AD 96-07-10

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-100, -200, and -300 series airplanes, that requires an inspection to determine if hinge bolts and nuts are installed in the overhead stowage bins, and the installation of hinge bolts and nuts, if necessary. This amendment is prompted by reports that overhead stowage bins in the passenger compartment have fallen out of position due to missing hinge bolts. The actions specified by this AD are intended to ensure that hinge bolts are installed in the overhead stowage bins. Missing hinge bolts could result in the overhead stowage bins falling out of position and injuring airplane occupants.

Final rule

96-07-10 BOEING: Amendment 39-9559. Docket 95-NM-93-AD. \n\n\tApplicability: Model 747-100, -200, and -300 series airplanes, as listed in Boeing Alert Service Bulletin 747-25A3095, Revision 1, dated September 28, 1995; certificated in any category. \n\n\tNOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated. \n\n\tTo ensure that hinge bolts are installed in the overhead stowage bins, accomplish the following: \n\n\t(a)\tWithin 90 days after the effective date of this AD, unless accomplished previously within the last 18 months prior to the effective date of this AD, perform a one-time visual inspection to determine if hinge bolts and nuts are installed in the overhead stowage bins, in accordance with either Boeing Alert Service Bulletin 747-25A3095, dated April 27, 1995, or Revision 1, dated September 28, 1995. \n\n\t\t(1)\tIf the hinge bolts and nuts are installed, no further action is required by this AD. \n\n\t\t(2)\tIf any hinge bolt or nut is not installed, prior to further flight, install a hinge bolt and nut in accordance with either alert service bulletin. \n\n\t(b)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(c)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(d)\tThe actions shall be done in accordance with Boeing Alert Service Bulletin 747-25A3095, dated April 27, 1995, or Boeing Alert Service Bulletin 747-25A3095, Revision 1, dated September 28, 1995. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(e)\tThis amendment becomes effective on May 6, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Boeing Model 747-100, -200, and -300 series airplanes was published as a supplemental notice of proposed rulemaking in the Federal Register on January 9, 1996 (61 FR 634). That action proposed to require an inspection to determine if hinge bolts and nuts are installed in the overhead stowage bins, and the installation of hinge bolts and nuts, if necessary. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\n\tOne commenter supports the proposed rule. \n\n\tOne commenter states that the inspection required by the proposed rule is a relatively simple inspection, and the issuance of an AD should not be required. The FAA infers that the commenter requests the AD be withdrawn. The FAA does notconcur. According to section 39.1 ("Airworthiness Directives") of the Federal Aviation Regulations (14 CFR 39.1), the issuance of an AD is based on the finding that an unsafe condition exists or is likely to develop in aircraft of a particular type design. The responsibilities placed on the FAA by the Federal Aviation Act do not limit it from making any unsafe condition -- whether resulting from maintenance, design defect, or otherwise -- the proper subject of an AD. Regardless of whether the corrective action is easy or difficult to perform, the FAA has determined that the corrective action must be accomplished in order to eliminate or prevent the identified unsafe condition. Issuance of an AD is the appropriate vehicle for ensuring that the corrective action is accomplished on all affected airplanes. \n\n\tAnother commenter states that some stowage bin support panels separated due to damaged honeycomb cores (the connection point for the hinge bolts), not due to the absence of hinge bolts, as stated in the proposed AD. The commenter also states that it installed an enlarged blade assembly on the panels, and this corrected the problem. While this commenter does not request that the proposed rule be changed, the FAA infers that the commenter is requesting that the proposed rule be withdrawn. In that case, the FAA does not concur. Investigation of damaged stowage bin support panels in service revealed that the stowage bin support panel separated because the hinge bolts were not installed during maintenance; these occurrences prompted the issuance of the proposed rule. Missing hinge bolts could result in the overhead stowage bins falling out of position and injuring airplane occupants. Additionally, the stowage bin support panels themselves must be in good condition in order to support the interface of the hinge bolts. Prudent operators performing the inspection of the hinge bolts required by this AD would likely address any damage found of the honeycomb cores of the panels or any damage detected of the bin. The FAA has been advised that Boeing is currently developing service information to address the repair of the bins. When this information is reviewed and approved, the FAA may consider further rulemaking. \n\n\tOne commenter requests that the compliance time for the inspection be extended from the proposed 90 days to 150 days. This commenter considers that extending it by another 60 days would allow operators to accomplish the inspection during regularly scheduled maintenance, and would prevent any disruption of service. The FAA does not concur. In developing the compliance time for this rulemaking action, the FAA took into consideration not only the safety implications associated with the addressed unsafe condition, but parts availability, fleet utilization rates, and normal maintenance schedules for the majority of affected operators. In consideration of these factors, the FAA finds that the 90-day compliance time is appropriate for the one-time inspection required by this AD. Additionally, the AD provides "credit" to operators who have performed this inspection within the last 18 months prior to the effective date of the AD. However, paragraph (b) of the final rule does provide affected operators the opportunity to apply for an adjustment of the compliance time if data are presented to justify such an adjustment. \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\n\tThere are approximately 573 Model 747-100, -200, and -300 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 157 airplanes of U.S. registry would be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the ADon U.S. operators is estimated to be $9,420, or $60 per airplane. \n\n\tThe cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. \n\n\tThe regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \n\n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."\n\n List of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n \nAdoption of the Amendment \n\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 USC 106(g), 40113, 44701. § 39.13 - (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: