Field replacing an alternator

While I'd hoped to post some Oshkosh related items during the trip, that...um...never happened :-)

The trip great as usual. We stopped in a few new places this time which meant we found a total of three new airport dogs to pet. No new airport cats to report though.

Everything was going well with the airplane until approximately 50 miles from Oshkosh when I notice a low voltage indication on the engine analyzer. I go through the drill of cycling the alternator but nothing changes...still reading right at 12 volts where it should be 14-14.1. At this point, I'm not too terribly worried since I recently installed a brand new battery and it's a wonderful VFR day. I do, however, shut down COM2, transponder, and the DME. When arriving at Oshkosh, one never knows when you might be required to hold due to arrivals being temporarily closed.

All goes smoothly with the arrival. Well, there was a Cirrus pilot who got a little concerned (unnecessarily so) about the tight arrival spacing. I was #2 in our flight of 6 and tower called the base turn and cleared my friend ahead of me to land. All of a sudden, the gal in the Cirrus, on maybe a 2 mile straight in final (likely an IFR arrival), says to the tower "You can't do that, I'm on final...I'm going to have to do a 360". Tower responds with "Mam, unless you see something I'm not, I don't see any issues here". Never mind that her doing a 360 in either direction would have been a bad idea due to the current arrival flow. I'm listing to this as I wait for tower to call my right base and clear me to land on 27. My brother picks up the Cirrus, we extend somewhat downwind until tower calls our base and everything works out fine. Sure, the spacing was tight...if this had been a normal airport but this is Oshkosh, you're expected to land on the numbers at the same time someone else is touching down maybe 2000 ft. in front of you. Ah, but I digress...

We setup camp in the North 40 and the next day, I start to investigate our alternator problem. It turns out that the ring connector to the main output stud had broken off due to being old and somewhat rusty. After breaking off, it sat there and arced such that the stud was worn approx. a third of the way through. The stud was also very loose. And, to add insult to injury, we found a crack in the alternator housing. End result: we decide to replace the alternator. It may very well have been the original and I know it had been rebuilt at least once in it's lifetime.

Fortunately, I have a friend who lives about an hour away from Oshkosh and who does a ton of his own maintenance. He is also logging time towards becoming an A&P. He shows up with tools in hand and the first thing we do is crimp on a new ring connector. I then spend a couple hours visiting the vendor exhibits and decide on buying a new Plane Power alternator. Yikes, $450. Ah, but it comes out of the partnership maintenance fund so it's "free"...as in "already paid for". Very cool :-)

The next day, we have the alternator installed and I crank up the plane and verify that it puts out 14 volts with everything electrical turned on. Life is good. It gets even better though as I have another friend who is an A&P and he shows up for a party the next night and says "I understand you need a sigh off for an alternator installation". Why, yes...yes I do. We wander over to the plane, he takes a look, and writes up a logbook entry for me. It sure is nice to have friends in aviation.

Just getting started...dropping the lower cowling:


The installation in full swing:

The rest of the show was great and the trip home uneventful with the alternator outputting it's normal 14-14.1 volts the entire way home.