What will I be facing if I want to get an S-Tec 30 (STec-30) autopilot put in my plane?
Larry Stetz:
Now that we have the plane back with a new S-tec 30, maybe I can help others that might be contemplating an autopilot installation. I have a 1966 Super III, serial number MA57. It is an A23/24, and S-tec holds an STC for this model. Last week the avionics shop doing the install informed us that we would have to comply with a Beechcraft Service Letter, Volume XX, No.11 issued in November of 1967. After checking the archives here and at BAC to no avail, I posted a question here to Musketeer mail and received some useful info, but no copy of the Service Letter. My partner called Raytheon and they were kind enough to dig it out of their archives.
A couple of other issues also came to light; the pitch servo bracket supplied by S-tec did not fit our aircraft, and S-tec claimed that we needed to comply with Beechcraft S.B. NO.0253-151. Researching the Service Letter, Volume XX we discovered that this Letter applies only to Musketeers prior to Serials M-963 and MA-28. Our plane was manufactured with the latest rudder-aileron improvement called for in this Service Letter. Even with this
improvement, the servo for the rudder-aileron cable had to be moved down stream on the cable; it could not be installed where S-tec originally wanted it. The pitch servo bracket problem was solved by the engineering department at S-tec; they made the bracket 2 inches longer. Now for the final problem, S.B. No. 0253-151; it
was decided that this bulletin only applies when the aileron centering cable has to be replaced, as it is a recommended improvement.
Now for the fun part. We flew the plane with the new toy, and what a toy it is!!! The S-tec 30 is an amazing piece of avionics.