Shakedown cruise

[dstclair]

My wife and I are planning a long weekend getaway next weekend (Pirep to follow) so I went out to the hangar yesterday evening to check fluids, air pressure, etc. Decided to pull out the 795 and update the databases for the first time as well. No issues with the plane and, after a bit of wrangling with fly.garmin.com, got the 795 updated.

Phase 2 before a long trip is to have a flight around the patch. My wife wanted to try out her new QT Halo headset as well. Simple 45 minute flight planned to ensure the Sting and the headset were in working order. Beautiful day here in Dallas.

First order of business was to put the 795 back into the Air Gizmo, preflight, then fit the headset to my wife. All good.

Fired up the Sting, all systems go. 795 powers up fine and both QT Halo headset are working, quiet and comfortable. Uneventful run-up and off we go.

Upon leaving the traffic area we both heard a periodic clicking sound, like a relay opening and closing. I have a wig-wag light that alternatives the taxi and landing lights (which is just a relay) so I immediately suspected I had turned this on. No such luck.

I cycled each piece of avionics equipment off with no luck. Switched out my wife's headset with our backup as well. Played with the intercom. Pilot isolate removed the noise from me but not my wife. Noise was definitely through the headset but could not isolate.

My wife was getting nervous so we headed home to diagnose on the ground. Spent another 10 minutes on the Tarmac trying everything (except one thing) including pulling breakers one at a time. No luck. Killing all the avionics did work but didn't indicate which device had an issue.

Back in the hangar, the one breaker I did not pull was the GDL-39. It's not a relay so why bother? Pulled the breaker and NO NOISE. This is good and bad news. Really difficult to get to the GDL-39. Decided to see if it was actually working. Tried to pull up weather on the 795, and the information page said 'no device found'. Hmm. Decided to pull the 795 out and check the 1 wire. No issues there.

When I put the 795 back in, I noticed the spring loaded button did not pop up. Push a little harder and it snapped in place. Powered everything up and the noise was gone!

The 795 has a large connector in the middle of the backside of the unit which was not fully mating with the cable. I'm guessing it had a good connection until we took off which is why we didn't notice an issue until airborne. The GDL also gets power from the cable so I'm guessing it was power cycling and since voice goes through the same cable, the noise bled over. Other symptom I should've caught was the Dynon was not receiving tracking info nor were voice warnings coming through.

Goes to show even small adjustments need a test flight.