Had a radio altimeter go nuts on a King Air in Billings last winter. The fault code kept pointing to the antenna, but it was the indicator head the whole time.

Spent two full days chasing that ghost, swapping the antenna twice and checking every inch of coax. The intermittent failure only showed up below 500 feet, which made testing a real pain on the ground. The manual's troubleshooting tree was useless. Ever since then, I don't trust the fault isolation guide for those Honeywell units at all. What's the most misleading fault code you've ever gotten stuck on?

2 comments

2 Comments

simonlee28d ago

Sounds like my own troubleshooting skills on a good day.

oliviabarnes27d ago

Tell me about it... got a "check engine" light that swore up and down it was an oxygen sensor. Replaced two of those before finding a chewed-up wire behind the firewall. The manuals just want you to throw parts at the problem until it sticks. Sounds like you and @simonlee are in the same club of chasing ghosts the hard way. Never trust a fault code that points to the shiniest, most expensive part first.