A 320 CB reset guide
 

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

Thanks in advance.

QRH - Tripped c/b re-engagement 2.34 and computer reset procedure also in QRH 2.34.

Also in FCOM 3.04.24.

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.

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

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 (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.

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)

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?

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.]

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

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.

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.

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 ....

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

Cheers Metro man

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
Kaype

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)

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.

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.

Cbs..
 

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

Nick 1

Ah, one of those favourite cautionary tales, trotted out to back up an instruction of "don't touch that!"

Gibson's dive
http://en.wikipedia.org/wiki/TWA_Flight_841_(1979)

National Airlines DC-10 "pull the CB for N1 tach"
http://en.wikipedia.org/wiki/Nationa...ines_Flight_27

It is important to separate the folklore from the actual accidents. As alluded to above, the NTSB investigations were not beyond reproach. In the 727 slat incident, there was a presumption of guilt of the pilot in command. A witch hunt. The NTSB hypothesis was not supported by the subsequent test flight. In the DC-10 incident, the crew were castigated for a failure of discipline. However, the investigation revealed that the fan resonance that caused the uncontained failure of #3 would have remained undetected and happened at some future time.

What is relevant to the topic under discussion is ... the 727 "C/B pullings" are not applicable. IF the crew had pulled the Slat C/B, they were disabling a warning/protective system. It was a system that had limited interrelationships with other systems.

The DC-10 incident is a little closer. The crew hastened the incipient failure of the #3 by doing something the system designer never intended.

Current generation airliners have dropped most 'trouble shoot' procedures in abnormal checklists. Philosophy now seems to be - isolate the fault, then (a) land at nearest suitable aerodrome or (b) if conditions permit with the system disabled, continue.

AFAIK, the reason for replacing a troubleshoot QRH with an isolate then land at nearest suitable is the increasing complexity of the electronic (read micro computer based) control and command systems.

Pulling a slat C/B just used to disable the anti-extend mechanism.

Do that on a current generation airliner and you might disable the stall protection system and force the FADEC onto channel A which the EEC #2 previously set as FAULT, so FADEC then defaults to N1 mode instead of EPR, now autothrottles not available, etc... if you get my drift.

The benefit of all the digital electronics in flight control computers, ADIRUs, brake control units, proximity sensor units, is that they can monitor other systems for faults and failures and modify their status to suit. The drawback is myriad knock on effects for seemingly 'unrelated' system due to a fail/fault in one system, that never existed in second gen airliners.

Pulling C/B in flight? Only if QRH says 'do it' in response to an ECAM/caution/warning.

Pulling C/B on ground to reset computers due to fault indications?
"Incredibly dangerous, never never never!" or
"Its on the ground, and this handy guide has not let me down yet!"

I think the answer is somewhere in between.

Unofficial pilot notes were a good resource for thinking pilots, and a potential trap for the foolish and impatient. But so 'last century!' You now have unprecedented access to first hand advice via that mobile phone in your pocket. Iridium perhaps? HF even?

Call base. Speak to an engineer that knows the system. If he/she says 'give it a try' then go ahead. If he/she is reluctant, then you would be a mug for following your 'pilot notes.'

Don't have the MEL infront of me at the moment, but from memory if ADIRU 2 is U/S, take off cannot be performed in Config 1+F. How on earth can failure of such a seemingly unrelated system have that effect ?

Answer - If erronious airspeed indications were recieved there is nothing for the flap overspeed protection to compare with, and the flaps could retract at the wrong time. One incidence of this happening I think.

What about those spurious ECAM warnings that occasionally come up and disappear all by themselves, also the STS message which pops up briefly but you are never quick enough to push the button to view it before it vanishes.

Welcome to third generation airliners.

How on earth can failure of such a seemingly unrelated system have that effect ?

Not speaking to the context, but this is the generic problem with applying the MEL to multiple problems out in the field ...

I was looking for a better version and I found an app that is available for both Android and iOS. ECAM Resets+ It appears to be kept very up to date and from what I can see completely reflects the Airbus fault-finding workflows.

Apple Store

Android Version

When you guys reset CBs do you enter the defect in the log and quote chapter and verse from the current revision of the AMM/TSM?
Because, when Engineers and Mechs get hauled over the coals by the national regulator and local quality departments because they didn't dot the 'I's and cross the' T's this sort of discussion really sticks in the throat! 🙄😞

Mmm, more like welcome to Airbus!!

Yes. eg “LGCIU 1(2) reset in accordance with QRH ref XYZ. Successful/Unsuccessful. Signed: Capt Roger Victor, Date:17th Dec. 1903”

Mobile Tech
try this. Usual caviats apply.

I can honestly say I've never seen a write up anything like that.

This one?

ELAC 1 PITCH FAULT displayed during F/CTL checks. Reset i.a.w QRH PROC successful, no further warnings.

We used to have “info only” write ups for that but pilots kept making too many mistakes, so now mx control needs to be informed, and they keep track. Don’t like not seeing the history in the book. Having said that, just found an “Info only” for an unsuccesful autoland (facepalm) on an airplane that flew for 2 more days without getting downgraded.

Hence is why the info only was banished where I came from with the 2nd generation of western trained pilots.

The guys were actually on the first courses but as bright-eyed FOs then.

Because info only means exactly nothing specific. For many years the QA, which is much more strict for MX than flight ops here, does not recognze a semi-writeup.

Either its there or not, if yes will be responded to. 'Recorded as per CAMO Manual'. No, does no work well on an outstation or chain schedule downroute unless CAMo Manual and TechLog procedures are ready for it. That needs a bit of forward thinking by the certifying NAA.

The administration part is a pain, not the procedure itself. With cloud TechLogs and electronic signatures this can be overcome but the RoI on that investment is hard to justify (not to calculate, rather to push past the CFO).

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Back in the early days of the A320 family there was a procedure to pull certain cb to extend the flight time on battery only to 60mins and the cb had yellow collars.Is this true or am I thinking of another bus?

Correct tubby. One of our fleet still has it (MSN 10xx). Not well understood by all on the fleet.

Thank you for the reminder jwscud. I had a break from the A320 fleet and when I went back the early sn aircraft had gone as had the collared cb on the over head panel.

LGCIUs, ELAC fault described by Flight Detent , BSCUs... they all require, by QRH, to write up the reset, even if successful. I think there's a couple more in there somewhere