KLM Fleet Services

KLM received the subject NPRM for replacement or hardness test of all Ballscrew Actuator Clevis Pins for Thrust Reversers installed on CF6-80C2 engines. KLM does not agree with the intent of the NPRM and we have some comments on the action regarding the subject NPRM. Reason KLM believes it?s overregulated to issue an AD, which requires the replacement or a hardness test of all Actuator Clevis Pins installed on the Thrust Reverser, due to the failure of ONE single Clevis Pin in a world wide fleet of over 7.000 CF6-80C2 Thrust Reversers (21.000 Clevis Pins). This was not a failure of the original design clevis pin. If it was an original design failure a world wide fleet inspection would be acceptable, due to same suspected original installations. In this case it was caused by installation of a non approved part of which the origin and lifetime was not detected. By determining the lifetime a proper inspection program could have been issued. Summarizing 1/ KLM feels failure of a single pin does not warrant the issue of an AD. 2/ Failure of an operator or MRO to install specified parts may not result in issuance of an AD for the entire world fleet. 3/ We also believe the investigation should have shown the number of cycles this type of low carbon steel can sustain prior to failure. Based on these figures a repeat inspection could have been issued to monitor the condition of the clevis pins. 4/ Furthermore KLM feels the OEM should issue a service bulletin prescribing inspection procedures and hardnesstest criteria prior to AD-issue. KLM kindly request the FAA to reconsider this rulemaking.