RJ Dial

United Airlines (UA) concurs with the contents of the proposed rule and offers the following comments. 1. Boeing has issued Alert Service Bulletin 747-28A2292, Revision 3, dated December 9, 2010. The proposed AD should reference the latest revision of the service bulletin. 2. AD 2008-10-06, Amendment 39-15512 and AD 2008-10-06 R1, Amendment 39-16160 provide the option to incorporate AWL No. 28-AWL-27 into the maintenance program. For Model 747-400, -400D, and -400F series airplanes, incorporating AWL No. 28-AWL-27 into the maintenance program in accordance with paragraph (g) of AD 2008-10-06, Amendment 39-15512; or AD 2008-10-06 R1, Amendment 39-16160; should terminate the action required by paragraph (l) of the proposed AD. 3. Boeing Alert Service Bulletin 747-28A2292, Revision 3, dated December 9, 2010, states that no more work is necessary on the airplane(s) changed in accordance with Revision 1 and Revision 2 of this service bulletin. Actions done before the effective date of the proposed AD in accordance with Boeing Alert Service Bulletin 747-28A2292, Revision 1, dated October 9, 2008; or Boeing Alert Service Bulletin 747-28A2292, Revision 2, dated May 13, 2010; should be acceptable for compliance with corresponding requirements of the proposed AD. 4. AWL No. 28-AWL-27 was introduced in Revision December 2006 R1 of Boeing 747-400 MPD Document, D621U400-9. The proposed AD should credit incorporation of AWL No. 28-AWL-27 done before the effective date of the proposed AD in accordance with Section 9 of the Boeing 747-400 MPD Document, D621U400-9, Revision December 2006 R1; Revision May 2007; Revision October 2007; Revision November 2007; Revision February 2008; Revision March 2008; Revision April 2008; or Revision March 2009; as acceptable for compliance with the requirements of paragraph (l) of the proposed AD.