Flew down to Hyannis on Friday afternoon and I was a very unhappy AOA camper. During the 20 min flight, the AOA Pro display became quite dim, and I was seeing numbers on the bottom that were fluctuating between 150 and 200 in level flight. I pulled the breaker and reset and got
E11 and E33 for error messages. I never see these error messages on power up. Later in the flight, the display appeared to be functioning normally again. Back in the hangar, I checked the upper port drain valve and got about a 1/4tsp of water. The 1hr test flight this afternoon showed the AOA to be functioning
normally again. Hard to imagine that small amount of water could be the culprit though. I'm thinking now that I should disconnect the upper/lower
pressure port lines and apply a bit of compressed air to be certain they are free of any moisture.

Angier Ames
N4ZQ