Jim Bender

These comments are submitted on behalf of Comair, Inc Comments pertain to Paragraph (f)(2). The NPRM references AMM Task 05-51-27-210-810, Revision 28, dated January 20, 2009. For the CL-600-2C10, pre SB 670BA-78-008, the current page revisions are as follows: 601 and 602 are Revision 29, dated Dec 20/2009; pages 603 through 608 are Revision 30, dated Aug 20/2009. For the CL-600-2D24, pre SB 670BA-78-008, the current page revisions are as follows: 609 and 610 are Revision 29, dated Dec 20/2009, pages 611 through 616 are Revision 30, dated Aug 20/2009. The request is for the final rule to reference these newer revisions, or the latest revision, instead of Revision 28. Additionally, only part-3 of this AMM task should be required by the final rule. Part-1 and part-2 do not pertain to the subject of the unsafe condition addressed by this proposed AD and should not be mandated through the AD process. Paragraph (f)(2) needs to define what is considered a “high-energy stop (HES) or rejected take-off (RTO)”. A rejected take-off may occur at any speed and not require any braking or deployment of the thrust reversers. In revision 30 to AMM task 05-51-27-210-807, for both the CL-600-2C10 and -2D24 airplanes pre SB670BA-78-008, Bombardier has defined when part-3, examination of the joint extrusion of the transcowl assemblies, need to be inspected: - If a RTO occurs and thrust reversers are deployed above 68% N1. - If during a HES the thrust reversers are deployed above 68% N1. The final rule should include this definition and not mandate inspections if the RTO/HES occur outside these parameters.