Lufthansa Technik

LHT CF6-80 Thrust Reverser engineering department like to add following comments in regards to docket FAA-2009-0018. Refer to “initial compliance period” a change from 500 Flight Cycles after the issue date of the service bulletin into until next C-check, at least a minimum of 500 Flight Cycles, since required inspections as well as possible rod end; adjustable 3/8” rod end actuator and clevis fastener replacements, resp. increases man-hours and maintenance facility demand. Clevis Pin inspection states a minimum serviceable diameter of .3705” (9.411mm), a typical vernier calibre, (standard mechanic tool) couldn’t measure up to this small diameter, even a digital vernier calibre could measure up to 1/100 mm. In case of any findings during inspection of the clevis fasteners, a replacement of the fasteners according CMM 78-32-31/32 Repair 022 is required. Repair 022 introduces -8 HL tension fasteners. While performing the repair, workshop experience shows insufficient distance between bore and clevis radii for tension head fastener installation. An introduction -6 of shear head oversize fasteners, like HL140-6 or HL62-6 shall be conducted to solve the original Jo Bolt looseness and fastener head interference. Sincerely, Mario Wodniok Product Engineer