Sasha
Posts: 856
Joined: Tue May 18, 1999 3:26 am

"Rebooting" The Aircraft.

Wed Oct 14, 2009 8:42 am

Hello everyone,
Recently while reading a traveller's blog stumbled upon his mention of a "systems reboot".

Apparently as they were getting ready for pushback, something wasn't just working out (perhaps at some pre-departure checklist stage?) and the Captain announced over the comms that he was gonna need to "reboot the plane". The passenger writes that it lasted for like 5 mins, during which complete power down was done - all lights blacked out. After that the power was back on... eventually the crew admitted couldn't carry on with the flight - so the airline deplaned the pax and put on another plane few hours later.

Could someone please care to comment what that reboot procedure rectifies and if there even is really a procedure like that?

The flight in question was SVO-VVO operated by SU, so I assume we're talking about a Boeing 767-300 here.
An2/24/28,Yak42,Tu154/134,IL18/62/96,B737/757/767,A310/320/319,F100,BAe146,EMB-145,CRJ,A340-600,B747-400,A-330-300,A-340
 
challengerdan
Posts: 145
Joined: Sat Sep 27, 2003 3:17 pm

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 9:19 am

It is fairly common for modern aircrafts to require a "reboot".
For me, the model I did the most reboots on is the Ejet.
It is pretty common also on the CR7/9, a little less with the CR2.
But all in all, you need to remember airplanes now use many computers, sometimes airplanes are powered for really long periods and software starts "acting" faults get recorded, and so on.
Power down and power up also has many system doing POBIT (power-on built-in test) so it helps sometimes in troubleshooting.

When I work on DH8, or when I used to work on Lear 35s, you don't need reboots, but then there is not much computing power involved either.

I don't work on the Big Irons, but I can assume it is pretty much comparable.
if your flight goes MX in YUL, I might be called to fix it!
 
User avatar
Starlionblue
Posts: 17058
Joined: Fri Feb 27, 2004 9:54 pm

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 9:31 am

Sounds exactly like any other computers.

One should not think that reboots are a sign of failure or major flaws. Sure, in a perfect world computers would keep working perfectly for indefinite periods. But in reality very few computers can do that and they are very expensive. Mainframes would be one example. The reason reboots are good is that they are an easy way to start from a known state, thus solving a lot of problems that creep in over time. Why bother troubleshooting when you can be at a known error free state in a few minutes?
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
boeing767mech
Posts: 804
Joined: Fri Dec 15, 2000 5:03 pm

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 1:48 pm



Quoting SashA (Thread starter):
Could someone please care to comment what that reboot procedure rectifies and if there even is really a procedure like that?

I had to reboot an MD-80 the other day, not because of a computer problem, but due to the fact we had a external power relay that would not relax. This was all cause because of a bad Bus Control Unit. which was changed during the black out. SO the paxs spent 2 minutes in the dark while I changed the unit.

It wasn't really a reboot, but a power down. But it is along the same thing as a reboot.

David
Never under-estimate the predictably of stupidty
 
Dalmd88
Posts: 2391
Joined: Fri Jul 28, 2000 3:19 am

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 3:47 pm

Sometimes it also has to do with the 'quality' of the power. Some jet ways power units will provide erratic power. Not bad enough to kick off line but bad enough that the plane might not let some system turn on. Sometimes just switching to the airplanes own APU power solves the problem, others it is essentally a lock out. The downpower reboot is a good quick thing to try before you start changing expensive parts.
 
dispatchguy
Posts: 605
Joined: Sun Jan 29, 2006 6:08 am

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 5:15 pm

When I dispatched Airbus equipment, reboots were very common as the computers are built with very minor tolerances, and depending on the quality of the ground power, a lot of times we would get an ECAM message that rebooting the aircraft would usually fix.

Also, when the overnite weather was brutal cold (I'm thinking Calgary or Edmonton, cant recall which right now), the airplanes were brutally finicky as they were warming up for the morning departure.

DS
Nobody screws you better than an airline job!
 
aogdesk
Posts: 748
Joined: Wed Jun 09, 2004 2:26 am

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 5:35 pm

Definitely one of the quickest and easiest things to do for certain issues. You have to make sure though that you a) remove all sources of power and b) wait long enough before supplying power again, the latter allows all of the relays to relax which might not happen if you quickly switch off and on again.
 
User avatar
Faro
Posts: 1491
Joined: Sun Aug 12, 2007 1:08 am

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 5:47 pm

In a previous thread FMS Operating Systems (by Faro Jul 24 2009 in Tech Ops), FMS and general aircraft operating systems were discussed. As was made clear in the thread, aircraft computer systems and related OS's are designed to be super-duper reliable. I am therefore surprised that rebooting should be a common occurence.

I imagine that all these reboots concern secondary or even tertiary, non-critical systems; I find it hard, for example, to conceive of a flight control computer needing rebooting. After all, if it can happen on the ground, then it can happen in the air...

Faro
The chalice not my son
 
fr8mech
Posts: 6606
Joined: Mon Sep 26, 2005 9:00 am

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 6:08 pm



Quoting Faro (Reply 7):
I imagine that all these reboots concern secondary or even tertiary, non-critical systems; I find it hard, for example, to conceive of a flight control computer needing rebooting. After all, if it can happen on the ground, then it can happen in the air...

Something you need to understand is that, while on the ground, the aircraft may be drawing power from a ground unit. These units may not be providing the cleanest power. It clean enough for the aircraft to accept the power, but some systems may not like it very much.

We routinely pull circuit breakers on blackboxes in order to power them down and bring them back up after a reported issues. It is a normal process. It's when the proces is repeated on the same aircraft, for the same system, that we get concerned and start looking for something that is broken.
When seconds count...the police are minutes away.
 
AAR90
Posts: 3140
Joined: Fri Jan 21, 2000 11:51 am

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 7:32 pm



Quoting Faro (Reply 7):
I am therefore surprised that rebooting should be a common occurence.

"Common" for those of us who fly or maintain these planes on a daily basis. Not very common in the overall scheme of things. The MD90's reputation for requiring "re-boot" is legendary. OTOH, in over a year of 4-7 flights per day my personal experience was less than 3% encounter rate --extremely high in aviation, but not "common" by any means.

Quoting Fr8Mech (Reply 8):
Something you need to understand is that, while on the ground, the aircraft may be drawing power from a ground unit. These units may not be providing the cleanest power. It clean enough for the aircraft to accept the power, but some systems may not like it very much.

The MD90 general rule of thumb --which we pilots tried to strictly enforce-- is that once on acft power do NOT allow ground power cord to come anywhere NEAR the acft ! ! ! Once we got that rule more generally applied, the need to "re-boot" almost disappeared.
*NO CARRIER* -- A Naval Aviator's worst nightmare!
 
DashTrash
Posts: 1266
Joined: Mon Aug 21, 2006 8:44 am

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 10:40 pm



Quoting Challengerdan (Reply 1):
When I work on DH8, or when I used to work on Lear 35s, you don't need reboots, but then there is not much computing power involved either.

The Dash 8 is where I learned what "re-booting" an airplane meant. Power down / power up is pretty common on most airplanes.
 
User avatar
Starlionblue
Posts: 17058
Joined: Fri Feb 27, 2004 9:54 pm

RE: "Rebooting" The Aircraft.

Wed Oct 14, 2009 11:31 pm



Quoting Faro (Reply 7):
I am therefore surprised that rebooting should be a common occurence.

As I said it is not an indication of failure or necessarily major fault.

Quoting Faro (Reply 7):
I imagine that all these reboots concern secondary or even tertiary, non-critical systems; I find it hard, for example, to conceive of a flight control computer needing rebooting. After all, if it can happen on the ground, then it can happen in the air...

As I understand it critical systems can also be rebooted. It is an easier troubleshooting step. If you are in the air I guess you live with the error and work around it. But on the ground it is easier to just reboot.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 12:24 am



Quoting Faro (Reply 7):
As was made clear in the thread, aircraft computer systems and related OS's are designed to be super-duper reliable. I am therefore surprised that rebooting should be a common occurence.

There's a very wide gulf between unsafe (where the reliability lies) and finicky. A computer locking up to the extent that it can't function safely is very very rare. A computer doing something wierd that results in a non-critical status message or something like that is much more common. You could technically fly with it, but it's may be simpler and preferable to reboot and see if it clears before you do anything further.

Quoting Faro (Reply 7):
I imagine that all these reboots concern secondary or even tertiary, non-critical systems; I find it hard, for example, to conceive of a flight control computer needing rebooting. After all, if it can happen on the ground, then it can happen in the air...

Yes, but the requirements to dispatch are much stricter than what you can fly with. If a computer throws a hissy fit and a status or maintenance fault during flight, it's not a big deal...that's why the fuctions (not necessarily individual components) are near bullet-proof and redundant. You just keep going and maintenance fixes it when you arrive (possibly by rebooting). If you're sitting at the gate, pre-dispatch, and you've got a latched fault from the last flight or something like that, you may need to deal with it before you can leave.

Most of the time, in my experience, it's not the computer itself that's the problem...it's either sync between multiple computers or a bad input (finicky sensor, intermittent contact, loose wire, etc.) that caused the computer to get into a state it (by design) doesn't want to get out of without maintenance doing something.

Tom.
 
User avatar
Faro
Posts: 1491
Joined: Sun Aug 12, 2007 1:08 am

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 8:28 am



Quoting Starlionblue (Reply 11):
Quoting Faro (Reply 7):
I imagine that all these reboots concern secondary or even tertiary, non-critical systems; I find it hard, for example, to conceive of a flight control computer needing rebooting. After all, if it can happen on the ground, then it can happen in the air...

As I understand it critical systems can also be rebooted. It is an easier troubleshooting step. If you are in the air I guess you live with the error and work around it. But on the ground it is easier to just reboot.

If you refer to redundancy, then I agree, yes. If flight control computer A needs rebooting but you can manually select flight control computer B in the meantime, then it makes sense.

The hitch is having a need to reboot that simultaneously results in an incident (flight path excursion, engine irregularity, etc).

Faro
The chalice not my son
 
Sasha
Posts: 856
Joined: Tue May 18, 1999 3:26 am

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 9:00 am

Thank you everyone for valuable input. So now I can rest assured that reboot of a plane isn't an indication of something drastic.

I work in IT field and naturally was concerned to find out reboots existed in plane operations, esp with pax loaded and during pre-taxi checks.  Smile
An2/24/28,Yak42,Tu154/134,IL18/62/96,B737/757/767,A310/320/319,F100,BAe146,EMB-145,CRJ,A340-600,B747-400,A-330-300,A-340
 
User avatar
Starlionblue
Posts: 17058
Joined: Fri Feb 27, 2004 9:54 pm

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 9:44 am



Quoting Faro (Reply 13):
The hitch is having a need to reboot that simultaneously results in an incident (flight path excursion, engine irregularity, etc).

Well, sure, but as Tdscanuck explained that sort of thing doesn't really happen. That is, a fault in the computers will not cause that kind of thing. Note the "by design" in the below. That's the key. The computer might "gets stuck" by design if there is a sensor glitch or whatever. That way it is in a known faulty state instead of in an unknown one.


Quoting Tdscanuck (Reply 12):
Most of the time, in my experience, it's not the computer itself that's the problem...it's either sync between multiple computers or a bad input (finicky sensor, intermittent contact, loose wire, etc.) that caused the computer to get into a state it (by design) doesn't want to get out of without maintenance doing something.

"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
User avatar
autothrust
Posts: 1455
Joined: Sun Jun 11, 2006 8:54 pm

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 10:33 am

Just to add a interesting fact about fail-safe to this topic:

When Airbus designed their flight envelope system they wanted it to make it as safe as possible.

Thats why in a A330 five flightcomputers are installed. Three primary and two secundary computers. Each computer software was written in diffrent country's from diffrent company's in diffrent programming languages to achieve highest protection of a total system loss.

Now the question is the communication between the computers aswell as fail-safe?

http://wissen.spiegel.de/wissen/doku...envelope&quellen=&qcrubrik=artikel
“Faliure is not an option.”
 
LimaFoxTango
Posts: 795
Joined: Wed Jun 16, 2004 11:33 pm

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 1:03 pm



Quoting DashTrash (Reply 10):
The Dash 8 is where I learned what "re-booting" an airplane meant. Power down / power up is pretty common on most airplanes.

Ditto. I swear a simple power reset fixes anything in that airplane.
You are said to be a good pilot when your take-off's equal your landings.
 
DeltaGuy
Posts: 3965
Joined: Wed Sep 12, 2001 5:25 am

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 3:00 pm

Modern day aircraft are flying computers- sometimes you have to shut down to dark to clear faults or something turned on the wrong sequence in order to correct it.

In the G450/550, when you bring the batteries on, the Display Controllers will say "Powerup Test in Progress"...you don't touch anything for about 60 seconds as it's running through it's powerup BITE tests, etc. All the avionics racks are full of computer/video cards, and are running through their tests during the powerup.

Like DALMD88 said, sometimes you can get some 'dirty' power, and a Bus Power Control Unit (BPCU) won't allow that power on the aircraft. Sometimes some funky stuff can happen with bad ground power.

DeltaGuy
"The cockpit, what is it?" "It's the little room in the front of the plane where the pilot sits, but that's not importan
 
B727LVR
Posts: 233
Joined: Fri Jul 11, 2008 7:54 am

RE: "Rebooting" The Aircraft.

Thu Oct 15, 2009 9:44 pm

I can't even begin to count how many times disconnecting a cannon plug and then re seating it has actually fixed a problem. Kinda crazy at how the short simple things fix so many problems.
I'm like a kid in a candy store when it comes to planes!
 
Woodreau
Posts: 1182
Joined: Mon Sep 24, 2001 6:44 am

RE: "Rebooting" The Aircraft.

Fri Oct 16, 2009 12:02 pm



Quoting B727LVR (Reply 19):
I can't even begin to count how many times disconnecting a cannon plug and then re seating it has actually fixed a problem. Kinda crazy at how the short simple things fix so many problems.

second the cannon plug thing. - we'd get a balky missile onto the launcher rail - send the chief out to the missile launcher - chief kicks/bangs on the cannon plug connector connecting the missile to the launcher (where it uploads the fire control data from the ship's computers to the missile) - computer finally shows the missile good to go - chief runs back behind the safety of cover - missile launches normally.



re: rebooting the airplane - it's definitely the easiest way to clear a message that shows up on your EICAS that isn't supposed to be there. One of the first thing maintenance will ask you if you call them about an EICAS message that won't allow you to dispatch is - did you power down the aircraft and reboot?
Bonus animus sit, ab experientia. Quod salvatum fuerit de malis usu venit judicium.
 
mirrodie
Posts: 6789
Joined: Wed Apr 19, 2000 3:33 am

RE: "Rebooting" The Aircraft.

Fri Oct 16, 2009 3:59 pm



Quoting Dispatchguy (Reply 5):
When I dispatched Airbus equipment, reboots were very common as the computers are built with very minor tolerances, and depending on the quality of the ground power, a lot of times we would get an ECAM message that rebooting the aircraft would usually fix.

I'll admit I am out of my league here, but last summer, on an B6 A320 at FLL, we were taking off down the runway when suddenly the pilot aborted the takeoff.

We had reached 85 knots (per the pilots announcement) before the brakes were applied.

Back at the gate, the pilots announced some sensor had gone off, they called in some techs to review and we took off about 2 hours later.

But I distinctly recall right before leaving the gate again that the pilot announced, "We just have to reboot the computer and we'll be on our way."


Now, here is my question, part of my memory thought he said, "We have to reboot Windows" again, but I doubt it. Is windows run on an A320?
Forum moderator 2001-2010; He's a pedantic, pontificating, pretentious bastard, a belligerent old fart, a worthless st
 
David L
Posts: 8547
Joined: Tue May 18, 1999 2:26 am

RE: "Rebooting" The Aircraft.

Fri Oct 16, 2009 6:24 pm



Quoting Mirrodie (Reply 21):
Is windows run on an A320?

Um... apologies in advance for any sense of humour bypass I may be suffering but... no, absolutely not! Windows is fine for what it's supposed to do (in spite of what some might say) but it was never designed for flight-critical applications - it's not even close. I don't know what individual airlines use for their IFE but... no, Airbus itself does not use Windows on its aircraft!  Smile
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: "Rebooting" The Aircraft.

Fri Oct 16, 2009 10:53 pm



Quoting David L (Reply 22):
I don't know what individual airlines use for their IFE but... no, Airbus itself does not use Windows on its aircraft!

Some IFE runs on windows. Also some EFB's. So it's possible that Airbus has copies of Windows flying on their aircraft, but not for any flight-critical functions.

Tom.
 
pilotpip
Posts: 2820
Joined: Fri Sep 19, 2003 3:26 pm

RE: "Rebooting" The Aircraft.

Fri Oct 16, 2009 11:48 pm

E-170s can be temperamental. We'll get erroneous messages from time to time. Usually just results in powering everything down, letting it sit for a couple minutes and starting back up. Our 175s, despite being less than 10 months old seem to have more issues than the older 170s. I would venture to guess it has something to do with software updates.

The biggest contributor is ground power. If the airplane doesn't like what it's getting she'll take the GPU off line to protect the electronics. I had that happen yesterday at the MAT at LGA. There was a nasty power surge that knocked all the jetways down and along with that came the GPUs. We turned off the battery masters, let it sit for a minute and then got everything going again in 5 frantic minutes and still managed to be off the gate on time.
DMI
 
stratosphere
Posts: 1060
Joined: Sat Sep 22, 2007 12:45 pm

RE: "Rebooting" The Aircraft.

Sat Oct 17, 2009 12:15 am

In my experience I found it much more common to "reboot"an A320 than a 757. The airbus for some reason has a lot of nuisence messages that can be easily cleared by pulling a curcuit breaker and resetting it or in some cases a complete shutdown of electrical power and restarting it. Bad gate power is problematic for all electric airplanes. I remember an A320 where we had all kinds of problems we could not get a handle on we changed from gate to APU power and still had major problems finally I told the crew to start an engine and all the problems disappeared.
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: "Rebooting" The Aircraft.

Sat Oct 17, 2009 8:16 pm



Quoting Stratosphere (Reply 25):
In my experience I found it much more common to "reboot"an A320 than a 757.

The 757/767 were still remarkably analog airplanes. I *hate* troubleshooting indication problems on 757's because the wiring diagrams are just a festival of relays...rather than use a computer, they basically did analog logic with many of the systems. As a side effect, they're probably subject to a lot less computer issues than a more centralized architecture like an A320.

Tom.
 
LMP737
Posts: 4800
Joined: Wed May 08, 2002 4:06 pm

RE: "Rebooting" The Aircraft.

Sun Oct 18, 2009 4:11 pm

On the 777 my experience has been when there's an issue it's usually real and not some "anomaly". With the 757/767 a lot of times powering down the aircraft can clear a fault. With a relatively simple aircraft like the 80 there are very few situations where a "reboot" will happen.  Wink

Quoting AAR90 (Reply 9):
The MD90 general rule of thumb --which we pilots tried to strictly enforce-- is that once on acft power do NOT allow ground power cord to come anywhere NEAR the acft ! ! ! Once we got that rule more generally applied, the need to "re-boot" almost disappeared.

The best "reboot" for the 90 was to return them to the lessor.  Wink Of course the amount of OT went down when that happened.
Never take financial advice from co-workers.
 
kimberlyRJ
Posts: 249
Joined: Thu Mar 06, 2008 7:35 am

RE: "Rebooting" The Aircraft.

Wed Oct 21, 2009 1:32 am



Quoting Challengerdan (Reply 1):
When I work on DH8, or when I used to work on Lear 35s, you don't need reboots, but then there is not much computing power involved either

I fly quite a lot on the FlyBE Dash 8’s and I about 25% of the time the aircraft need a reboot, normally moments before P&S commences.

KimberlyRJ

Who is online

Users browsing this forum: Yahoo [Bot] and 4 guests