A320 wiper kept running

[IFLY_INDIGO]

A A320 flight took off yesterday in light rain in Mumbai with wipers on. after takeoff, captain's wiper failed to turn off. crew returned back to Mumbai.
on ground AME found a faulty wiper converter.

[mono]

Seems a bit drastic!

Surely they could have pulled the CB to stop it running.

[I-2021]

Seems a bit drastic!

Surely they could have pulled the CB to stop it running.

Quote on that. Indigo some more facts that lead the crew to take this decision ?

[PENKO]

Ah but this is an airbus you see, pulling a CB for the wipers might cause the engines to flame out! Well...maybe not that drastic, but we are strongly discouraged to pull CB's that are not on the reset list. There is no CB list anywhere to be found in the FCOM.

[rudderrudderrat]

There is no CB list anywhere to be found in the FCOM.
"Hello Dave, I've turned your wipers on for you."
"Hello Dave, my angle of attack probes are all saying I'm about to stall at Mach 0.8 and 250kts so I've pushed the nose down to -10 degs. You won't be able to control me unless you turn me off. Oh and by the way, there is no off switch fitted."

[speed freek]

What was the forecast for destination? The PF's wiper (in this case, the captain) is required for CAT II and III.

[IFLY_INDIGO]

In his explanation, captain mentioned that fact that the max speed with wiper on is 230 kts. so he could not continue to his destination New Delhi (departure Mumbai). Also, he said that wiper motor might have turned hot and led to the fire. so he decided to return. on CB pulling, there is no such procedure. so he refrained from experimenting and turning the flight deck into a lab when there was no such urgency.

[Dan Winterland]

230 knots in our FCOM.

[clark y]

Don't forget how much damage a wiper may do to a dry windscreen. Not to mention the distraction factor of the thing.

[Cough]

Agree with Dan...

[FlightDetent]

What was the forecast for destination? The PF's wiper (in this case, the captain) is required for CAT II and III.

Interesting train of tought. What does the QRH say, and AFM more importantly?

[TopBunk]

It's about 8 years since I last flew the A320, but I agree about the 230kt limit for the wipers.

Secondly, I don't believe that there is a QRH /ECAM for this as it is a pilot selectable item.

Thirdly, I can see nothing in the MEL (albeit not up to date) relating to dispatch restrictions.

To me, the crew on the day seem to have made a perfectly sensible decision, probably after consulting his Maintenance department, to discontinue the flight. I for one, wouldn't wish to test the reliability/endurance of a wiper motor for ~2hours on a dry screen.

[vinayak]

Pulling the CB out seems like a good idea...

Could it possibly have any other repercussion other than the wiper shutting off?

[oceancrosser]

The wipers on Boeing 757 are crap, rarely do they stop when switched off, but usually one of them keeps on banging for another 10-15 sec. On one of my flights they did not quit, so the F/O (eventually) found the CB and pulled it. Quite distracting and incredibly noisy. Never seen a speed limit for them though. :ugh:
The old pneumatic "rain removal" system on the DC-8 although very noisy was probably better.

[IFLY_INDIGO]

Question is : when do you use 'out of the box' solutions, like pulling the CBs not suggested by the manufacturer?

I would reserve the 'out of the box' solutions for the scenarios where there is no other way out.

In this particular case, returning back to the airport was the easiest, safest, legal way out. why not?

[DozyWannabe]

Question is : when do you use 'out of the box' solutions, like pulling the CBs not suggested by the manufacturer?

In modern aircraft, particularly those with FBW systems, I'd have to concur with "never - unless it is literally a life-or-death situation if you don't, and even then, you'd better be bloody sure".

The way I see it, the airlines demanded that these aircraft become more complex in terms of systems, leading to fewer crew-serviceable scenarios than there once were. They also made the decision to rely more on SOPs in order to mitigate risk. Consequently, once in a while they're going to have to take an RTB due to something as simple as a non-cancelling windscreen wiper, and accept that the Captain's RTB decision was completely justified.

[vinayak]

IFLY_INDIGO

If this happens again on your flight, I hope not... You'd consider diverting or pulling out the CB

These days our loads are rubbish but, imagine a DEL - CCU or DXB - HYD sector where we are tankering crazy amounts of fuel and overweight landing would have to be done.

Or even worse, we'd have to burn off those 3-4 tons of fuel.


Do you think, perhaps pulling out tthe CB might be a good thing to do?

[stilton]

Unintended consequences.


Unfortunately you never know what else is on the circuit when you start pulling and /or resetting breakers without a specific procedure.


One of our crews lost both internal speed cards on each one of their EADI's (B757) in fact each one was red flagged.


In response and quite reasonably they reset the 'Speed Card' CB's on the overhead.


They were very surprised to then see the RAT extend where it stayed for the rest of the flight, naturally as it cannot be retracted once deployed.


Unbeknownst to them or anyone else in flight ops this is how Maintenance performs a RAT test and the circuit is shared with the 'speed card'


It did fix the speed card though.. :eek:

[seventhreedriver]

I'd start by looking in the FCOM abnormal ops for solution. As there is none available for this kind of problem, I would start using common sense. As always, there are more solutions for a given problem, especially if it is not covered in any of the books in the aircraft... Although returning is a perfectly safe course of action, I would have tried pulling the cb for the wiper (undocumented procedure for an undocumented problem)... DODAR - letter O is quite important.

[Check Airman]

In response and quite reasonably they reset the 'Speed Card' CB's on the overhead.

Interesting story. Two Questions:

What's a speed card?

Is there a RAT CB on the 757?

[nitpicker330]

Wow, some really funny crap being written.

Firstly modern Airbus types ( the A330 and I'm sure the A320 is the same ) don't have circuit breakers in the cockpit, they are computer reset push buttons on the overhead panel.

Secondly, the CB for the wipers is located in the Equipment bay under the floor. I wouldn't suggest a Pilot go sniffing around down there in flight trying to find the correct one!!:D besides there is no drop down Oxy down there and you'd need to take a portable bottle to be sure.....:eek:

In my opinion a good decision to return and get it turned off before scratching the window or overheating the motor or driving the Captain mad with the noise!! .....:ok: ( not to mention the 230 kt limit as well )

[Check Airman]

Firstly modern Airbus types ( the A330 and I'm sure the A320 is the same ) don't have circuit breakers in the cockpit, they are computer reset push buttons on the overhead panel.What are things at the top of this photo?

Photos: Airbus A321-211 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Finnair/Airbus-A321-211/2134515/L)
http://www.airliners.net/photo/Finnair/Airbus-A321-211/2134515/M/&sid=588af24a94bf4e7326ea2d3c352b0cf1

[Back Seat Driver]

nitwit330 saidFirstly modern Airbus types ( the A330 and I'm sure the A320 is the same ) don't have circuit breakers in the cockpit, they are computer reset push buttons on the overhead panel
DOH wrong again!
Bwahahahaha.

[FLEXPWR]

Airbus does not say to forget using common sense and airmanship. And the circuit breakers are not in the avionics bay: they're right behind the FO's seat on panel 122VU, locations X12 and W12.

Pulling a CB for a windshield wiper is probably one of the options I would do even in flight, even if I may consider returning to departure airfield afterwards, depending on the circumstances (WX on arrival, impact on subsequent flights etc.)

Where on earth some people see no CB's in an Airbus? I hope a rated pilot can make the difference between a pushbutton and a CB... :ouch:

[stilton]

Speed card is the internal vertical indicated airspeed speed scale on the EADI
to the left of the attitude indicator.



Don't know if there's a dedicated RAT Circuit breaker.

[nitpicker330]

Ok I stand corrected however I did say in brackets that I was sure the 320 was the same. Apparently it's old technology!!

Certainly I was correct with regards to the super modern 330 !!:}

[vinayak]

http://pilotpitstop.com/docs/External%20Links/pprune/QRH%20Computer%20Reset.png

Nothing as such in the 330? Wow! Interesting :)

[nitpicker330]

Well if you look at the top of the page you paste it shows 318 319 320 321 BUT not 330

My 330 QRH calls those little things on the overhead panel Computer reset push buttons. THEY ARE NOT CIRCUIT BREAKERS...

Here is the same page from the 330 QRH:---

80.17A 330-3** QUICK REFERENCE HAND BOOK

ABNORMAL AND EMERGENCY PROCEDURES 15 FEB 13


COMPUTER RESET - GENERAL RESET OF COMPUTERS This table lists the computers that may be reset following abnormal behavior, or a detected fault. Most of the computers' reset capability is provided on the overhead RESET panel: Those with an asterisk* are reset on the system control panel. To reset a computer: ‐ Set the related normal cockpit control OFF, or pull the corresponding reset pb, ‐ Wait 3 s, if a normal cockpit control is used (unless a different time is indicated), or 1 s if a reset pb is used, ‐ Set the related normal cockpit control ON, or push the corresponding reset pb, ‐ Wait 3 s for the end of the reset.

WARNING Do not reset more than one computer at a time, unless instructed to do so.

The following table lists the various computers for which manual reset capability is provided: • On the overhead RESET panels, • On the system control panel. For each computer reset, the table lists the effects and/or precautions where applicable ("NIL" indicates no additional effects and/or precautions apply). ‐ A computer reset has to be attempted when: • recommended by an ECAM procedure or • recommended by a paper procedure. ‐ In all other circumstances, where a failure is suspected or detected, there is no specific recommendations as to whether a reset should be performed or not, except those where a reset is specifically forbidden. Manual reset on ground triggers complete power up test.

[nitpicker330]

Further more:---

Those Circuit breakers you mention, SFCC and ECU etc are not on the 330 overhead panel as such at all.

The Lower Avionics bay contains Circuit breakers on the 330 and that is where those SFCC and ECU circuit breakers would be located for ENGINEERING USE.

Monitored by the CBMU ( circuit breaker monitoring unit ) and available on the C/B SD page on ECAM.

There are also other cabin related circuit breakers in the cabin.

Ok, happy now...:ok:

[vinayak]

Huh? I did not say you were wrong to begin with. And yes, I can read - thank you! Nitpicker quit nit picking :P

An extract of the 330 QRH :)

http://pilotpitstop.com/docs/External%20Links/pprune/330%20Computer%20Reset.png


Also, there are some places where you'd need to pull out the CB it seems. But not as many as the 320... The 330 is a newer airplane, doesn't make the a320 ancient

http://pilotpitstop.com/docs/External%20Links/pprune/VSC%20reset.png


Everything is this post and any other post is to educate myself and not to accuse anyone of what they may or may not know. If any of that may have seemed misdirected to that effect, wasn't the intention.

[nitpicker330]

Ok fair enough mate. I was pointing out to backseatdriver in my post #29 that I wasn't wrong with respect to the A330, you got caught up in the crossfire!!

Truce :ok:

[oceancrosser]

Interesting story. Two Questions:

What's a speed card?

Is there a RAT CB on the 757?

On the B757 (RB211 version) the engine speed card supplies "Engine Running/Not Running" information to the:
Equipment cooling system
APU fire extinguishing
Fuel boost pumps
Power Transfer Unit
Ram Air Turbine
Angle of Attack probe heat
Pitot-Static probe anti-icing
Total Air Temperature probe heat
Flight Management Computers
Electronic Engine Control
Engine start system
Air cooling pack system.

And probably other functions as well.

Sorry Stilton, but the Speed Card has nothing to do with SPEED TAPE on ADI´s but all to do with engines and their control. Hence why the RAT drops when both CB´s pulled simultaneously, it thinks both engines have quit.

[nitpicker330]

Yes it was, apologies for the drift!! :E

[FLEXPWR]

Did it occur to anyone that resetting a CB for a wiper should be straight pilot decision making? Forget about computer reset tables, a wiper is not a computer....it's a wiper! It does not compute much, apart from OFF/SLOW/FAST which are mechanical (pilot) inputs to the electrical wiring.

Airmanship is the best computer in this scenario, and should dictate when resetting the CB is relevant or not (and especially for the not-computer equipment)

By the way, this situation should not be a reset, but a faulty system isolation by removing its electrical power supply (CB pulled) until the mechanics can have a look.

[DozyWannabe]

@FLEXPWR:

There was an earlier post in the thread which seems to have since been edited that implied that there was a list of circuits which could be pulled in flight and that the wiper motor CB was not on it. If this isn't the case, then I retract my earlier statement.

[nitpicker330]

FLEXPWR--- yes it's occurred to all of us. I was mistakingly assuming that the A320 was the same as the A330 in that we don't have C/B's in the cockpit to pull at all. Only computer reset push buttons.
On the A320 they apparently have C/B's in the cockpit and I guess there might be one for the Wipers, if so I see no problem pulling it out under those circumstances.

Don't confuse pulling/resetting a C/B with a A330 style computer reset button used in conjunction with the QRH reset tables.

[Airmann]

Anything that has numbers on it and pops out is a circuit breaker.

[stilton]

'Sorry Stilton, but the Speed Card has nothing to do with SPEED TAPE on ADI´s but all to do with engines and their control. Hence why the RAT drops when both CB´s pulled simultaneously, it thinks both engines have quit. '


Well thanks ocean crosser. That explains what happened to this crew then !


I stand corrected.

[F-16GUY]

The question in my head is, if you have the option to pull the C/B, where do the wipers stop. Do they stow as they would when working normally or do they just stop in the middle of the screen? If so, then your are still stuck with the 230 knot limit.

I have always been told that it is not my job to troubleshoot. leave that for the techs on the ground. Only situation where its ok to think out of the box is if you get something critical that is not described in the C/L.

[WhyByFlier]

Wipers in the MEL say check landing capability.

However in the air, provided you have rain repellant on the PF side, wipers are not a requirement for cat 2 or 3 (b) approaches.

QRH OPS-OPS-4:

WINDSHIELD WIPERS OR RAIN REPELLENT (if activated)......number required: 1 on PF side

You'd have to return if it wouldn't stop running - that's all there is to it - unless you're one of these believers in the 'grey area' - remember as a pilot you have all of the responsibility and none of the authority - the managers keep that for themselves - That's of course unless all bets are off - this isn't the case here.

[Ollie Onion]

I don't see what the problem is with returning?? It is all very well saying pull the CB to stop it, there is however NO published procedure to do this. Any what happens on final approach when you need to have them on again, do you tell the FO to hop out of his seat to click the CB back in??

I am a believer in pulling CB's if it is absolutely required even with no published procedure, but only in an emergency when no other option exists. In this case, however, there was no need to 'push on' and make up procedures. Just land back and get it sorted.

[IFLY_INDIGO]

a switch stopped functioning as it should.. probability is equal that another switch (CB) may function as it should NOT!

also think, how would you answer to the authorities and the airline, if pulling CB complexes the matter..

[Check Airman]

Interesting story. Two Questions:

What's a speed card?

Is there a RAT CB on the 757?

On the B757 (RB211 version) the engine speed card supplies "Engine Running/Not Running" information to the:
Equipment cooling system
APU fire extinguishing
Fuel boost pumps
Power Transfer Unit
Ram Air Turbine
Angle of Attack probe heat
Pitot-Static probe anti-icing
Total Air Temperature probe heat
Flight Management Computers
Electronic Engine Control
Engine start system
Air cooling pack system.

And probably other functions as well.

Sorry Stilton, but the Speed Card has nothing to do with SPEED TAPE on ADI´s but all to do with engines and their control. Hence why the RAT drops when both CB´s pulled simultaneously, it thinks both engines have quit.

That makes more sense!

[latetonite]

As there is no more common sense involved nowadays, people have to live with SOP's. In absence of a proper one, it will become an emergency.

[FLEXPWR]

@latetonite, well said, no more common sense involved...

Soooo don't pull the CB, fly for 45 minutes in IMC because the departure airport was below landing minima's and we need to return ASAP to the departure alternate, let the wipers run and scratch the dry windshield for 45 minutes, or wait for signs of smoke from the DC motors, then religiously apply the smoke checklist (several pages long), so at this point maybe the wipers CB actually do pop out on their own, maybe not! Let's declare an Mayday and discharge the portable extinguisher in the cockpit while wearing the O2 masks or the smoke hood (pick your preferred option, or follow your SOP's). Land after the 45 minutes and congratulate one another for a great day following SOP's to the letter, and prevent common sense interfering with the written procedure. :ugh:

That would be a nice scenario for a movie! :}

Of course the comparison is cheap, but lucky the guys on Apolllo13 tried to think outside the box!

Note: I am a firm believer in SOP's and comply everytime it is possible. But remember SOP's mean "standard", and no SOP's cover a wiper with a temper.

[mikedreamer787]

I've had a wiper stuck on after TO in moderate rain once.
Fortunately the rain was widespread so there was no w/s
damage after holding and returning to departure airport.

I looked for an appropriate c/b too but couldn't find any.

Engineer later told me as long as one observes the 230kt
limit the motor will continue to run without risk of burn
out in dry conditions. Any screen damage was moot as
we were always in rain at the time.

[tdracer]

As an engineer, having a flight crew experimentally troubleshoot a problem in a system they don't know or understand - instead of turning back and letting the pro's do it - scares the crap out of me.

13 years ago, an Alaska MD80 experienced a stab trim jam while flying from Mexico to Seattle. Instead of leaving things well enough alone and diverting, they tried to clear the jam by continuing to try alternate inputs into the stab trim.

Their uneducated troubleshooting caused the jack screw to fail catastrophically and the airplane did a nose dive into the Pacific from 18,000 ft. :mad:

The families of 88 people would rather they had diverted when they first experience the jam :ugh:

[westhawk]

Instead of leaving things well enough alone and diverting, they tried to clear the jam by continuing to try alternate inputs into the stab trim.

And not in consultation with mx control? Weren't they involved?

[latetonite]

Td.tracer:

If you engineers would have put some grease at that jackscrew before, the pilots would not had that problem in the first place.
Second, once that jackscrew was jammed, they had to try everything to get pitch control on the aircraft. Your suggestion to divert without any elevator control, is in our pilot's handbook rather difficult to perform.

[tdracer]

Second, once that jackscrew was jammed, they had to try everything to get pitch control on the aircraft. Your suggestion to divert without any elevator control, is in our pilot's handbook rather difficult to perform.


Read the accident report! They had control, it just took unusual control forces because the (jammed) location of the stab. If they had just left it the heck alone, they could have landed. The lawyers (who I hate BTW) had a field day.

Trying to fix the problem without understanding the problem caused the failure and resultant crash.

Oh, I doubt any engineers had any input into the extended lube intervals that allowed the jackscrew to fail. It was done by bean counters and bureaucrats (who I hold in similar esteem to lawyers).

[latetonite]

Have to admit I did not read the report. if they indeed had limited elevator control, the should have diverted.
Regarding the second part, I am not sure either how things go in your business. Were the engineers informed then NOT to perform certain items on the x- hour interval inspections, or do they just carry out a job card issued in the office somewhere?

[latetonite]

However, going back to the original topic, the story of the wiper, this is another reason just to inform the cabin crew nr. 1, and later in your broadcast to your 250 passengers, "We have a small technical problem."
Imagine you tell them you return to your departure airport, " cause a windshield wiper is not behaving properly.."

[FLEXPWR]

tdracer, it is not about experimentally troubleshoot, it is about isolating a faulty equipment.

What you are saying is that as an engineer (mechanic), you would leave the wiper run after the aircraft has landed until you browse through the TSM (troubleshooting manual)? Of course not. You get in the cockpit and pull the CB, then start troubleshooting. Nobody here claims to troubleshoot or fix the wiper. And I agree, returning is probably a good option, depending on many factors.

[DozyWannabe]

The point is that even if it goes against common sense, you do what the book says (unless to do so would endanger the flight). If you do what the book says, then the airline - and by extension your butt - is covered. If you deviate from what the book says and things go bad on you, then it's on your head.

[bubbers44]

I will bet the DC10 pilots who followed AA SOP's at ORD that day wish they would have done what the post crash SOP's were instead of the ones they used on their takeoff.

[DozyWannabe]

Not disputing that, bubs - hence the caveat:

(unless to do so would endanger the flight)

We're talking about a windscreen wiper that wouldn't shut off, not an engine separation!

Additionally, if AA (along with Continental and United) had stuck to the MD SOPs for removal and attachment of an engine then it wouldn't have happened in the first place.

[bubbers44]

I had electrical smoke fumes throughout the 757 departing MIA about 15,000 ft one day about a year after the SwissAir crash because of smoke near Halifax. We had not changed our checklist so made my own memory items to shut down non essential power.

Two weeks later after my report they changed the checklist to what we did. Sometimes you have to rethink how to make your flight safe because you are PIC and it doesn't matter if you followed SOP's or not because you are responsible for the safety of your flight.

It turned out the source of smoke was an oven on the non essential bus.

I know someone will post the PIC sentence and run with it but that is Pprune posting.

[DozyWannabe]

And that was good thinking, bubs.

I don't think anyone's advocating blindly following SOP in all circumstances here - something like smoke or an engine failure with unusual side-effects means that it's time to think carefully before following SOPs.

But in this case, if it's as simple as a wiper refusing to shut down after takeoff and the book says you leave the CBs alone and go back, then that's what you should do no matter how silly it may sound. And if the airline gripes, then you point to the book and say you followed procedure to the letter. For those that despair of SOP-centric culture, why waste an opportunity to hoist the suits by their own petard? ;)

[bubbers44]

DW, I agree, sometimes you do the SOP's because you are paid to do them. If safety is the issue, do what you feel is safest.

[mikedreamer787]

If safety is the issue, do what you feel is safest.

Yes. Its called airmanship.

[Chu Chu]

Seems to me there would be no way to tell why the wiper is continuing to run. It could be some thing like a short circuit or arcing contacts that would lead to worse trouble.

As I write this, I realize it may be an argument for pulling the breaker. (Or at least an excuse to. . . )

[Teldorserious]

I didn't know that the Airbus didn't have circuit breakers. Well, the good thing is that the pilots didn't wiggle the rudders to much on the emergency decent.