93-05-05 BOEING: Amendment 39-8510. Docket 92-NM-27-AD. Supersedes AD 88-13- 51 R1, Amendment 39-6088. \n\n\tApplicability: Model 737-300, 737-400, and 737-500 series airplanes; equipped with CFM International CFM56-3 series engines; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent engine flameout during airplane descent in moderate to severe inclement weather conditions, accomplish the following: \n\n\t(a)\tFor Model 737-300 series airplanes: Within 10 days after December 30, 1988 (the effective date of AD 88-13-51 R1, Amendment 39-6088), accomplish the procedures specified in paragraphs (a)(1), (a)(2), and (a)(3) of this AD: \n\n\t\t(1)\tRevise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) by adding the following instructions. This may be accomplished by inserting a copy of this AD into the AFM. (Where appropriate, remove the previous inserted copy of AD 88-13-51 from the AFM.) \n\n\t"OPERATION IN MODERATE TO HEAVY RAIN, HAIL, OR SLEET: \n\n\tWhen operating in or in the vicinity of (near) moderate to heavy rain, hail, or sleet, \t\taccomplish the following: \n\n\t\t\t(i)\tEngine start switches.....FLIGHT \n\n\t\t\t(ii)\tMinimum Engine N1.....45% \n\n\t\t\t(iii)\tAuto-throttle.....OFF \n\n\t\t\tNOTE: Operation in or in the vicinity of (near) moderate to heavy rain, \t\t\thail, or sleet is to be assumed if indicated by any of the following \t\t\t\tsources: weather radar, reports, or observations. \n\n\tOPERATING IN THUNDERSTORM ACTIVITY: \n\t\t\tCautionary Note \n\n\tFlight operation should be conducted so that operation within 5 miles of thunderstorm \tactivity is avoided." \n\n\t\t(2)\tFor operations in known or forecast rain, hail, or sleet, notwithstanding the Minimum Equipment List (MEL), the weather radar must be operable for dispatch. \n\n\t\t(3)\tInstall a placard (red base, white lettering) on the instrument panel in clear view of the flight crew and in close proximity of the engines' N1 indication gauges, that reads as follows: \n\n\t\t\t"Maintain At Least 45% N1 When Operating In Or Near Moderate To \t\t\tHeavy Rain, Hail, Or Sleet." \n\n\t(b)\tFor Model 737-300 series airplanes: Within the next 48 months after the effective date of this AD, accomplish the engine modification described in Boeing Service Bulletin 737-77-1031, Revision 1, dated May 14, 1992. Accomplishment of this modification constitutes terminating action for the requirements of paragraph (a) of this AD; the AFM revision, the MEL configuration requirements, and the N1 placard may be removed at that time. \n\n\t(c)\tFor Model 737-400 and 737-500 series airplanes: Within the next 48 months after the effective date of this AD, accomplish the engine modification described in Boeing Service Bulletin 737-77-1031, Revision 1, dated May 14, 1992. Upon accomplishment of this modification, the AFM limitations pertaining to "OPERATION IN MODERATE TO HEAVY RAIN, HAIL, OR SLEET" may be removed, as well as the related flightcompartment instrument panel placard, related MEL configuration requirements, and any related 45% N1 idle indication/control limitations. \n\n\t(d)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 1: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\tNOTE 2: Alternative methods of compliance previously granted for Amendment 39- 6088, AD 88-13-51 R1, continue to be considered as acceptable alternative methods of compliance for paragraph (a) of this amendment. \n\n\t(e)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(f)\tThe modification shall be done in accordance with Boeing Service Bulletin 737- 77-1031, Revision 1, dated May 14, 1992. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(g)\tThis amendment becomes effective on April 29, 1993.