Grounded a Hawker 800 over a loose connector I could have caught

I was doing a routine check on a Hawker 800 out of Van Nuys last month. Everything looked fine on the initial test. But when the pilot fired up the avionics, the GPS kept dropping. I spent three hours chasing a ghost in the wiring. Finally found it. A pin on the back of the NAV unit had worked itself loose halfway out. Must have been from a previous install. Took me two minutes to reseat it. Has anyone else had a pin walk out on you like that on a midsize jet?

2 comments

2 Comments

barbara_kim15d ago

Wait, was it a specific pin on the backplane or just one of the D-sub pins? I had something similar happen with a King Air B200 where one of the pins on the NAV receiver's Molex connector just... came loose. It was grounding out against the shell. I ended up putting a tiny dab of nail polish on the pin after reseating it, same trick we used on old Learjets to keep them from walking out again. Probably not FAA approved but it's held for like 2 years now. Definitely a 2 minute fix but the three hours before that are brutal.

the_patricia15d ago

I mean, I get why you'd do the nail polish thing on an old Lear, but on a Hawker 800 that's still flying charter out of Van Nuys, that's a liability I wouldn't touch. The pin walking out on the back of the NAV unit is a known issue on these birds, but the fix should be a proper lockwire or a new connector housing, not something that could flake off or get missed by the next guy. @barbara_kim I know it's held for two years, but one bad inspection or a hot day could turn that nail polish into a sticky mess that doesn't actually prevent the pin from backing out again. I spent three hours digging in the panel too, and honestly, I'd rather eat that time than risk an IFR departure with a GPS that might quit at the wrong moment. The right thing is to replace the D-sub shell or use a proper locking retainer, even if it means a service bulletin or a parts order.