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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2010-0132; Directorate Identifier 2009-NM-096-AD]
RIN 2120-AA64
 AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT).
 ACTION: Notice of proposed rulemaking (NPRM).
 SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Model 747-100, 747-200B, and -200F series airplanes. The existing AD currently requires inspections to detect cracking in the upper row of fasteners holes of the skin lap joints in the fuselage lower lobe, and repair, if necessary. This proposed AD would reduce the maximum interval of the post-modification inspections. This proposed AD results from reports of fatigue cracking on modified airplanes. We are proposing this AD to detect and correct fatigue cracking in the longitudinal lap joints of the fuselage lower lobe, which could lead to the rapid decompression of the airplane and the inability of the structure to carry fail-safe loads.
 DATES: We must receive comments on this proposed AD by April 12, 2010.
 ADDRESSES: You may send comments by any of the following methods:
                        ( print page 8555) *Federal eRulemaking Portal:*
                         Go to 
                        *http://www.regulations.gov*. Follow the instructions for submitting comments.
                    *Fax:*
                         202-493-2251.
                    *Mail:*
                         U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
                    *Hand Delivery:*
                         U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this proposed 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; e-mail 
                        *me.boecom@boeing.com;*
                         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 or 425-227-1152. Examining the AD Docket You may examine the AD docket on the Internet at 
                    *http://www.regulations.gov*; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800-647-5527) is in the 
                    **ADDRESSES**
                     section. Comments will be available in the AD docket shortly after receipt.
 FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590.


SUPPLEMENTARY INFORMATION:  Comments Invited We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the 
                    **ADDRESSES**
                     section. Include “Docket No. FAA-2010-0132; Directorate Identifier 2009-NM-096-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments. We will post all comments we receive, without change, to 
                    *http://www.regulations.gov*, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD. Discussion On August 4, 1994, we issued AD 94-17-01, Amendment 39-8996 (59 FR 41653, August 15, 1994), for certain Model 747 series airplanes. That AD requires inspections to detect cracking in the upper row of fastener holes of the skin lap joints in the fuselage lower lobe, and repair if necessary. That AD resulted from reports of incidents involving fatigue cracking and corrosion of transport category airplanes that are approaching or have exceeded their design life goal. We issued that AD to prevent separation of fuselage skin and rapid loss of pressure in the airplane. Actions Since Existing AD Was Issued Since we issued AD 94-17-01, Boeing has performed a fleet-wide evaluation of the skin panel lap joints for widespread fatigue damage (WFD) and determined that the post-modification inspection interval of AD 94-17-01 needs to be reduced. In addition, lap joints where the upper (overlapping) skin thickness at the upper row of fasteners is 0.071 inch or less need to be further modified to preclude WFD. WFD of the lap joints can link up and result in large skin cracks, and possible rapid in-flight decompression of the airplane. Relevant Service Information AD 94-17-01 referred to Boeing Service Bulletin 747-53A2267, Revision 3, dated March 26, 1992, as the appropriate source of service information. Boeing has since issued Alert Service Bulletin 747-53A2267, Revision 4, dated March 26, 2009. This service bulletin reduces the repetitive interval for the post-modification inspections and references a structural modification for lap joints where the upper (overlapping) skin thickness at the upper row of fasteners is 0.071 inch or less. Related Rulemaking We are considering issuing related rulemaking to address the identified unsafe condition. We are in the process of issuing an AD that will refer to Revision 1 of Boeing Alert Service Bulletin 747-53A2463, and is related to this issue. That AD will require further modification of all the affected lap joints with an upper skin thickness of 0.071 inch or less. FAA's Determination and Requirements of the Proposed AD We have evaluated all pertinent information and identified an unsafe condition that is likely to develop on other airplanes of the same type design. For this reason, we are proposing this AD, which would supersede AD 94-17-01. This AD would retain the requirements of that AD using the revised service information, and reduce the maximum interval of the post-modification inspections from 3,000 flight cycles to 1,000 flight cycles. Differences Between the Proposed AD and Service Bulletin Boeing Alert Service Bulletin 747-53A2267, Revision 4, dated March 26, 2009, specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways: Using a method that we approve; or
                Using data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization that we have authorized to make those findings. Changes to Existing AD This proposed AD would retain the requirements of AD 94-17-01. Since AD 94-17-01 was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table: Revised Paragraph Identifiers
Requirement in
                             AD 94-17-01
Corresponding 
                             requirement in this proposed ADParagraph (a)
Paragraph (g).Paragraph (b)
Paragraph (h).Paragraph (c)
Paragraph (i).
 This proposed AD identifies the legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models. Costs of Compliance There are about 23 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.
                    ( print page 8556) Estimated Costs
Action
Work hours
Average labor rate per hour
Parts
Cost per airplane
Number of U.S.
                             -registered 
                             airplanes
Fleet costInspection (required by AD 94-17-01)
244
$85
$0
$20,740 per inspection cycle
7
$145,180 per inspection cycle.
 Authority for This Rulemaking Title 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. We 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. Regulatory Findings We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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. For the reasons discussed above, I certify that the proposed regulation: 1. Is not a “significant regulatory action” under Executive Order 12866; 2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. 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. We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the 
                    **ADDRESSES**
                     section for a location to examine the regulatory evaluation. List of Subjects in 14 CFR Part 39 Air transportation
Aircraft
Aviation safety
Incorporation by reference
Safety
 The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39—AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority:
                        49 U.S.C. 106(g), 40113, 44701. § 39.13
  2. The FAA amends § 39.13 by removing Amendment 39-8996 (59 FR 41653, August 15, 1994) and adding the following new AD: **The Boeing Company:**
                                 Docket No. FAA-2010-0132; Directorate Identifier 2009-NM-096-AD. Comments Due Date (a) The FAA must receive comments on this AD action by April 12, 2010. Affected ADs (b) This AD supersedes AD 94-17-01, Amendment 39-8996. Applicability (c) This AD applies to The Boeing Company Model 747-100, 747-200B, and 747-200F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2267, Revision 4, dated March 26, 2009. Subject (d) Air Transport Association (ATA) of America Code 53: Fuselage. Unsafe Condition (e) This AD results from reports of fatigue cracking. The Federal Aviation Administration is issuing this AD to detect and correct fatigue cracking in the fuselage lower lobe longitudinal lap joints, which could lead to the rapid decompression of the airplane and the inability of the structure to carry fail-safe loads. Compliance (f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. *Restatement of Requirements of AD 94-17-01, with Revised Compliance Times for Post-Modification Inspection and Revised Service Information:* Initial External High Frequency Eddy Current Inspection (g) Perform an external high frequency eddy current inspection to detect cracks in the upper row of fasteners in the modified lap joints in accordance with Boeing Service Bulletin 747-53A2267, Revision 3, dated March 26, 1992; or Revision 4, dated March 26, 2009; at the time specified in paragraph (g)(1) or (g)(2) or (g)(3) of this AD, as applicable. As of the effective date of this AD, only Revision 4 may be used. (1) For airplanes on which the full modification required by AD 90-06-06, Amendment 39-6490, has been accomplished in accordance with Revision 2 of Boeing Service Bulletin 747-53A2267, dated March 29, 1990; or Revision 3, dated March 26, 1992; or Revision 4, dated March 26, 2009: Prior to the accumulation of 10,000 flight cycles after accomplishment of the full modification. (2) For airplanes on which the full modification required by AD 90-06-06 has been accomplished in accordance with Boeing Service Bulletin 747-53A2267, dated March 28, 1986; or Revision 1, dated September 25, 1986: Prior to the accumulation of 7,000 flight cycles after accomplishment of the full modification. (3) For airplanes on which the optional modification has been accomplished in accordance with Boeing Service Bulletin 747-53A2267, Revision 2, dated March 29, 1990; or Revision 3, dated March 26, 1992; or Revision 4, dated March 26, 2009: Prior to the accumulation of 7,000 flight cycles after accomplishment of the optional modification. Repetitive External High Frequency Eddy Current Inspections (h) If no cracking is detected during the inspection required by paragraph (g) of this AD, repeat the inspection required by paragraph (g) of this AD at the earlier of the times specified in paragraphs (h)(1) and (h)(2) of this AD, and thereafter at intervals not to exceed 1,000 flight cycles. (1) Within 3,000 flight cycles after the last inspection required by paragraph (g) of this AD. (2) Within 1,000 flight cycles after the last inspection required by paragraph (g) of this AD or 500 flight cycles after the effective date of this AD, whichever occurs later. Repair (i) If any cracking is detected during any inspection required by paragraph (g) of this 
                                ( print page 8557)
                                AD, prior to further flight, repair in accordance with Section 53-30-03 of the Boeing 747 Structural Repair Manual (SRM); or Boeing Alert Service Bulletin 747-53A2267, Revision 4, dated March 26, 2009; except as required by paragraph (j) of this AD; and repeat the inspection required by paragraph (g) of this AD at the times specified in paragraph (i)(1) of this AD. After the effective date of this AD, use only Boeing Alert Service Bulletin 747-53A2267, Revision 4, dated March 26, 2009. (1) As of the effective date of this AD: If the repair specified in the Boeing 747 SRM does not include removing the lap joint and the upper row of countersunk fasteners, repeat the inspection required by paragraph (g) of this AD at the earlier of the times specified in paragraphs (i)(1)(i) and (i)(1)(ii) of this AD, and thereafter at intervals not to exceed 1,000 flight cycles. (i) Within 3,000 flight cycles after the last inspection required by paragraph (g) of this AD. (ii) Within 1,000 flight cycles after the last inspection required by paragraph (g) of this AD, or within 500 flight cycles after the effective date of this AD, whichever occurs later. (2) If the repair specified in the 747 SRM includes removing the lap joint and the upper row of countersunk fasteners, such repair constitutes terminating action for the inspection requirements of this AD. Exception to the Service Bulletin (j) If any cracking is found during any inspection required by this AD, and Boeing Alert Service Bulletin 747-53A2267, Revision 4, dated March 26, 2009, specifies contacting Boeing for appropriate action: Before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (k) of this AD. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically refer to this AD. Alternative Methods of Compliance (AMOCs) (k)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590. Or, e-mail information to 
                                *9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.* (2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. (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 Organization Designation Authorization (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 94-17-01 are approved as AMOCs for the corresponding provisions of this AD.
 Issued in Renton, Washington, on February 17, 2010. Stephen P. Boyd, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.


[FR Doc. 2010-3819 Filed 2-24-10; 8:45 am] BILLING CODE 4910-13-P