AD 2013-09-10

We are superseding an existing airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD currently requires repetitive inspections to detect cracking of the lower corners of the door frame and cross beam of the forward cargo door, and corrective actions if necessary. That AD also requires eventual modification of the outboard radius of the lower corners of the door frame and reinforcement of the cross beam of the forward cargo door, which terminates the existing repetitive inspections. This new AD revises the compliance times for the preventive modification; adds certain inspections for cracks in the number 5 cross beam of the forward cargo door; and adds inspections of the number 4 cross beam if cracks are found in the number 5 cross beam, and corrective actions if necessary. For certain airplanes, this \n\n((Page 31390)) \n\nnew AD also adds a one-time inspection for airplanes previously modified or repaired, and a one-time inspection of the reinforcement angle for excessive shimming or fastener pull-up, and corrective actions if necessary. This AD was prompted by additional reports of fatigue cracking in the radius of the lower frames and in the lower number 5 cross beam of the forward cargo door. We are issuing this AD to prevent fatigue cracking of the lower corners of the door frame and number 5 cross beam of the forward cargo door, which could result in rapid depressurization of the airplane.

Final rule.

Adoption of the Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\n((Page 31392)) \n\n\n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by removing airworthiness directive (AD) 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), and adding the following new AD: \n\n2013-09-10 The Boeing Company: Amendment 39-17452; Docket No. FAA- 2012-0855; Directorate Identifier 2011-NM-136-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective June 28, 2013. \n\n(b) Affected ADs \n\n\n\tThis AD supersedes AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). \n\n(c) Applicability \n\n\n\t(1) This AD applies to all The Boeing Company Model 737-100, - 200, -200C, -300, -400, and -500 series airplanes, certificated in anycategory. \n\t(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/regulatory_and_guidance_library/rgstc.nsf/0/2C6E3DBDDD36F91C862576A4005D64E2?OpenDocument&Highlight=st01219se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE is installed, a ''change in product'' alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17. \n\n(d) Subject \n\n\n\tJoint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 52, Doors. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by additional reports of fatigue cracking in the radius of the lower frames and in the lower number 5 cross beam of the forward cargo door. We are issuing this AD to prevent fatigue cracking of the lower corners of the door frame and number 5 cross beam of the forward cargo door, which could result in rapid depressurization of the airplane. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Retained High Frequency Eddy Current (HFEC) Initial/Repetitive Inspections \n\n\n\tThis paragraph restates the requirements of paragraph (a) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), with revised service information. Within 1 year or 4,500 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later, perform an HFEC inspection to detect cracking of the lower corners (forward and aft) of the door frame of the forward cargo door, in accordance with Figure 4 or Figure 23, of Section 51- 00-00, of Part 6, of Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, dated August 5, 1997, as applicable; or Procedure 4 or Procedure 23, of Section 51-00-00, of Part 6, of Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, Revision 108, dated November 15, 2012; as applicable. \n\n\n\tNote 1 to paragraphs (g), (h),(i), and (j) of this AD: Accomplishment of Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994, does not supersede the requirements of AD 90- 06-02, Amendment 39-6489 (55 FR 8372, March 7, 1990). \n\n\n\t(1) If no cracking is detected, repeat the HFEC inspection thereafter at intervals not to exceed 4,500 flight cycles, until the requirements of paragraph (i) of this AD have been accomplished. \n\t(2) If any cracking is detected during any inspection required by paragraph (g) of this AD, prior to further flight, accomplish the requirements of paragraphs (g)(2)(i) and (g)(2)(ii) of this AD, which constitute terminating action for the repetitive inspections required by paragraph (g)(1) of this AD. \n\t(i) Accomplish the requirements of paragraph (g)(2)(i)(A) or (g)(2)(i)(B) of this AD, and install a cross beam repair and reinforcement modification of the cross beam, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. \n\t(A) Repair thedoor frame of the forward cargo door in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), Transport Airplane Directorate, FAA; or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make such findings. For a repair or modification method to be approved by the Manager, Seattle ACO, as required by this paragraph, and paragraphs (g)(2)(ii), (h)(2), (h)(3)(ii), and (i)(2) of this AD, the Manager's approval letter must specifically reference this AD. \n\t(B) Replace the door frame of the forward cargo door with a new door frame, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. \n\t(ii) Modify the repaired or replaced door frame of the forward cargo door, in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings. \n\n(h) Retained Initial Detailed Inspection and Repetitive Inspections \n\n\n\tThis paragraph restates the requirements of paragraph (b) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). Within 1 year or 4,500 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later, perform a detailed inspection to detect cracking of the cross beam (i.e., upper and lower chord and web sections) of the forward cargo door, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. For the purposes of this AD, a detailed inspection is: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required. \n\t(1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 4,500 flight cycles until the requirements of paragraph (i) of this AD have been accomplished. \n\t(2) If any cracking is detected on the lower chord section of the cross beam during any inspection required by paragraph (h) of this AD, prior to further flight, repair in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings. \n\t(3) If any cracking is detected on any area excluding the lower chord section of the cross beam (i.e., upper chord and web section) during any inspection required by paragraph (h) of this AD, prior tofurther flight, accomplish the requirements of paragraph (h)(3)(i) or (h)(3)(ii) of this AD, as applicable, which constitutes terminating action for the repetitive inspections required by paragraph (h)(1) of this AD. \n\t(i) For airplanes with line numbers 1 through 1231 inclusive: Install a cross beam repair and preventative modification of the outboard radius of the lower corners (forward and aft) of the door frame, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. \n\t(ii) For airplanes with line numbers 1232 and subsequent: Install a cross beam repair and preventative modification of the outboard radius of the lower corners (forward and aft) of the door frame, in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings. \n\n(i) RetainedTerminating Action \n\n\n\tThis paragraph restates the requirements of paragraph (c) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), with revised service information. Within 4 years or 12,000 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later: Install the preventative modification of the outboard radius of the lower corners (forward and aft) of the door frame and the reinforcement modification of the cross beam of the forward cargo door, in accordance with paragraph (i)(1) or (i)(2) of this AD, as applicable. Accomplishment of paragraph (i)(1) or (i)(2) of this AD, as applicable, constitutes terminating action for the repetitive inspections required by paragraphs (g)(1) and (h)(1) of this AD. \n\n((Page 31393)) \n\n\n\t(1) For airplanes with line numbers 1 through 1231 inclusive: Accomplish the preventative modification and the reinforcement modification, in accordance with Boeing Service Bulletin 737-52- 1100, Revision 2,dated March 31, 1994. \n\t(2) For airplanes with line numbers 1232 and subsequent: Accomplish the preventative modification and the reinforcement modification, in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings; or in accordance with Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011. As of the effective date of this AD, use only Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, to accomplish the modifications required by this paragraph. \n\n(j) Retained Action for Airplanes on Which Modifications Were Accomplished Previously \n\n\n\tThis paragraph restates the requirements of paragraph (d) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). For all airplanes on which modifications of the forward lower corner of the door frame and the cross beam of the forward cargo door were accomplished as specified in Boeing Service Bulletin 737-52-1100, dated August 25, 1988, or Revision 1, dated July 20, 1989; or in accordance with the requirements of AD 90-06-02, Amendment 39-6489 (55 FR 8372, March 7, 1990): Within 4 years or 12,000 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later, install the reinforcement modification of the aft corner of the door frame of the forward cargo door, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. Accomplishment of such modification constitutes terminating action for the repetitive inspections required by paragraphs (g)(1) and (h)(1) of this AD. \n\n(k) New Inspections and Corrective Actions \n\n\n\tExcept as provided by paragraphs (m)(1) and (m)(2) of this AD: At the applicable time specified in paragraph 1.E, ''Compliance,'' of Boeing Alert Service Bulletin 737-52A1100,Revision 5, dated February 14, 2011, do the inspections required by paragraphs (k)(1) and (k)(2) of this AD, as applicable. Do all applicable related investigative and corrective actions before further flight, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011; except as required by paragraph (m)(3) of this AD. Accomplishment of the inspections required by paragraph (k) of this AD terminates the requirements of the repetitive inspections required by paragraphs (g)(1) and (h)(1) of this AD. If any cracking is found in the number 4 cross beam, before further flight, repair in accordance with Boeing Special Attention Service Bulletin 737-52-1149, dated December 11, 2003. \n\n\n\tNote 2 to paragraph (k) of this AD: Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, refers to Boeing Special Attention Service Bulletin 737-52-1149, dated December 11, 2003, as an additional source ofguidance for the inspection for cracks of the number 4 cross beam. \n\n\n\t(1) For airplanes identified in Tables 1 and 2 of paragraph 1.E, ''Compliance,'' of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011: Do a one-time HFEC inspection of the applicable location for cracks, in accordance with the Work Instructions, Part I, of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011. \n\t(2) For airplanes identified in Table 3 of paragraph 1.E, ''Compliance,'' of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011: Do a one-time general visual inspection of the reinforcement angle for excessive shimming or fastener pull-up, in accordance with the Work Instructions, Part III, of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011. \n\n(l) No Supplemental Structural Inspections Required by This AD \n\n\n\t(1) The supplemental structural inspections specified in Table 4 of paragraph 1.E., ''Compliance,'' and Part 5 of the Accomplishment Instructions, of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, are not required by this AD. \n\t(2) The supplemental structural inspections specified in Table 4 of paragraph 1.E., ''Compliance,'' of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 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 of Boeing Alert Service Bulletin 737- 52A1100, Revision 5, dated February 14, 2011, are not required by this AD. \n\n(m) Exceptions to Certain Service Information \n\n\n\t(1) Where paragraph 1.E., ''Compliance,'' of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, specifies a compliance time relative to the Revision 5 issue date of that service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD. \n\t(2) Where Table 1, ''Condition'' column of Paragraph 1.E., ''Compliance,'' of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, specifies ''airplanes without either the repair or modification accomplished in accordance with previous releases of this service bulletin,'' the corresponding condition in this AD is for ''airplanes on which either a repair or modification was not accomplished before the effective date of this AD.'' \n\t(3) Where Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, specifies to contact Boeing for certain actions: Before further flight, do the repair using a method approved in accordance with the procedures specified in paragraph (n)(1) of this AD. \n\n(n) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, Seattle ACO, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. \n\t(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. \n\t(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.(4) AMOCs approved previously in accordance with AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), are approved as AMOCs for the corresponding requirements of this AD. \n\n(o) Related Information \n\n\n\t(1) For more information about this AD, contact Alan Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone (425) 917-6450; fax (425) 917-6590; email alan.pohl@faa.gov. \n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. \n\n(p) Material Incorporated by Reference \n\n\n\t(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise. \n\t(3) The following service information was approved for IBR on June 28, 2013. \n\t(i) Procedure 4, ''Surface Inspection of Aluminum Parts (Meter Display),'' of Section 51-00-00, of Part 6, ''Eddy Current,'' of Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, Revision 108, dated November 15, 2012. The revision level of this document is identified only in the letter of transmittal; no other page of this document contains this information. \n\n((Page 31394)) \n\n\n\t(ii) Procedure 23, ''Aluminum Part Surface Inspection (Impedance Plane Display),'' Section 51-00-00, of Part 6, ''Eddy Current,'' of Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, Revision 108, dated November 15, 2012. The revision level of this document is identified only in the letter of transmittal; no other page of this document contains this information. \n\t(iii) Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011. \n\t(iv) Boeing Special Attention Service Bulletin 737-52-1149, dated December 11, 2003. \n\t(4) The following service information was approved for IBR on May 16, 2000 (65 FR 19302, April 11, 2000). \n\t(i) Figure 4, of Section 51-00-00, of Part 6, of Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, dated August 5, 1997. The revision level is not specified on the title page or list of effective pages of this document. The title page of this document is not dated. Pages 1 and 2 of the list of effective pages of this document are dated August 5, 1997; page 2A is dated February 5, 1997. \n\t(ii) Figure 23, of Section 51-00-00, of Part 6, of Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, dated August 5, 1997. The revision level is not specified on the title page or list of effective pages of this document. The title page of this document is not dated. Pages 1 and 2 of the list of effective pages of this document are dated August 5, 1997; page 2A is dated February 5, 1997. \n\t(iii) Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. \n\t(5) For Boeing service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. \n\t(6) You may view this service information at FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356. For information on the availability of this material at the FAA, call 425-227-1221. \n\t(7) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede airworthiness directive (AD) 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). That AD applies to the specified products. The NPRM published in the Federal Register on August 21, 2012 (77 FR 50407). The NPRM proposed to continue to require repetitive inspections to detect cracking of the lower corners of the door frame and cross beam of the forward cargo door, and corrective actions if necessary. The NPRM also proposed to continue to require eventual modification of the outboard radius of the lower corners of the door frame and reinforcement of the cross beam of the forward cargo door, which would constitute terminating action for the existing repetitive inspections. Additionally, the NPRM proposed to revise the compliance times for the preventive modification; add certain inspections for cracks in the number 5 cross beam of the forward cargo door; and add inspections of the number 4 cross beam if cracks are found in the number 5 cross beam, and corrective actions if necessary. For certain airplanes, the NPRM also proposed to add a one-time inspection for airplanes previously modified or repaired, and a one- time inspection of the reinforcement angle for excessive shimming or fastener pull-up, and corrective actions if necessary. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal (77 FR 50407, August 21, 2012) and the FAA's response to each comment. \n\nComment Regarding Winglet Supplemental Type Certificate (STC) \n\n\n\tAviation Partners Boeing stated that installation of winglets per STC ST01219SE (http://rgl.faa.gov/regulatory_and_guidance_library/rgstc.nsf/0/2C6E3DBDDD36F91C862576A4005D64E2?OpenDocument&Highlight=st01219se) does not affect the ability to accomplish the service information or the NPRM (77 FR 50407, August 21, 2012). \n\tWe have revised paragraph (c) in this final rule, by adding new paragraph (c)(2), to state that installation of STC ST01219SE (http://rgl.faa.gov/regulatory_and_guidance_library/rgstc.nsf/0/2C6E3DBDDD36F91C862576A4005D64E2?OpenDocument&Highlight=st01219se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE is installed, a ''change in product'' AMOC approval request is not necessary to comply with the requirements of 14 CFR 39.17. For all other AMOC requests, however, the operator must request approval for an AMOC in accordance with the procedures specified in paragraph (n) of this AD. \n\nRequest To Add New Requirements \n\n\n\tBoeing asked that we add a new paragraph (k) to the NPRM (77 FR 50407, August 21, 2012) titled ''New Inspections and Corrective Actions to Ensure Cross Beam Reinforcement,'' and suggested language for that new requirement. Boeing stated that the intent of the NPRM and Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, is to ensure that all forward cargo doors have the reinforcing modifications installed on both the beam and the frame at the forward and aft lower corners of the door. Boeing added that the current language in the NPRM and this service information leave open the potential that some doors might not have the reinforcing modification on the aft end of the cross beam, even though the doors were modified as specified in Boeing Service Bulletin 737-52-1100, dated August 25, 1988, or Revision 1, dated July 20, 1989; or in accordance with the requirements of AD 90-06-02, Amendment 39-6489 (55 FR 8372, March 7, 1990). \n\tWe do not agree with the commenter's request to add a new requirement to this AD. Boeing Service Bulletin 737-52-1100, dated August 25, 1988; and Revision 1, dated July 20, 1989; includes modifications of the forward corner of the door frame and forward end of the lower cross beam, but no modifications of the aft end of the door. Modifications of the aft corner of the door frame and aft end of the lower cross beam were added in Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994, was required by paragraph (c) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), as terminating action for the repetitive inspections. Paragraph (c) of AD 2000-07-06 is restated in paragraph (i) of this AD, and addresses airplanes on which no modification was accomplished previously. \n\tThe intent of paragraph (d) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), which is restated in paragraph (j) of this AD, was to address airplanes on which a \n\n((Page 31391)) \n\nmodification was previously accomplished in accordance with Boeing Service Bulletin 737-52-1100, dated August 25, 1988; or Revision 1, dated July 20, 1989; and to ensure that both the forward and aft ends of the lower beam of the door were modified, as well as the forward and aft corners of the door frame. Therefore, Boeing Service Bulletin 737- 52-1100, Revision 2, dated March 31, 1994, was required by AD 2000-07- 06 for those modifications. However, paragraph (d) of AD 2000-07-06 and paragraph (j) of this AD do not specify modifying the aft end of the lower beam. \n\tWe have made no change to the AD in regard to Boeing's request. However, we are considering proposing additional rulemaking in the near future to address this issue. \n\nExplanation of Change to Final Rule \n\n\n\tWe have changed paragraph (g) of this final rule to specify performing the inspection in accordance with Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, Part 6, Section 51-00-00, Procedure 4 or Procedure 23, Revision 108, dated November 15, 2012, as applicable. The subject procedures were referred to as figures in the NPRM (77 FR 50407, August 21, 2012). Because of a publishing system change in this revision of the NDT manual, the term ''figure'' was changed to ''procedure.'' The technical instructions in the NDT manual were not changed. \n\nConclusion \n\n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the change described previously. We also determined that this change will not increase the economic burden on any operator or increase the scope of the AD. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 581 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Inspections retained from AD 2000- 1 work-hour x $85 $0 $85 per inspection $49,385 per \n\t07-06, Amendment 39-11660 (65 FR per hour = $85 per cycle. inspection cycle. \n\t19302, April 11, 2000). inspection cycle. Modification retained from AD 18 work-hours x $85 $1,865 $3,395............. $1,972,495. \n\t2000-07-06. per hour = $1,530. Inspections, new action.......... 9 work-hours x $85 $0 $765............... $444,465. \n\tper hour = $765. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe estimate the following costs to do any necessary modifications that would be required based on the results of the inspections. We have no way of determining the number of aircraft that might need these modifications: \n\n\n\tOn-Condition Costs ----------------------------------------------------------------------------------------------------------------Cost per \n\tAction Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Modification.................................. 84 work-hours x $85 per hour = $12,395 $19,535 \n\t$7,140. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe have received no definitive data that would enable us to provide cost estimates for the on-condition repairs/replacements specified in this AD. \n\nAuthority for This Rulemaking \n\n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, ''General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\n\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a ''significantrule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\t(3) Will not affect intrastate aviation in Alaska, and \n\t(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.