Thursday, April 14, 2011

2011 Annual Inspection (v)

Mike the IA had found a problem with the elevator trim not functioning through its full travel. The trim tab is supposed to deflect 15º in the nose-up direction and it was only reaching 5º. Yesterday morning he told me he'd get into it to diagnose the cause. On investigation, he found that the trim actuator would only retract partially and as a result would not go all the way to the nose-up stop. He thought at first that it might be bent, a genuinely unpleasant prospect since the cost of a new actuator is about $2,000. So Mike pulled the actuator drive screw to confirm why it was bad and to see if there was anything to be done about it.

Not to keep you in suspense, Mike found that the shaft of the actuator was rusted (left) which kept the actuator from turning in the housing.

Mike was able to clean off the rust and reassembled everything. The trim control now functions as it's supposed to and I'm assured that it should be good for a lot more time. All this at the cost of 3 or 4 of Mike's hours. Compared to the alternative, that's a heck of a bargain!

In other news, it looks definite that we're going to install the Pointer 121.5 MHz ELT (discussed yesterday). The bracket modification is estimated to be a 2 to 3 hour job. Another bargain, compared with the alternative of installing a 406 MHz unit.

Unfortunately, as a result of the late start and the time consumed by the ELT issue and the trim actuator issue, it looks like N631S will not be ready for the weekend. I'd rather have things done right than done quick, of course, but it'll be one more weekend on the train.

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