United Airlines

United Airlines generally agrees with the proposed requirements of NPRM 2011-NM-051-AD. However, paragraph (y) specifies that certain sampling rudders have two repeat ELCH inspections accomplished at 4000-4500 flight cycle (FC) intervals after the sampling inspection. No grace period from AD effective date is provided for the first inspection; some rudders may already exceed these limits. In consideration that rudders were selected randomly for the sampling inspection – that is, they have no unique safety risk compared to non-sampled rudders – UAL proposes an alternative for paragraph (y): 1) Re-start the three-time inspections for trailing-edge ELCH-applicable areas (as if no sampling ELCH inspection has been accomplished). Adopt the same timing limitations as paragraph (s). Credit may be taken for prior accomplishment of any vacuum-loss inspection areas with permanent hole restoration already performed during the sampling inspection.