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Would you depart with a probably faulty alternator?

This UK rag has a report on someone with a Saratoga who departed Calvi (Corsica) for the UK. He had to divert when it packed up properly enroute, and come back later with a mechanic and a new alternator.

He is asking: Should I ever have departed Calvi? Should I have diverted to
the nearest airfield? Should I have switched off the autopilot to preserve the battery? Should I have
also switched off the GPS 430 – and stay with map and compass? And should it have been wheels
down or not?

It’s a good Q. I suspect, given it was Calvi, that most people would get out of there to somewhere, anywhere, with some facilities and transport home.

Administrator
Shoreham EGKA, United Kingdom

Would have got out of Calvi; but routed to Nice the moment I had a problem.

Rochester, UK, United Kingdom

I’ve done it (a faulty generator not alternator). This was in the USA, somewhere in the desert, with the tumbleweed rolling past – it failed at an airfield that was pretty much unattended, in a Cessna 140.

I used the battery to start the plane, and once I had made my radio announcements, turned off the master switch and didn’t turn it on again until nearing the airfield near Phoenix which had a choice of mechanics to go to for a repair, so I could use the radio. Fortunately I noticed it when it failed so I didn’t end up flattening the battery, as I’d prefer not to use the Armstrong starter unless someone’s there to assist.

Really not a big deal in a simple plane with wall to wall sunshine. The cheaper version of the 140 (the Cessna 120) wasn’t even fitted with an electrical system.

Last Edited by alioth at 29 May 10:01
Andreas IOM

Well, this alternator was working when he departed. I’d have taken off.

Do Calvi have any engineering on the airfield? Even if they do, depending on the time of day or day of week, it might mean a few days delay just to show an engineer that your alternator is actually working, while you explain that it didn’t for a few seconds previously. I can imagine a shrug of the shoulders with a comment “Well, it’s working now!”

Turning off the 430? That would be an easy choice for me, as I’d have navigation available on my tablet. But I guess not such an easy choice if you’re reverting to a map and compass after years of using GPS.

Gear down? I think I’d have kept it up too, planning to put it down when power started to drop. But then I am confident in the free fall option on the aircraft that I fly, having often tested is as part of recurrent training.

What I do think I’d have done differently though is shedding more load. I’d definitely not used the autopilot, and even the radio/GPS I think I’d have told ATC that I will turn that off and check in again 10 minutes. That would mean I could turn the master off and preserve all power and then turn it back on to check in with ATC and check the GPS, then turn it off again. That would extend the power significantly. Though I’ve no idea how long the 430 would take to get a fix again in flight like that. Though ATC could have helped if it couldn’t get a fix.

A nav app on a smartphone would have helped a lot too.

EIWT Weston, Ireland

Depends on the engine and needed systems. With EFI/ECU and glass cockpit, no way. With steam gauges and systems, no problem.

The elephant is the circulation
ENVA ENOP ENMO, Norway

Would never do it exactly the way the pilot in the report did! This I can say for sure!

But I have to admit, that actually I have to add an “again” !!!

Have been in exactly the same situation about 4 years ago in my PA-46. Alt-light went on on the ground but turned off after cycling the switches. 20 Min into the flight (IFR in mostly VMC) the Bat-Warning went on. Took me 5 Min. to realize what just happens (“Ah, the light must be wrong…”). After that I did some things right, luckily: I lowered the gear and set first flaps. And I was able to tell the controller, that if I get silent I’l descent below FL100 on flight planned rout and land at the next suitable (VFR) field. That was easy because I was not over water in solid VMC. I landed on a field I knew from previous visits (of which I afterwards figured out it was closed by notam) and received a call from SAR on my mobile about 5 minutes after landing to check if I’m alright.

One important insight (because many are afraid of it): No negative consequences at all! Not even being questioned by someone. Landing on a closed airport was a total no issue in that situation.

Germany

Out of pure curiosity what is the largest bill that one might reasonably expect for having the alternator debugged and potentially replaced if it malfunctions whilst away from home?

(Let’s say for the sake of argument an alternator on a homebuilt with an O-320, stranded in the UK)

Last Edited by kwlf at 29 May 23:59

A Lycoming alternator is circa $500 USD, depending on type, but easy to install – belt driven on the front of the engine.

So an estimate of 30 hours labour would be… generous?

Last Edited by kwlf at 30 May 00:26

I think 30 hours to diagnose the problem and change every component would be nuts. 3 would be close.

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