American Airlines

American Airlines understands the basis for this modification and would like to provide the following comments. The NPRM recognizes revision 1 of service bulletin 737-31A1332 as the governing document for the AD. American Airlines believes revision 2 should be utilized. Revision 2 corrects errors in the bulletin, has been completed by Boeing, and is currently under FAA review. Utilizing the newer revision will result in a better product and significantly reduce the number of AMOC approvals needed by all operators. An evaluation of service bulletin 737-31A1332 by the American Airlines Production Department, and accomplishment of the bulletin on a prototype aircraft, resulted in a man-hour requirement approximately 2.5 times greater than the 64 hours shown in the NPRM. A better estimate for completing the entire modification would be 140 man-hours. American Airlines has started our program of accomplishment of service bulletin 737-31A1332 but adoption of the 36 month accomplishment schedule will result in 6 aircraft than cannot be completed in our normal heavy maintenance schedule. These aircraft will require a higher cost special visit. The mitigating flight manual procedures will remain in place until all aircraft are modified.