A320 wiper kept running

[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]

Originally Posted by oceancrosser:8057390

Originally Posted by 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.

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.

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

[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:

Originally Posted by DozyWannabe

(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.