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Showerthought: The new Collins Pro Line 21 trainer at our hangar in Phoenix has a comms issue that makes no sense.
It passed all the bench checks, but the second we put it back in the bird, the transmit audio cuts out above 10,000 feet. We've swapped the rack, the tray, and even the antenna coupler. Has anyone in a hot/dry climate run into something like this with a pressure-sensitive fault?
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faith_shah8815d ago
Pressure gremlins are the worst kind. It reminds me of how my old car's power steering would whine only on cold mornings, a problem that vanished at the shop. There's always some hidden variable, like temperature or humidity, that the perfect test bench can't copy. You chase the fix by swapping parts, but the real answer is usually in the weird, specific conditions you can't easily test for.
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marydavis14d ago
Like @faith_shah88 said, these hidden variable faults show up everywhere, from planes to my old fridge that only hummed when it rained.
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gibson.morgan14d ago
Check the pressurization seals on the connector backshells. Seen a Cessna 172 with a similar ghost where the cabin pressure change at altitude would slightly pull a wire bundle away from a pin. On the ground, everything tested fine because the connection was made. Up high, the gap opened just enough to kill the signal. It's a long shot, but pressure does weird things to connectors.
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