't full of bugs.
 
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Aesma
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 6:33 am

I think he was talking about hardware used at telcos, not the ones used by companies.

The IPBXs I'm working with only need to be rebooted once a month. It's a recommendation by the manufacturer, otherwise they will decide to reboot when they feel like it, not after a specific number of days. I've seen a couple of them last for 3, even 6 months, because someone screwed up the programming of the monthly reboot. And that's not redundant hardware at all, there is no way to replace anything while it's running (well, except the redundant power supplies, but we haven't bought those), instead the idea is that the phones connect to another IPBX in case of failure.

Now with virtualization, high availability concepts, backup cloud sites, wonderful things are possible, but you need to be strongly committed to these solutions, spend the time and money to make them work, my company's clients would rather pay less and use their mobile phones when something goes down.
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
 
coolian2
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 8:39 am

I assumed even the most well used frame has a cold start in this timeframe.

I suppose Boeing could have left the dud batteries on board and shut them down for long enough to repair fire damage.
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raylee67
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 9:48 am

I thought it's common sense that you should not leave your device (computer, smart phones, etc.) on for more than 22 days.
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AirstairFear
Posts: 52
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Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 10:47 am

flyingturtle wrote:
One time frame specified (those 22 days) is about the maximum number of milliseconds an unsigned 32 bit integer variable can store.

Unsigned will hold 49 days. You likely meant signed. If you have written any software for nuke plants, please go back and review your code. Just kidding. :)
 
rg787
Posts: 118
Joined: Sun Nov 21, 2010 2:28 pm

Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 11:59 am

I don't have anything to add to the discussion, but I would like to thank every poster here for what has been one of the best threads I read in ages. Thank you!
 
uta999
Posts: 938
Joined: Mon Jun 14, 2010 11:10 am

Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 12:35 pm

I run an IT business and my view is that everyone should reboot their computer at least twice a day.
Your computer just got better
 
WIederling
Posts: 9462
Joined: Sun Sep 13, 2015 2:15 pm

Re: FAA Orders Boeing 787 Safety Fix: Reboot Power Once in a While

Sun Dec 04, 2016 1:04 pm

uta999 wrote:
I run an IT business and my view is that everyone should reboot their computer at least twice a day.


do you?
LOL.

The systems I've designed run for years on end. no reboot. uptimes beyond 1000 days.
( why should I reboot a well designed operating system and application software ?)

My desktop system and NAS is always on ( most prominent reason for a powerdown/reboot clean out the fans and eclosure).
Better life expectancy than cycling them every day. ( OK. no Windows anywhere in sight. :-)
Murphy is an optimist

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