Deutsche Lufthansa AG

Comment for NPRM Docket No. FAA-2009-0293, Directorate Identifier 2008-NM- 221-AD Ladies and gentlemen, please find enclosed a comment for the above mentioned notice of proposed rulemaking: Since the introduction of the B747-200 on Lufthansa fleet, Lufthansa Technik is doing overhaul on the no-back brakes. The no-back brakes are removed every 6 years during D-Check and are overhauled in accordance with the latest Boeing Overhaul Manuals 27-52-41 and 27-52-71. An analysis of 330 shop reports back to the year 1995 did not reveal any failure of the brake system. Neither Lufthansa nor third-party customers of Lufthansa Technik ever experienced a flap blow back event (which is extremely improbable due to the fact that a simultaneous double failure has to be existent). With the above mentioned overhaul and an additional maintenance task (detailed inspection of inboard and outboard flap drive torque tubes and torque tube bearing supports, interval: 18MTH), Lufthansa is significantly reducing if not even excluding the risk of a double failure. Lufthansa has doubts that all criteria for the issuance of an AD are met. There is no comprehensible technical background. Based on the large in-service and overhaul expertise, Lufthansa requests a repetitive (D-Check) shop overhaul (with updated procedures, if necessary) as an alternate method of compliance to the modification in accordance with SB 747-27- 2422 resp. NPRM 2008-NM-221-AD. Lufthansa also urgently requests a compliance time of 8-8-6 years (D1: 8 years, D2: 8 years, D3 and subsequent: 6 years acc. to the latest approved MRB) in order to avoid further impact due to additional downtimes. Best regards J. Hirsch on behalf of Deutsche Lufthansa AG Technical Operation Department FRA OB/M-E