Southwest Airlines

SWA Comments for NPRM 2011-NM-073-AD: Comment #1: NPRM Requirement: Paragraph (s) states that “For airplanes on which no damage is found in the flanges or the Web during any inspection required by paragraph (p) of this AD; and for airplanes on which a repair is done during any corrective action required by (p) of this AD; before further flight, do the inspections specified in paragraphs (s)(1) through (s)(4) of this AD, and do all applicable related investigative and corrective actions, in accordance with paragraphs 3.B.4. and 3.B.5. of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012”. SWA Questions/Comments: SWA is concerned with SB 737-57A1271, paragraph 3.B.5. (Inspection – Group 3 Airplanes – 737-300/400/500) steps d.(4)(5)(6) which calls to use Figure 6 for Corrosion or damage removal from track aft mating surface (common to wing) and to attach holes. Figure 6 has Rework Tables 1 through 5, with Rework Table 5 covering Flap Tracks 65C34809-2, 65C35387-2 and 65C35616-3. On all Tables there are no Minimum Allowable Dimensions for track 65C34809-3 (65C34812-8 Track Assembly). SWA has 65C34812-8 track assemblies (65C34809-3 tracks) installed on aircraft that are effective to the requirements of this NPRM and Boeing SB. SWA Proposed Solutions: SWA requests that Boeing Service Bulletin 737-57A1271, Revision 3, Figure 6 should be revised to add Minimum Allowable Dimensions T1 through T4, W and Maximum Allowable Hole Diameters d1, d2 and d3 for 65C34809-3 track. Comment #2: NPRM Requirement: Paragraph (t) states that, “Within 10,000 flight cycles on the flap track or 48 months, whichever occurs first after accomplishing the inspections required by paragraph (p) of this AD: Do an overhaul of the flap track, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012”. SWA Questions/Comments: SWA is concerned with SB