Water and Electronics
Our club had its annual float fly this weekend. One of the pilots was flying a DeHavilland Beaver on floats, and because of the gusty conditions, the plane nosed over and buried the front end in the water. He got into the boat and fished it out, but it had been in the water for several minutes. When he got it back to shore, he shook out the water, dried it out as best he could, and then tried the motor and controls. It seemed to work fine, and all of the control surfaces operated properly. A little later, he was putting in another flight when he suddenly lost control and the plane flew inward, over a number of people and hit a tree. Major damage to the wing and maybe some other stuff.
Later in the day, I did a nose down "landing" in the lake and the plane had to be fished out. Everything inside the Coota was submerged. When I got the plane back to shore, I dumped out the water and then tried the controls. Nothing worked so assumed that I had fried the ESC or worse. After getting it home, I cut the plastic covering off of the ESC and found water inside. I dried the water and then gave it a good treatment with a hair dryer to dry it out completely. I reconnected it, but found that there was still no control to the motor or surfaces but the ESC was beeping, indicating that there was no throttle input from the receiver.
The next thing that I did was to cut the plastic covering off of the Berg receiver and check it out. I found two small droplets of water inside. Drying them off and using the hair dryer resulted in the receiver and the rest of the plane working properly.
The moral of this story is that if you are flying from water and you dunk your plane, don't be lulled into a false sense of security just because everything still works after you drain out the water. I believe that there is a good chance that the receiver in the Beaver had water inside, but its effect did not show up until the model was flown and the water moved around and caused the receiver to stop working. We were fortunate in that no one was hurt by the out-of-control plane. It is much safer to quit flying the plane for the day than to cause an accident or lose your plane to a crash.
Bob