Delta Air Lines

SUBJECT: Notice of Proposed Rule Making (NPRM) – A330 FWD and AFT Mount Pylon Bolts REFFERENCE: (A) NPRM Docket No. FAA-2010-0278, Directorate Identifier 2009-NM-255-AD (B) Airbus SB A330-71-3020, dated 10Jun09 (C) Pratt and Whitney Service Bulletin PW4G-100-71-35, dated 14Mar08 (D) Pratt and Whitney Service Bulletin PW4G-100-71-35 Rev 1, dated 04Dec09 (E) EASA AD 2009-0240 dated 05Nov09 The FAA recently issued Ref (A) NPRM which, if adopted, would require a detailed inspection of the part number, serial number and lot number of the forward and aft mount pylon bolts on both engines for all A330 aircraft fitted with Pratt and Whitney engines in accordance with Ref (B) Delta has reviewed Ref (A) NPRM and agrees with the intent of Ref (A), but offers the following comment for your consideration prior to issuance of the AD: Paragraph 2(h) specifically requires operators to identify part number, serial number and lot number against a list of suspect bolt numbers in Ref (C) Service Bulletin. However, since the issuance of Ref (B) and Ref (E), Pratt and Whitney has issued Ref (D) revision which reduces the suspect bolt serial numbers of Lot No. 09 by quantity 1,000. This reduction results in 1,000 bolts that are no longer considered suspect and would lessen the number of bolts required to be removed and destroyed. Therefore, Delta requests that the final rule includes the Ref (D) Service Bulletin as the corresponding source which identifies the suspect bolt number. This action would reduce the amount of required bolt removals and replacements. Should you have any questions or require further information, please contact Project Engineer Sandy Wiese by email at sandra.wiese@delta.com or by telephone at (612) 727-4483.