Ole Hesse

The Service Bulletins specified in paragraph (g) of the proposed AD require inspecting the AOA sensors, to determine if the AOA sensors installed are either Conrac/Ametek/Gulton sensors (part number 2566A21, 2566A30 or 2566A40S) or Goodrich/Rosemount sensors. In case the AOA sensors are found to be Conrac/Ametek/Gulton sensors, the Service Bulletins require additional action. In many cases, it will be possible to determine the part number installed on a given aircraft from the aircraft's maintenance documents. The Beoing delivery documents contain a list with, amongst others, the part numbers of the AOA sensors that are installed at aircraft delivery; in case of an AOA sensor being changed/replaced after delivery, this will be recorded in the aircraft's maintenance records; some operators keep databases with the part numbers and serial numbers currently installed on their airplanes. Lufthansa Technik therefor suggests that the text of the AD is changed to open for a review of the maintenance records in lieu of the inspection required by the Service Bulletins. In order to avoid incorrect results of the reviews due to incomplete or unclear maintenance records, this option should be limited to those cases where the part number of the sensors can be determined from that review without any doubt. Lufthansa Technik proposes to add the following text to paragraph (g) of the proposed AD: "A review of aeroplane maintenance records is acceptable in lieu of the inspection required by paragraph (g) of this AD if the part number of the installed AoA sensor can be conclusively identified from that review."