mary_kelly•1mo agoTop Commenter

The day a D-sub connector nearly grounded a 737 in Des Moines

I was doing a routine check on a 737-800 last August at Des Moines International when the autopilot started dropping out on approach. Turned out a D-sub pin in the flight guidance computer had worked itself loose from vibration. I re-crimped it with a M22520 tool and put a dab of locking compound on the connector before re-seating it. Has anyone else had luck with locking compound on those high-vibration connectors or do you prefer a different fix?

2 comments

2 Comments

viola_butler1mo ago

That M22520 tool is a solid piece of kit. I had a similar issue on a Falcon 900 last year, engine monitoring computer kept spitting out intermittent faults. After chasing wires for two days I found a loose pin in a D-sub that was barely hanging on. I re-crimped it and used a tiny dab of silicone sealant instead of locking compound, just a drop where the wires enter the back of the connector. It held fine through several hundred hours of flight time after that. The key for me was making sure the crimp depth was right before adding anything else.

jesse2901mo ago

Man locking compound is the way to go for sure! I had a similar thing happen on an old Learjet where a connector in the avionics bay kept working loose. I hit it with a dab of the same stuff and it never moved again. Those crimpers are lifesavers too, but nothing beats a little extra insurance on those high-vibe connectors.