How many people lost an Alternator/Voltage Regulator in flight?

[Yetti]

I noticed that the Mooney Eagle has the wiring for the back up alternator.    It would probably be 4AMU to add it.     Realize the Eagle has two batteries to choose from. 

[LANCECASPER]

Just now, Yetti said:

I noticed that the Mooney Eagle has the wiring for the back up alternator.    It would probably be 4AMU to add it.     Realize the Eagle has two batteries to choose from. 

If you end up doing your avionics upgrade you also might have another option - there's a small B&C alternator that can go where your vacuum pump is now. It provides 20 amp continuous and 30 amps max for essential things. In my Acclaim it can run the things on the Emergency BUS and it was installed at the factory. The alternator isn't listed specifically on the STC but there have been examples of 337s where it has been added, possibly with a field approval.

Just making sure that both of your batteries are (1) Concordes and (2) have good capacity left makes flying with one alternator a little less worrisome.

[Fritz1]

lost an alternator in a G-model about 30 years ago, circuit breaker fell apart, VFR, plugged aux battery pack into cigarette lighter port and completed flight

[Fritz1]

like the idea of the small backup alternator, the full size second alternator is quite heavy and right at the prop, may have to bump up the charlie weight, need second shim on prop, second belt has drag, not sure all that can be done for $4000

[PeteMc]

I lost a section of my Voltage Regulator once just after my initial call to the Danbury Twr (DXR).  Lost all comms, but gear, etc. was still working and on a VFR day. 

[N201MKTurbo]

I have had 3 alternator failures during flight. And one voltage regulator failure. Two of the alternator failures were caused by a broken field wire and one was from a bad brush holder. All happened in VFR conditions, the brush holder happened on an IFR flight. For all of the alternator issues, I landed and fixed it. For the VR issue, I landed and bummed a ride home and returned with a new VR and fixed it.

When my VR quit, I landed at Ramona CA. After I figured I couldn’t fix it, I walked into the FBO and asked everybody in the lobby if anybody was going to Phoenix? A young guy with a Bonanza said he wanted to do a practice IFR flight and would take me home. That’s a 3 hour round trip. He took me right to my hangar. I offered him fuel money, he refused to take it. I love GA.

[Yetti]

9 minutes ago, N201MKTurbo said:

I have had 3 alternator failures during flight. And one voltage regulator failure. Two of the alternator failures were caused by a broken field wire and one was from a bad brush holder. All happened in VFR conditions, the brush holder happened on an IFR flight. For all of the alternator issues, I landed and fixed it. For the VR issue, I landed and bummed a ride home and returned with a new VR and fixed it.

When my VR quit, I landed at Ramona CA. After I figured I couldn’t fix it, I walked into the FBO and asked everybody in the lobby if anybody was going to Phoenix? A young guy with a Bonanza said he wanted to do a practice IFR flight and would take me home. That’s a 3 hour round trip. He took me right to my hangar. I offered him fuel money, he refused to take it. I love GA.

Over achiever.   

[201er]

1st time was on my very first night cross country (with instructor). The instructor was so incompetent that he had no idea the entire time and I was just a newb, what would I have known at that stage? The tower was having a very hard time making out the radios at the out and return destination. Coming back to the uncontrolled home field, the moment the wheels touched the ground, everything in the cabin suddenly went dark. For a moment I thought we crashed. Then I realized the battery died. The alternator was already failed most of the flight long. I realized that if it the battery gave out any sooner, we wouldn't have been able to turn the airport lights on and would have been no electric trying to land some place. The instructor's inaptitude inadvertently made that first night cross country one of the most valuable and memorable lessons 

Another time was acting as safety pilot for simulated instrument flying in the owner's plane at night. Pilot puts the wheels down and then notices low voltage. So, he elected to discontinue the practice approach, leave the gear down, turn off everything but essentials, and return to his home field.

One alternator loss in my Mooney was due to voltage regulator failure but it wasn't a memorable occurrence. 

The other one was IFR enroute to Cuba but it happened over central Florida. I elected to continue to Pompano Beach and try to get it serviced there. Descended below the clouds, cancelled IFR, turned off non-essentials, continued to Pompano. I let the tower know on initial call that I was having electrical problems so they would clear me to land early in case I lost comms. After landing, the radio was barely strong enough to get taxi to maintenance. 
 

 

Edited December 3 by 201er

[Yetti]

41 minutes ago, LANCECASPER said:

If you end up doing your avionics upgrade you also might have another option - there's a small B&C alternator that can go where your vacuum pump is now. It provides 20 amp continuous and 30 amps max for essential things. In my Acclaim it can run the things on the Emergency BUS and it was installed at the factory. The alternator isn't listed specifically on the STC but there have been examples of 337s where it has been added, possibly with a field approval.

Just making sure that both of your batteries are (1) Concordes and (2) have good capacity left makes flying with one alternator a little less worrisome.

There is an extra spot for a breaker "alt field" and the wiring is in the wiring harness.     So if it appeared in the plane, one must assume it was added at the factory.

I did lose a Voltage Regulator in the F.   I had rebuilt the alternator harness when I first got the plane so knew that was not it.   Replaced the brushes in the Alternator as a first step.   Then Replaced the VR and all better. 

[varlajo]

46 minutes ago, LANCECASPER said:

there's a small B&C alternator

I looked into that one, but it seems like it is designed specifically for Continental engines. Does anyone have experience matching it with IO-360? 

[LANCECASPER]

3 minutes ago, varlajo said:

I looked into that one, but it seems like it is designed specifically for Continental engines. Does anyone have experience matching it with IO-360? 

Yes, I mentioned it for @Yetti who has an M20S with an IO-550 Continental.

[PT20J]

It seems from various posts here that the most common failure mode is a broken field wire. I have reinforced the wiring to the alternator to reduce vibration stress and I inspect it every time the cowling is off. 

Second most common problem seems to be voltage regulators. Mooney used different regulators over the years. I have a suspicion that the newer regulators may be more reliable, but I don’t know for sure. My 1994 MSE has a small Mooney brand. No idea who made it for Mooney, but it’s about the size of a Zeftronics. 

[201Mooniac]

35 minutes ago, varlajo said:

I looked into that one, but it seems like it is designed specifically for Continental engines. Does anyone have experience matching it with IO-360? 

It has been installed on Lycomings as well and I'm currently speaking with B&C about installing it on my IO-360-A3B6D.  It will require approval but I think I found a DER to enable that.

[Yetti]

25 minutes ago, PT20J said:

It seems from various posts here that the most common failure mode is a broken field wire. I have reinforced the wiring to the alternator to reduce vibration stress and I inspect it every time the cowling is off. 

Rebuilding the alternator wire harness should be on everyone's next annual if it has not been done since it left the factory.     The ground wire is very easy.    My field wire had broken strands going to the butt connector.    properly staking on a new terminal for the B+ wire.  Mine was loose in the connector.   along with the landing light wires.    If not properly tied to the engine (most are not)  all these wires are flapping along in a 100 mph breeze. 

[Jeff Uphoff]

I lost the generator in my old M20C many years back. As luck would have it, I was heading to Stockton, California, so I landed and taxied in to Top Gun and ordered up the alternator-conversion STC.

Hard to have a more conveniently timed major failure than that...

--Up.

[N201MKTurbo]

1 hour ago, Yetti said:

Rebuilding the alternator wire harness should be on everyone's next annual if it has not been done since it left the factory.     The ground wire is very easy.    My field wire had broken strands going to the butt connector.    properly staking on a new terminal for the B+ wire.  Mine was loose in the connector.   along with the landing light wires.    If not properly tied to the engine (most are not)  all these wires are flapping along in a 100 mph breeze. 

When I rebuilt my engine, I replaced the starter wire, the alternator wire and the field wires. And the P-leads.

If nothing else, it looks way nicer than those old ratty, greasy wires.

I had to borrow the hydraulic crimper from my electrician friend.

[N201MKTurbo]

1 hour ago, Yetti said:

 flapping along in a 100 mph breeze. 

Man, your plane is slow….

[EricJ]

I've had the alternator fail twice;  once from a broken field wire and once from the ground wire to the brush assembly breaking.   Both were easy fixes.

[varlajo]

2 hours ago, 201Mooniac said:

It has been installed on Lycomings as well and I'm currently speaking with B&C about installing it on my IO-360-A3B6D.  It will require approval but I think I found a DER to enable that.

Awesome!! Would you mind if I stopped by to have a look once this is done? 

[Hank]

I was flying IFR this summer, fat and happy at 6000' over East Tenn. and talking to Memphis Center. Came time to descend, I tried to ask and my G430W reset itself when I hit the PTT to ask for lower. It eventually finished and I heard chatter, so I tried again with the same results.

So I tried Comm 2, a King unit, and it reset itself to 120.0. So I set 7600 in the transponder and descended anyway, way late by now requiring me to orbit my destination ti reach pattern altitude. Flaps went down slowly, gear had to be hand-cranked, 52 turns down below my left knee. Guys ran out of the FBO when I stopped, and the local police were sad to not help with a dramatic rescue.

It was just a broken field wire. The rental car home from my ~90-minute flight cost 3X my repair bill.

If you've never done anything to your alternator, and don't see anything in the logbook, check it soon.

[Yetti]

1 hour ago, N201MKTurbo said:

Man, your plane is slow….

I was taking into account the drag associated with air going in the cowl, across the cylinder heads, down through the cooling fins circulating around the low pressure area and then out the lower cowl. 

I used the hammer crimper on the big lug.    Use what you got.

I am finding there is nothing slow about the S model.  Even dialed back to 11GPH it is going faster than the F.    I went up yesterday because it was a nice day and in a blink of an eye I was already to Lake Somerville while I was still dialing everything back. 

 

[201Mooniac]

54 minutes ago, varlajo said:

Awesome!! Would you mind if I stopped by to have a look once this is done? 

Presuming I can get it done, you are more than welcome to see it.  My IA is checking for clearances in the next couple of days and then I will attempt to get the DER to do the paperwork.  I'll let you know how it goes.

[EricJ]

It seems to be a good idea to inspect the wires at the alternator whenever the cowl is off.    You may be able to stay ahead of a broken wire that way.

 

[Niko182]

I have 2 spare voltage regulators for the R/S models because I've lost 2 voltage regulators in flight. I literally just sold 1 because a fellow mooneyspacer had his lost in shipping so I sold one but I'd recommend having a spare one if you can.

[Lax291]

Picked up my plane with an instructor for transition training, did about 3hrs the first day.  Set off to fly up the East cost from FL and about 3hrs in we see the alternator annunciator light.  We land, find maintenance and they identify a wire that's pulled away from a terminal on the alternator.  Replaced it, and we're back off and heading home.  1.5hrs later the light comes on again, land safely and the alternator needs replacing. The scramble began to get a replacement overnighted for Saturday morning delivery.  

All's well that ends well and I really appreciate that happening (even though it added more expense and delay than expected).  Was able to experience the failure with my CFII who is an airline pilot with thousands of hours in his Mooney, and saw that he was cool as a cucumber the whole time.  Also gave me a quick introduction to airplane ownership from shelling out unexpected AMUs to having to be flexible with your plans because things will happen.