Airworthiness Directive · Amendment 39-17500 · Doors
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model 737-200, -200C, -300, -400, and -500 series airplanes, certificated in any category.
We are superseding airworthiness directive (AD) 2000-06-13 R1, which applied to certain The Boeing Company Model 737-200, -200C, -300, and -400 series airplanes. AD 2000-06-13 R1 required repetitively inspecting for cracking of the corners of the door frame and the cross beams of the aft cargo door, and corrective actions if necessary. AD 2000-06-13 R1 also required modifying the aft cargo door, which terminates the repetitive inspections. This new AD adds airplanes to the applicability, adds inspections and related investigative and corrective actions, revises certain inspection types, and reduces a certain compliance time for modifying the doors. This AD was prompted by reports of cracking in the forward and aft corner frames of the aft cargo door and in the lower cross beam. We are issuing this AD to prevent fatigue cracking of the corners of the door frame and the cross beams of the aft cargo door, which could result in rapid depressurization of the airplane.
Paragraphs (h), (i), (j), (k), and (l) of this AD are restated from AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). These paragraphs apply to Model 737-200 and -200C series airplanes, line numbers 6 through 873 inclusive; and Model 737-200, -200C, -300, and -400 series airplanes, line numbers 874 through 1642 inclusive; equipped with an aft cargo door having Boeing part number (P/N) 65-47952-1 or P/N 65-47952-524, excluding airplanes identified in paragraphs (g)(1) and (g)(2) of this AD.
(1) Those airplanes on which that door has been modified as specified in Boeing Service Bulletin 737-52-1079. Or,
(2) Those airplanes on which the door assembly having P/N 65-47952-524 includes four straps (P/Ns 65-47952-139, 65-47952-140, 65-47952-141, and 65-47952-142) and a thicker lower cross beam web (P/N 65-47952-157).
This paragraph restates the actions required by paragraph (a) of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), with revised service information. For airplanes identified in paragraph (g) of this AD: Within 90 days or 700 flight cycles after December 24, 1998 (the effective date of AD 98-25-06, Amendment 39-10931 (63 FR 67769, December 9, 1998)), whichever occurs later, perform an internal detailed visual inspection to detect cracking of the corners of the door frame and the cross beams of the aft cargo door, in accordance with Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Accomplishment of the modification required by paragraph (l) of this AD constitutes terminating action for the repetitive inspection requirements of this paragraph. Doing the inspections required by paragraph (p) or (s) of this AD terminates the inspections required by this paragraph.
(1) If no cracking is detected, accomplish the requirements of either paragraph (h)(1)(i) or (h)(1)(ii) of this AD.
(i) Repeat the internal visual inspection thereafter at intervals not to exceed 4,500 flight cycles. Or
(ii) Prior to further flight, modify the corners of the door frame and the cross beams of the aft cargo door, in accordance with Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Accomplishment of such modification constitutes terminating action for the repetitive inspection requirements of paragraph (h)(1)(i) of this AD.
(2) If any cracking is detected in the upper or lower cross beams, prior to further flight, modify the cracked beam, in accordance with Part I of the Accomplishment Instructions of Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Part I of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Part II of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Accomplishment of such modification constitutes terminating action for the repetitive inspection requirements of paragraph (h)(1)(i) of this AD for the modified beam.
(3) If any cracking is detected in the forward or aft upper door frame, prior to further flight, repair the frame and modify the corners of the door frame of the aft cargo door, in accordance with Part I of the Accomplishment Instructions of Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Part I of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Part II of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010; except as provided by paragraph (i) of this AD. Accomplishment of such modification constitutes terminating action for the repetitive inspection requirements of paragraph (h)(1)(i) of this AD for the upper door frame.
(4) If any cracking is detected in the forward or aft lower door frame, prior to further flight, replace the damaged frame with a new frame, and modify the corners of the door frame of the aft cargo door, in accordance with Part I of the Accomplishment Instructions of Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Part I of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Part II of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Accomplishment of such modification constitutes terminating action for the repetitive inspection requirements of paragraph (h)(1)(i) of this AD for the lower door frame.
This paragraph restates the requirement of paragraph (b) of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). For actions required by paragraphs (h) and (l) of this AD: Where Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010; specifies that certain repairs are to be accomplished in accordance with instructions received from Boeing, this AD requires that, prior to further flight, such repairs be accomplished in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or using a method approved in accordance with the procedures specified in paragraph (x) of this AD.
This paragraph restates the corrective action required by paragraph (c) of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), with revised service information. If any cracking of the outer chord of the upper or lower cross beams of the aft cargo door is detected during any inspection required by paragraph (h) of this AD, prior to further flight, accomplish the repair specified in paragraph (j)(1), (j)(2), (j)(3), or (j)(4) of this AD. For a repair method to be approved, as required by paragraphs (j)(1), (j)(3), and (j)(4) of this AD, the approval letter must specifically reference this AD.
(1) Repair in accordance with a method approved by the Manager, Seattle ACO.
(2) Repair in accordance with Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010.
(3) Repair in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the FAA to make such findings.
(4) Repair in accordance with a method approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) whom we have authorized to make those findings.
This paragraph restates the actions required by paragraph (d) of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), with revised service information. For airplanes identified in paragraph (g) of this AD: Within 4,500 flight cycles or 1 year after May 9, 2000 (the effective date of AD 2000-06-13, Amendment 39-11654 (65 FR 17583, April 4, 2000), whichever occurs later, perform a high frequency eddy current inspection (HFEC) to detect cracking of the four corners of the door frame of the aft cargo door, using a method approved in accordance with the procedures specified in paragraph (x) of this AD, or in accordance with Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Accomplishment of the modification required by paragraph (l) of this AD constitutes terminating action for the repetitive inspection requirements of this paragraph. Doing the inspections required by paragraph (p) or (s) of this AD terminates the inspections required by this paragraph.
Note 1 to paragraph (k) of this AD: Additional guidance for the inspection can be found in Boeing 737 Nondestructive Test Manual, Part 6, Chapter 51-00-00 (Figure 4 or Figure 23).
(1) If no cracking of the corners of the door frame of the aft cargo door is detected, repeat the HFEC inspections thereafter at intervals not to exceed 4,500 flight cycles until accomplishment of the modification specified in paragraph (l) of this AD.
(2) If any cracking of the corners of the door frame of the aft cargo door is detected, prior to further flight, replace the damaged frame with a new frame, and modify the four corners of the door frame, in accordance with Part II and Part III of the Accomplishment Instructions of Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Part II and Part III of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Part III and Part IV of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Accomplishment of such modification constitutes terminating action for the repetitive inspection requirements of paragraph (k)(1) of this AD for that door frame.
This paragraph restates the action required by paragraph (e) of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), with revised service information. For airplanes identified in paragraph (g) of this AD: Within 4 years or 12,000 flight cycles after August 15, 2001 (the effective date of AD 2000-06-13 R1), whichever occurs later, modify the four corners of the door frame and the cross beams of the aft cargo door, in accordance with Part II of the Accomplishment Instructions of Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Part II of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; or Part III of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Accomplishment of that modification constitutes terminating action for the repetitive inspection requirements of paragraphs (h) and (k) of this AD.
This paragraph restates the method of compliance of Note 3 of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). Accomplishment of the modification required by paragraph (a) of AD 90-06-02, Amendment 39-6489 (55 FR 8372, March 7, 1990), is considered acceptable for compliance with the requirements of paragraph (l) of this AD.
This paragraph restates the credit given for service information specified in Note 4 of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). This paragraph provides credit for the modification of the corners of the door frame and the cross beams of the aft cargo door required by paragraph (l) of this AD, if the modification was accomplished prior to August 15, 2001 (the effective date of AD 2000-06-13 R1), using Boeing Service Bulletin 737-52-1079, dated December 16, 1983; Revision 1, dated December 15, 1988; Revision 2, dated July 20, 1989; Revision 3, dated May 17, 1990; or Revision 4, dated February 21, 1991.
At the applicable time specified in Table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, except as provided by paragraph (u)(1) of this AD: Inspect to determine the configuration of the aft cargo door, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011. A review of airplane maintenance records is acceptable in lieu of this inspection if the configuration of the cargo door can be conclusively determined from that review.
If, during the inspection required by paragraph (o) of this AD, any door is determined to be from any airplane having line numbers 6 through 873 inclusive, and neither the modification nor the repair specified in any service bulletin identified in paragraphs (p)(1) through (p)(7) of this AD has been done as of the effective date of this AD: Do a one-time HFEC and a one-time ultrasonic inspection for cracking of the upper and lower corner frames and the upper and lower cross beams, and do all applicable related investigative and corrective actions, in accordance with Parts II, III, IV, and VI of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010; and, as applicable, the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011; except as provided by paragraphs (u)(2) and (u)(3) of this AD. Do the inspections before the accumulation of 27,000 total flight cycles on the door, or within 4,500 door flight cycles after the effective date of this AD, whichever occurs later (for airplanes on which the door flight cycles are known); or within 4,500 flight cycles after the effective date of this AD (for airplanes on which door flight cycles are not known). Do all applicable related investigative and corrective actions before further flight. If no cracking is found during the initial inspections, before further flight, do the modification in accordance with Part III of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. Doing the inspection specified in this paragraph terminates the inspections required by paragraphs (h) and (k) of this AD.
(1) Boeing Service Bulletin 737-52-1079, dated December 16, 1983.
(2) Boeing Service Bulletin 737-52-1079, Revision 1, dated December 15, 1988.
(3) Boeing Service Bulletin 737-52-1079, Revision 2, dated July 20, 1989.
(4) Boeing Service Bulletin 737-52-1079, Revision 3, dated May 17, 1990.
(5) Boeing Service Bulletin 737-52-1079, Revision 4, dated February 21, 1991.
(6) Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996.
(7) Boeing Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999.
If, during the inspection required by paragraph (o) of this AD, any door is determined to be from any airplane having line numbers 6 through 873 inclusive: Before the accumulation of 27,000 total flight cycles on the door, or within 4,500 door flight cycles after the effective date of this AD, whichever occurs later, (for airplanes on which the door flight cycles are known); or within 4,500 flight cycles after the effective date of this AD (for airplanes on which door flight cycles are not known); inspect the lower corner frames to determine if the door has reinforcement angles, P/N 65C25180-9, -43, -10, -11, or -12, that were installed as specified in any service bulletin identified in paragraphs (q)(1) through (q)(5) of this AD. If any affected reinforcement angle is found, do a one-time general visual inspection for edge margin and do a detailed inspection for cracks; in accordance with Part V of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010.
(1) Boeing Service Bulletin 737-52-1079, dated December 16, 1983.
(2) Boeing Service Bulletin 737-52-1079, Revision 1, dated December 15, 1988.
(3) Boeing Service Bulletin 737-52-1079, Revision 2, dated July 20, 1989.
(4) Boeing Service Bulletin 737-52-1079, Revision 3, dated May 17, 1990.
(5) Boeing Service Bulletin 737-52-1079, Revision 4, dated February 21, 1991.
If, during any inspection required by paragraph (q) of this AD, any crack is found, or if any edge margin does not meet the specification identified in Part V of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010, before further flight, do the actions specified in paragraphs (r)(1), (r)(2), and (r)(3) of this AD.
(1) Replace the corner reinforcement angle, in accordance with Part III of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010.
(2) Do a one-time detailed inspection or HFEC inspection for cracking at the forward and aft ends of cross beam D, in accordance with Part 1 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010; or Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011. If any cracking is found, before further flight, do all applicable repairs in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010; or Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011, except as provided by paragraph (u)(2) of this AD.
(3) Do a one-time detailed inspection or ultrasonic inspection for cracking on the frames, in accordance with Part 2 (detailed inspection) or Part 8 (ultrasonic inspection) of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011. If any cracking is found, before further flight, replace the frame in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010.
If, during the action required by paragraph (o) of this AD, a door is determined to be from an airplane having line numbers 874 and subsequent: At the applicable time specified in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, except as provided by paragraph (u)(1) of this AD, do high frequency and detailed inspections for cracks in the forward and aft ends of cross beam E, and do all applicable related investigative and corrective actions, in accordance with Parts 1, 3, 4, 5, and 6 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; and, as applicable, the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011; except as provided by paragraph (u)(2) of this AD. Do all applicable related investigative and corrective actions at the applicable time specified in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, except as provided by paragraph (u)(1) of this AD. If no cracking is found during the inspections specified in Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, at the applicable time specified in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, except as provided by paragraph (u)(1) of this AD, do the modification in accordance with Parts 5 and 6, as applicable, of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011. Repeat the inspections thereafter at the times specified in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, until the preventative modification or repair is done to both ends of cross beam E in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011. Doing the inspection specified in this paragraph terminates the inspections required by paragraphs (h) and (k) of this AD.
If, during the actions required by paragraph (o) of this AD, a door is determined to be from an airplane having line numbers 874 and subsequent: At the applicable time specified in Tables 3 and 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, except as provided by paragraph (u)(1) of this AD, do a one-time ultrasonic inspection of the frame and a detailed inspection of the reinforcing angle for cracks of the forward and aft ends of cross beam E, and do all applicable related investigative and corrective actions, in accordance with Parts 1, 3, 4, 7, and 8 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; and, as applicable; the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011; except as provided by paragraph (u)(2) of this AD. Do all applicable related investigative and corrective actions before further flight.
The following exceptions apply to this AD.
(1) Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, specifies a compliance time “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010; and Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011, specify to contact Boeing for repair, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (x) of this AD.
(3) Where Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010, specifies to contact Boeing for repair, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (x) of this AD.
(4) This AD does not require accomplishment of the access and restoration procedures identified in the Work Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010; Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010; and Boeing Special Attention Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011.
(1) The supplemental structural inspections specified in Tables 5 and 6 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; and Tables 3 and 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010; and Table 5 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011, are not required by this AD.
(2) The damage tolerance inspections specified in Tables 5 and 6 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; and Tables 3 and 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010; and Table 5 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-52-1154, dated December 17, 2010, as revised by Boeing Special Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 2011; may be used in support of compliance with section 121.1109(c)(2) or 129.109(b)(2) of the Federal Aviation Regulations (14 CFR 121.1109(c)(2) or 14 CFR 129.109(b)(2)). The corresponding actions specified in the Accomplishment Instructions and figures of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; and Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010; are not required by this AD.
