2016-02-24

Sedona Alternator Adventure

Electrical Failure on Approach

Approaching Sedona on a nice Wednesday afternoon, winds calm, approach a bit bumpy, but nothing excessive. On short final, just before the touchdown I noticed the alternator warning light flashing. This meant that the battery was draining and alternator has failed. I have recently went through a costly alternator repair (where the alternator was fine but the field wire to the alternator started exhibiting high resistance) so I thought that maybe this was connected to that repair.

Taxied to the transient parking, shut down, got out and saw that the alternator belt pulley failed causing the belt to completely slip in the tracks.

For a video that is completely out of focus, see below:

https://www.youtube.com/watch?v=kpSlpxwovIw

Field Alternator Repair

There were no mechanics available on the field, just fuel, but I got a phone number to a guy local FBO were using. Bob Luna arrived an hour later and said it was a good thing the belt did not fail because we would have to remove the propeller to fix that issue.

We took off the cowling and immediately noticed the solution. Bob removed the identical pulley from the other side which was powering the air conditioning compressor and replaced the failed alternator pulley. That meant I lost air conditioning but the airplane was charging its battery again 🙂

Pulley Replacement

Need to purchase a replacement and put it back on the air conditioning compressor. It is not obvious from the picture, but the pulley has a rubber insert that houses the ball bearings. The rubber insert and the ball bearings were nowhere to be found. Gravity ate them probably.

We fired the plane off, charging was fine, air conditioner belt was spinning a little bit but not too much. Bob was convinced it would not catch in anything around the engine and it was safe to continue the flight. We replaced the cowling, I paid Bob $60 and something extra on top of that and went in to find a room for the night, as it was getting pretty late.