That GPS antenna failure on a King Air 90 cost me 3 hours of troubleshooting

I had a King Air 90 come in last Wednesday with a total GPS signal dropout (you know, the kind that makes the panel go quiet). Turned out the antenna on the roof had a tiny crack from a hail strike nobody caught, and it was letting moisture seep into the connector over time. I finally found it by isolating the coax with a multimeter and swapping in a spare antenna from the shelf. Has anyone else dealt with water damage in those top-mount antennas (the older BendixKing ones) that just looks fine from the outside?

2 comments

2 Comments

the_jordan1mo ago

Yeah moisture in coax is usually the issue but that's a lot of effort for a simple antenna swap.

cole9941mo ago

Honestly I heard some guys say you can dry out wet coax with a hairdryer but that sounds sketchy.