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Had a weird GPS dropout over Phoenix last week that almost cost me a flight check

I was doing a post-install check on a Garmin GTN 750 in a Cessna 172. Everything looked fine on the ground, but about 15 minutes into the flight test, the GPS signal just dropped for a solid 30 seconds. No warning flags or anything. I landed, pulled the antenna, and found the coax cable had a tiny pinch where it passed under a seat rail. Not enough to short it, but enough to mess up the signal at altitude. Took me an hour to find it with a cheap VSWR meter. Has anyone else dealt with intermittent GPS dropouts that traced back to a dumb cable pinch like that?
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2 Comments
river351
river35121d ago
Nah, that's weak troubleshooting. A VSWR meter and an hour? Should have caught that on the ground with a continuity check before you even taxied. If you're blaming altitude for a pinch that's already there, you're just covering for a sloppy preflight.
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reeselewis
reeselewis21d ago
Saw a similar post on a avionics forum, those coax pinches are sneaky.
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