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A 320 CB reset guide

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A 320 CB reset guide

Old 10th Nov 2008, 17:01
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A 320 CB reset guide

Anyone have a link to an A 320 CB reset guide?

Thanks in advance.
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Old 10th Nov 2008, 19:07
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QRH - Tripped c/b re-engagement 2.34 and computer reset procedure also in QRH 2.34.

Also in FCOM 3.04.24.
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Old 10th Nov 2008, 23:18
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There is an unoffficial, uncontrolled guide to resetting CBs inorder to recover computers which fail. It's something passed on from one pilot to another rather than company issued. Useful, but obviously at your own risk.
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Old 11th Nov 2008, 12:42
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Useful, but obviously at your own risk.
And your passengers' risk, and that of your crew. If it ain't official, don't reset it - you have no idea what can of worms you will open.
Metro man - which airline do you work for? I would like to avoid flying with them.
TP
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Old 11th Nov 2008, 14:32
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I have both the FCOM and the Unofficial Guide infront of me at the moment.
The Unofficial Guide states at the bottom of each page; " This is not an Airbus approved document and is provided for interest only. Use at your own risk."

The guide does exist. Obviously the FCOM is the first place to look and it states
On the ground, almost all computers can be reset, and are not limited to the ones indicated in the table
(3.04.24 P2)

The FCOM gives warnings as to which computers must never be reset, and limits inflight resets to those listed in the tables. It also cautions "Before taking any action on other computers, the flight crew must consider and fully understand the consequences.

The Unofficial guide has a procedure for resetting the HF radio; "Pull & reset the following CB - HA14". I can't find this in the FCOM, but would probably try it.

I am well aware of what can happen with CB resets. Anyone remember a B727 where the crew pulled the slat CBs and cracked a notch of flap to improve cruise performance. All OK until the flight engineer came back, noticed the breakers were out and reset them. Something about the aircraft rolling inverted and diving supersonically ?

Going through these threads I read of someone admitting to going into the avionics bay and re-racking flight control computers !!!!!

Obviously no substitute for controlled, up to date information from the manufacturer, which they take responsibility for.

Anyhow, I'm only an F/O. Captains decision to reset not mine.
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Old 12th Nov 2008, 17:27
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Going through these threads I read of someone admitting to going into the avionics bay and re-racking flight control computers !
Having worked as an ground engineer on the A320 since 1988, I can say that there is no reason to ever rerack a computor on the A320. I very rarely visit the avionics bays (once a year?). But resets of cbs are very effective on the A320. When you reset the cbs, the fault clears, the computor does a power up test, and if it does't pass the defect reappears.
There are only two systems where I downpower the aircraft. One is CIDS, because there are so many cbs it is easy to miss one, the other is GPS. I find GPS cb resets don't work.
One thing to remember is that sometimes the FWCs will store the fault, and may need resetting to erase the cleared fault. These computors have big capacitors in them and the cbs need to be left tripped for SEVEN minutes, a quick reset does nothing at all as the capacitors keep the power on.

By the way other aircraft are different. On the B777, cb resets may clear the defect, but usually the fault remains on the Status page. You have to do the MAT test to clear the message. (and most of the cbs are downstairs)
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Old 13th Nov 2008, 01:02
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I haven't seen the unofficial guide but I would be very cautious using it. At one time when the A320 was a new model Airbus used to publish a Service Info Letter that provided all the CB resets. They stopped supporting it in the late 90's believe. There has been some talk recently about resurrecting it and I think they have for the 318 fleet but that's as far as it went.

Were you curious about a particular reset?
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Old 13th Nov 2008, 01:24
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Quote from Swedish Steve:
Having worked as an ground engineer on the A320 since 1988...
[Unquote]

Those were the days! Even we pilots got to know many parts of the CB panels like the back of our hands. It was often the only way of getting home (from places like TCI) in the early summer of that year. Not many Swedish Steves around in those days...

All he says makes absolute sense, and explains why so many of our FWC (and FMGC?) resets were unsuccessful.

[Sorry, couldn't resist this one.]
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Old 13th Nov 2008, 08:04
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Cb..

Quote [And your passengers' risk, and that of your crew. If it ain't official, don't reset it - you have no idea what can of worms you will open.
Metro man - which airline do you work for? I would like to avoid flying with them.
TP]

Maybe an airline where the CEO is happy to have some pilots with little airmanship , that bring the vessel back to home after a small comuter reset ,
instead to wast money waiting for the Mec. to do the same operation.

Nick 1
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Old 13th Nov 2008, 09:13
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I found out long ago the risks involved in using uncontrolled material. I was a flight engineer on a military ac at the time. Anyone who thinks a little airmanship to get the ac home is a good Idea should think hard about the consequences of it not working as described due to the 50 SBs implemented since the unofficial guide was written. For me, Airmanship is not the right word here. Foolhardyship is more appropriate.
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Old 13th Nov 2008, 09:55
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If anyone would like a copy PM me your email address and I will foward it to you. Those critical of it will have a chance to examin it and point out any errors or problems that could result from its use.

There is much unofficial study material available from reputable companies for those wishing to study aircraft systems. Most pilots I know have a folder containing information such as enroute radio frequencies, ATIS frequencies, phone numbers, conversion charts, route notes, where to find stuff in the FCOMS (eg. manual engine start) etc. The presentation varies between ready to publish, and my Grannies recipe clippings.

For FL to Metre conversions, use of the company supplied chart is mandatory, no personal documentation allowed. Has anyone here ever had to convert from imperial to metric or vice versa. Where did you get the formulae from ? One kilo is 2.20462262lbs according to Google, was that the rate you used or did you get it somewhere else, an approved source, or did you already 'know' a kilo = 2.2 lbs ?

Back in the early days of aviation, a pilot used to make his own route notes. He was forever being asked to lend these out and decided to publish them. "Hey Jepp, can I borrow your notes ?" was a much used phrase.
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Old 14th Nov 2008, 22:43
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airmanship

I thought that was the whole idea, use superior airmanship to bring the aircraft back if you can. Unless of course you are broken in some exotic sunny spot, then make hay ....
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Old 14th Nov 2008, 23:05
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air france has a quite nice computer reset list including time to wait for the self test after reset of the circuit breaker. but it is in French
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Old 15th Nov 2008, 00:36
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a marche...
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Old 15th Nov 2008, 07:20
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Cheers Metro man
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Old 17th Nov 2008, 06:24
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On ground Reset.

You can refer TSM 24-00-00 810-818 TASK FOR C/B COPMUTER RESETS .However TSM is only meant for resets on grnd.
Rgds
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Old 17th Nov 2008, 06:33
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A320 C/b Reset

You can refer TSM 24-00-00 810-818 TASK FOR C/B COMPUTER RESETS .However TSM is only meant for resets on grnd.
Rgds
Kaype
(corrected)
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Old 17th Nov 2008, 10:45
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Nick 1 and Robere35: I'm with FE Hoppy on this one. After four years on the A320 I wouldn't start pulling CBs in flight unless following the Airbus reset table. Experimenting with a few resets isn't "airmanship", it's asking for trouble. On a B737 perhaps, but the systems on an Airbus talk to each other, so by rebooting one computer you may interrupt signals to several others. A lot of clever people have put the manuals together (very badly, I'll grant you!) so that, if a system can be recovered you can attempt a reset, if not you leave it alone and work with the remaining channels/backups.

I would link your attitude to that of the type who considers the use of speedbrakes a personal failure.
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Old 17th Nov 2008, 14:28
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Anyone remember a B727 where the crew pulled the slat CBs and cracked a notch of flap to improve cruise performance. All OK until the flight engineer came back, noticed the breakers were out and reset them. Something about the aircraft rolling inverted and diving supersonically ?
I have no recollection of the event, however I remember one B727 crew that experienced uncommanded and asymmetric slat extension in cruise. Aeroplane promptly rolled on its back, went supersonic in dive and was severly bent during recovery. Crew was officialy blamed for tampering with slats' CBs in order to get improved cruise performance. The problem with the story is that (according to Stanley Stewart) there was a test flight that was to verify if there was really performance improvement with flaps slightly down during cruise. There was no improvement however, but empty 727 couldn't climb to its normal cruise level.

If we are both talking about Gibson's dive, we're talking about the same thing.

Now don't use this story as an excuse to tamper with your CBs during flight. The purpose of the circuit breaker is to protect the electric circuit from overload and consequent overtemperature which can lead to fire. They were not designed to be used as switches, however there's no evidence, anecdotal or otherwise, that occasional reseting of Airbus computers via their CBs has negative impact on CB's longevity or proper function. CB pull-pushing that is not covered by the written (and properly approved) procedures is best left to test pilots only. On any aeroplane, not just Airbus. The pilots of Valujet's DC9-32 that ploughed the runway at Nashville on Jan 07 96 were very creative with their CBs. And very lucky too.
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Old 17th Nov 2008, 17:33
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Cbs..

CleanSpeed,
i was speaking to reset the CB on ground . I's clear that in flight it is another story.

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