What was found
WHEN ATTEMPTING TO TRANSITION FROM CRUISE TO DESCENT, THE WIDE-OPEN THROTTLE WAS UNMOVABLE. THIS WAS DUE TO THE FACT THE THROTTLE LEVER WITH ITS FEMALE 45º X 1/16" LONG X 0.015" HIGH SPLINE WAS ALLOWED TO SEPARATE FROM ITS MALE COUNTERPART ON THE THROTTLE SHAFT BECAUSE THE SINGLE SPECIAL LOCKNUT LOOSENED AND BACKED OFF. THERE IS NO WAY TO SAFETY WIRE A NUT IN THIS APPLICATION, AND A CASTLENUT WITH COTTER PIN IS NOT APPLICABLE DUE TO THE SMALLNESS OF THE THROTTLE SHAFT TO ACCEPT A DRILLED HOLE. CRITICAL SERVICE BULLETIN CSB08-3C REQUIRES THIS NUT TO BE TORQUED TO 100 IN. THIS IS NOT NEARLY ENOUGH. IT SHOULD BE TORQUED TO AT LEAST 165 IN#. THEN A PAL NUT SHOULD BE INSTALLED AGAINST THE LOCKNUT AND TORQUE PUTTY APPLIED.