79-24-01 R3 MCDONNELL DOUGLAS: Amendment 39-3618 as amended by Amendment 39-3741 and 39-3841 is further amended by Amendment 39-4191. Applies to McDonnell Douglas Model DC-9 series airplanes, certificated in all categories, equipped with the non-ventral door aft pressure bulkhead P/N 5910163, and with more than 10,000 landings. \n\n\tCompliance required as indicated. \n\n\tTo detect fatigue cracks and prevent failure of the aft pressure bulkhead, accomplish the following: \n\n\t(a)\tFor aircraft not previously modified or repaired in accordance with McDonnell Douglas DC-9 Service Bulletin 53-127 dated May 25, 1976, accomplish the following: \n\n\t\t(1)\tWithin 10 landings after the effective date of this AD, unless already accomplished in accordance with telegraphic AD T79WE13 dated September 18, 1979 or telegraphic AD T79WE15 dated September 28, 1979, conduct an initial visual inspection per Step 1, Figure 1, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979. The visual inspection shall encompass the entire periphery of the emergency exit doorjamb structure. \n\n\t\t(2)\tWithin 100 landings after the effective date of this AD, unless already accomplished in accordance with telegraphic AD T79WE15 dated September 28, 1979, conduct both visual and X-ray inspections per Steps 3 through 10, Figure 1, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979. The visual portion of the inspection shall encompass the entire periphery of the doorjamb structure. \n\n\t\t(3)\tWithin 250 landings of the inspection required by paragraph (a)(2) of this AD and thereafter at intervals not to exceed 250 landings, conduct a visual inspection per Step 1, Figure 1, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979. The visual inspection shall encompass the entire periphery of the emergency exit doorjamb structure. \n\n\t\t(4)\tWithin 1,000 landings from the inspection required by paragraph (a)(2) and thereafter at intervals not to exceed 1,000 landings, conduct X-ray inspections per Steps 8 through 10 and a visual inspection per Step 1, Figure 1, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979. The visual inspection shall encompass the entire periphery of the emergency exit doorjamb structure. \n\n\t(b)\tFor aircraft previously modified or repaired per McDonnell Douglas DC-9 Service Bulletin 53-127 dated May 25, 1976, accomplish the following: \n\n\t\t(1)\tWithin 100 landings after the effective date of this AD, unless already accomplished subsequent to September 25, 1979, conduct X-ray inspections per Steps 8 through 10, Figure 1, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979, and a visual inspection of the entire periphery of the emergency exit doorjamb structure. \n\n\t\t(2)\tWithin 2,000 landings after inspection per paragraph (b)(1) of this AD and thereafter at intervals not to exceed 2,000 landings, conduct X-ray inspections of the jamb structure per Steps 8 through 10, Figure 1, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979, and a visual inspection of the entire periphery of the emergency exit doorjamb structure. \n\n\t(c)\tIf cracks are found during any of the inspections required by this AD, repair before further flight in accordance with the following: \n\n\t\t(1)\tFor cracks which are limited to the emergency exit doorjamb, repair as shown for Condition 2, Figure 2, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979. \n\n\t\t(2)\tFor cracks which extend through the emergency exit doorjamb and into the pressure bulkhead web, repair as shown for Condition 3, Figure 3, of McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979. \n\n\t\t(3)\tFor cracks for which no repair is prescribed in McDonnell Douglas DC-9 Alert Service Bulletin A53-127, Revision 1, dated September 26, 1979, repair in accordance with data approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t(d)\tWithin 24 hours after the initial inspections per paragraph (a)(2) and paragraph (b)(1), report the results of the initial inspections by Telex to the Chief, Aircraft Engineering Division, FAA Western Region. Include in the reporting information the date and condition of modification or repair per DC-9 Service Bulletin 53-127 or A53-127, McDonnell Douglas fuselage number, factory serial number, and registration number. \n\n\t(e)\tWithin the next 500 landings after April 14, 1980 or at the next inspection required by paragraph (a)(4) or (b)(2), whichever occurs first, visually inspect the auxiliary emergency exit door jamb for repairs in accordance with paragraph (2)(C) of McDonnell Douglas DC-9 Alert Service Bulletin A53-146, dated March 14, 1980 (hereinafter referred to as SB A53-146). Repairs not in accordance withSB A53-146 are to be modified as follows: \n\n\t\t(1)\tFor repairs to cracks which extend radially outboard, prior to further flight the repair must conform to the configuration defined by paragraph (2)(C) Condition III Type 3 of SB A53-146. \n\n\t\t(2)\tFor repairs to cracks which extend radially inboard, within the next 500 landings the repair must conform to the configuration defined by paragraph (2)(C) Condition III Type 2 of SB A53-146. \n\n\t\t(3)\tFor repairs to circumferentially oriented cracks, within the next 1,000 landings, the repair must conform to the configuration defined by paragraph (2)(C) Condition III Type 1 of SB A53-146. \n\n\t(f)\tIf a new replacement door jamb, P/N 5910163-9 or -255 is installed, within 10,000 landings after installation of the new door jamb, and thereafter at intervals not to exceed 2,000 landings, inspect the door jamb in accordance with paragraph (b)(2). \n\n\t(g)\tAlternative inspections, modifications or other actions which provide an equivalent level of safety may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t(h)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplanes unpressurized to a base where the inspections or crack repair can be performed. \n\n\t(i)\tFor the purposes of complying with this AD, subject to acceptance by the assigned FAA maintenance inspector, the number of landings may be determined by dividing each airplane's hours' time in service by the operator's fleet average time from takeoff to landing for the DC-9 airplane. \n\n\t(j)\tThe inspections and modifications required by this AD need not be accomplished if, after the effective date of this AD, the aircraft is operated without cabin pressurization and a placard is installed in the cockpit, in full view of the pilots, stating: \n\n\t\t"Operation with Cabin Pressurization is Prohibited." \n\n\t(k)\tThe installation of a J060116-11 Jamb Assembly in accordance with McDonnell DouglasDC-9 Service Bulletin 53-145, Revision No. 1, dated January 29, 1981, or later revisions approved by the Chief, Los Angeles Area Aircraft Certification Office, Northwest Region, constitutes terminating action for the repetitive inspections required by paragraphs (a)(3), (a)(4) and (b)(2) of this AD. \n\n\tThe manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). \n\n\tAll persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director, Publications and Training, C1-750 (54-60). \n\n\tThese documents also may be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108 or Los Angeles Area Aircraft Certification Office, 4344 Donald Douglas Drive, Long Beach, California 90808. \n\n\tAmendment 39-3618 became effective December 24, 1979 and was effective upon receipt for all recipients of telegraphic AD T79WE13 dated September 18, 1979 and telegraphic AD T79WE15 dated September 28, 1979. \n\n\tAmendment 39-3741 became effective April 14, 1980. \n\n\tAmendment 39-3841 became effective July 17, 1980. \n\n\tThis Amendment 39-4191 becomes effective August 27, 1981.