Anthony Chen

United Airlines would like to submit its comments for the Notice of Proposed Rulemaking (NPRM) number 2012-NM-144-AD, and thanks you for the opportunity to do so. Subject: Paragraph (m), (o), and (p), regarding Corrective Actions for Damage: Comment: Due to the threshold and repeat interval of 500 Flight Cycles, United is concerned that this inspection will take place at mainly aircraft Line Maintenance Stations, with significant exposure to possible damage condition(s) that require correction BEFORE FURTHER FLIGHT. The corrective actions specified in Service Bulletins 25-1557 & 52-1215, which certain damage conditions require correction before further flight, also carry a required manpower of appoximately 57 MHRS, which would lead to lengthy Out-Of-Service time and costs to the airline. Additionally, typical aircraft Line Stations may not have the resources, materials, and equipment to perform this type of modification, repair, and gaining of access. Proposal: As a proposed alternative, United recommend that Paragraphs (m) and (o) and (p) be amended to state: "If any damage / cracking is found during any inspection required by Paragraph (l), (n), or (p) of this AD....: a) "Within one deferral flight cycle, or the applicable time given in Paragraph E. (2) "Accomplish Timescale" of subject Service Bulletin, whichever is later, accomplish the applicable corrective actions in accordance with subject Bulletin..." b) "Within the later of 50 Flight Cycles and the applicable time given in Paragraph E. (2) "Accomplish Timescale" of subject Service Bulletin, accomplish the applicable corrective actions in accordance with subject Bulletin..." Benefits: Option a) would give operators a chance to fly a ferry flight to a more equipped resourced Base Maintenance Station. Option b) would give operators an option to create a short-term deferred item to plan for its accomplishment by creating a formal maintenance task with planned allocated resources.