1. For Model 747-400 series aeroplanes, as listed in Boeing Alert Service Bulletin 747-27A2348, Revision 1, dated January 26, 1995, modify the hydraulic tubing of the right inboard elevator PCP in accordance with Boeing Alert Service Bulletin 747-27A2348, Revision 1, dated January 26, 1995.
2. For all applicable aeroplanes, modify the left and right servo assemblies of the inboard elevator PCP, in accordance with Parker Service Bulletin 327400-27-171, Revision 1, dated April 14, 1995, or Parker Service Bulletin 93600-27-173 dated May 17, 1995 as applicable.