FredG Posted January 8, 2017 Report Share Posted January 8, 2017 2006 CTsw, experimental registration. About 900 hrs TTAF. Lots of time in the pattern, with about 2700 landings. About a month ago, the plane developed an intermittent flap control failure. Specifically, when the flaps switch was rotated to extend the flaps, nothing happened. This typically happen when going from 0 to 15 degrees and from 15 to 30 degrees. It could be resolved by quickly switching to retract the flaps (which worked every time) and then back to extend the flaps. It never happened on the ground and it didn't happen early in a flight. It also didn't seem to affect the operations manual side of the switch (up or down). I checked all connections and none appeared to be poor. Based on prior reports of problems with relay board (the board on the firewall), I put my hand on the board and operated the flaps (on the ground). I could feel the relays operating, but, with only light finger pressure on the board, I could stop the flaps from operating. Releasing the pressure and the flaps would run. The stoppage occurred both on extension and retraction of the flaps. I removed the relay board. Removing the board is not fun. First, the two screws holding the board in place were screwed into rivnuts in the firewall. FD (I believe) used a thread locker on the screws and one of the rivnuts spun in place. In addition, the seven connectors on the board are held in place with very secure screw terminals. But, FD (I believe) put a sealer on the screw heads that had to be removed before the connectors could be removed (the sealer fully loaded the slots in the screw terminals). All of this was done with the board in place against the firewall. Once the board came out I could see on the back of the board that one of the soldered connections had failed. See attached photo. I cleaned the lacquer from the failed connection and re-soldered it. Note that it is important to not bridge the solder to a nearby circuit board conductor. I then applied paint to the newly soldered connection and re-installed the board. It worked on the ground, but it worked on the ground previously. A test flight yesterday showed no in-flight failures after five landings (and some air work). I will test again today. This problem has been reported by others on this forum. Still, given this failure, I thought it might be worth mentioning again. Fred Link to comment Share on other sites More sharing options...
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