Following the instructions on an AD related item such as the install instructions for the rudder stop kit, everyone needs to remember the following "NO Deviations or Substitutions Allowed".
If you and your mechanic remember that simple little phrase, it will go a long ways in keeping you out of trouble with the Feds. This is drilled into us at work, and is printed on the header of every page of any AD related paperwork.
If the instructions say to use an AN960-10L washer (1/32" thick steel washer, for 3/16" bolt or screw) don't even think about digging in the junk box and finding an using a AN960PD10L washer (aluminum version of the same washer). Same goes with any other piece of hardware. If a certain piece of hardware is called out, use that exact item, and nothing else. If it doesn't work as specified, its time to stop and call Cessna (or whoever the AD is against) and the responsible FAA office.
At work, our engineering department frequently puts in request for an AMOC (Alternate Method Of Compliance) for an AD either due to an airplane which was optioned or spec'ed out differently than the AD is written for, or the airplane has had a repair of some sort that makes compliance with the AD as written impossible. After several fiasco's and debacles, we have finally figured it out........ exactly as written, no exceptions.
In the case of this rudder stop AD, a real anal and enterprising mechanic might come up with a more accurate method of measuring the rudder travel. He might get it exactly 23° as called out, but if he didn't use the method specified in the maintenance manual, he did it wrong! Its easier to do it as specified than to try to lie your way out of it later on.
Charles
