AD 2009-02-06

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-300, -400, and -500 series airplanes. This AD requires repetitive high frequency eddy current inspections for cracking of the 1.04-inch nominal diameter wire penetration hole in the frame and frame reinforcement, between stringers S-20 and S-21, on both the left and right sides of the airplane, and related investigative and corrective actions if necessary. This AD results from reports of cracking in the frame, or in the frame and frame reinforcement, common to the 1.04-inch nominal diameter wire penetration hole intended for wire routing. We are issuing this AD to detect and correct cracking in the fuselage frames and frame reinforcements, which could reduce the structural capability of the frames to sustain limit loads, and result in cracking in the fuselage skin and subsequent rapid depressurization of the airplane.

Final rule.

2009-02-06 Boeing: Amendment 39-15796. Docket No. FAA-2008-0671; Directorate Identifier 2008-NM-017-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective April 15, 2009. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 737-300, -400, and -500 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007. \n\nUnsafe Condition \n\n\t(d) This AD results from reports of cracking in the frame, or in the frame and frame reinforcement, common to the 1.04-inch nominal diameter wire penetration hole intended for wire routing. We are issuing this AD to detect and correct cracking in the fuselage frames and frame reinforcements, which could reduce the structural capability of the frames to sustain limit loads, and result in cracking in the fuselage skin and subsequent rapid depressurization of the airplane. \n\nCompliance \n\n\t(e) Comply with this AD within thecompliance times specified, unless already done. \n\nService Bulletin Reference Paragraph \n\n\t(f) The term "service bulletin,'' as used in this AD, means the Accomplishment Instructions of Boeing Alert Service Bulletin 737- 53A1279, dated December 18, 2007. \n\t(1) The "condition'' column of paragraph 1.E. of Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007, refers to total flight cycles "at the date given on this service bulletin.'' This AD applies to the airplanes with the specified total flight cycles as of the effective date of this AD. \n\t(2) Where the service bulletin specifies to contact Boeing for instructions for removing damage and repairing cracking: Before further flight, remove the damage or repair the cracking using a method approved in accordance with the procedures specified in paragraph (i) of this AD. \n\t(3) Although the service bulletin referenced in this AD specifies to submit information to the manufacturer, this AD does not include that requirement. \n\nInspections, Related Investigative and Corrective Actions \n\n\t(g) At the applicable time specified in paragraph 1.E., "Compliance,'' of the service bulletin, except as specified by paragraph (f)(1) of this AD: Do a high frequency eddy current (HFEC) surface inspection or an HFEC hole/edge inspection for cracking of the 1.04-inch nominal diameter wire penetration hole in the frame and frame reinforcement, between stringer S-20 and S-21; and do all applicable related investigative and corrective actions; by accomplishing all the actions specified in the Accomplishment Instructions of the service bulletin, except as specified by paragraphs (f)(2) and (f)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Thereafter, repeat the inspections at the applicable intervals specified in paragraph 1.E. of the service bulletin. \n\nTerminating Action \n\n\t(h) Doing the repair in Part 3 or the preventative modification in Part 5 of the service bulletin terminates the repetitive inspection requirements of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM- 120S, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6447; fax (425) 917-6590; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. \n\t(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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. \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 an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who 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. \n\nMaterial Incorporated by Reference \n\n\t(j) You must use Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \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; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\t(3) You may review copies of the service information incorporated by reference 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. \n\t(4) You may also review copies of the service information 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/code_of_federal_ regulations/ibr_locations.html.

Discussion \n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 737-300, -400, and -500 series airplanes. That NPRM was published in the Federal Register on June 24, 2008 (73 FR 35598). That NPRM proposed to require repetitive high frequency eddy current (HFEC) inspections for cracking of the 1.04-inch nominal diameter wire penetration hole in the frame and frame reinforcement, between stringers S-20 and S-21, on both the left and right sides of the airplane, and related investigative and corrective actions if necessary. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We considered the comments received from the single commenter. \n\nRequest To Revise Paragraph (h) To Correct References to Parts of the Service Bulletin \n\n\tKLM Royal Dutch Airlines (KLM) requests that we revise paragraph (h) of the NPRM tocorrect the references to certain parts of Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007 ("the service bulletin''), for doing certain actions. KLM points out that paragraph (h) of the NPRM refers to Part 3 of the service bulletin for doing the repair and to Part 4 of the service bulletin for doing the preventative modification. KLM further points out that Part 4 of the service bulletin concerns repeat inspections, not the preventative modification. The preventative modification is provided in Part 5 of the service bulletin. \n\tWe agree with the commenter. It was our intention to refer to Part 5 of the service bulletin for doing the preventative modification provided in paragraph (h) of the NPRM. Therefore, we have revised paragraph (h) of this AD to refer to Part 5 of the service bulletin for doing the preventative modification. \n\nRequest To Revise Paragraph (e) To Clarify Compliance Times \n\n\tKLM requests that we revise paragraph (e) of the NPRM to refer to paragraph 1.E., "Compliance,'' of the service bulletin. KLM asserts that adding a reference to the location of the compliance times in the service bulletin would be helpful. \n\tWe do not agree to revise paragraph (e) of this AD. A reference to paragraph 1.E., "Compliance,'' of Boeing Service Bulletin 737-53A1279, dated December 18, 2007, is already provided in paragraph (g) of this AD. \n\nConclusion \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\tWe estimate that this AD affects 616 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this AD. The average labor rate is $80 per work hour. \n\n\tEstimated Costs \n\n\nAction\nWork hours\nParts\nCost per product\nNumber of U.S.-registered airplanes\nFleet cost\nInspection\nBetween 6 and 8 (depending on airplane configuration), per inspection cycle\n$0\nBetween $480 and $640, per inspection cycle\n616\nBetween $295,680 and $394,240, per inspection cycle\n\nAuthority for This Rulemaking \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 authoritybecause it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tThis 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 "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and \n\t(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. \n\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by adding the following new AD: