AD 99-17-20

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 757-200 and -300 series airplanes, that requires modification of the off-wing emergency evacuation slide system. This amendment is prompted by reports that a certain type of off-wing escape slide aboard several airplanes separated from the airplane during flight. The actions specified by this AD are intended to prevent separation of the emergency evacuation slide from the airplane, which could result in damage to the fuselage and unavailability of an escape slide during an emergency evacuation.

Final rule

99-17-20 BOEING: Amendment 39-11266. Docket 99-NM-06-AD. \n\n\tApplicability: Model 757-200 and -300 series airplanes equipped with off-wing emergency evacuation slides, as listed in Boeing Service Bulletin 757-25-0182, Revision 1, dated June 12, 1997, or Boeing Service Bulletin 757-25-0200, dated January 21, 1999; 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 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 hasnot been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent separation of the emergency evacuation slide from the airplane, which could result in damage to the fuselage and unavailability of an escape slide during an emergency evacuation, accomplish the following: \n\nModification \n\n\t(a)\tWithin 18 months after the effective date of this AD: Modify the left and right off-wing emergency evacuation slide systems by accomplishment of paragraph (a)(1) or (a)(2) of this AD, as applicable. \n\n\t\t(1)\tFor airplanes listed in Boeing Service Bulletin 757-25-0182, Revision 1, dated June 12, 1997: Modify the door latch system of the left and right off-wing emergency evacuation slide systems in accordance with the service bulletin. \n\n\tNOTE 2: Modification of the door latch system of the off-wing emergency evacuation slide system, prior to the effective date of this AD, in accordance with Boeing Service Bulletin 757-25-0182, dated October 10, 1996, is considered acceptable for compliance with paragraph (a)(1) of this AD. \n\n\t\t(2)\tFor airplanes listed in Boeing Service Bulletin 757-25-0200, dated January 21, 1999: Install a bumper assembly on the bottom of the left and right off-wing escape slide carriers, and install new placards in the area of the maintenance access door, in accordance with the service bulletin. \n\nAlternative Methods of Compliance \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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\nSpecial Flight Permits \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\nIncorporation by Reference \n\n\t(d)\tThe actions shall be done in accordance with Boeing Service Bulletin 757-25-0182, Revision 1, dated June 12, 1997, or Boeing Service Bulletin 757-25-0200, dated January 21, 1999; as applicable. 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 September 24, 1999.

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 757-200 and -300 series airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on June 11, 1999 (64 FR 31523). That action proposed to require modification of the off-wing emergency evacuation slide system. \n\nComments \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\nSupport for the Proposal \n\n\tThree commenters support the proposed rule, and one commenter states that the rule does not affect it. \n\nRequest to Delay Effective Date \n\n\tOne commenter supports the proposed rule, but requests that the effective date of the AD be set after July 31, 1999, to allow the scheduled modification to be accomplished during the operator's scheduled "4C" check. The FAA notes that the effective date of the AD will be after July 31, 1999. No change to the final rule is necessary. \n\nRequest to Require New Repetitive Inspections \n\n\tOne commenter to the NPRM that preceded the supplemental NPRM favors adding a requirement for a functional test to the proposed AD. The commenter requests that the FAA consider rulemaking to require repetitive tests of the emergency evacuation slides on each airplane to ensure that they work properly. \n\n\tThe FAA does not concur with the commenter's request. Adding a requirement to this final rule would require the issuance of a new supplemental notice of proposed rulemaking to reopen the public comment period. To delay this final rule in this way would be inappropriate, because the FAA has determined that an unsafe condition exists and the required actions must be accomplished to ensure continued safety. The FAA notes, however, that operators are required, per their maintenance procedures, to periodically deploy one escape slide on one airplane in its fleet to ensure proper function. No change to the final rule is necessary. \n\nConclusion \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\nCost Impact \n\n\tThere are approximately 503 Model 757-200 and-300 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 441 airplanes of U.S. registry will be affected by this AD. \n\n\tFor airplanes identified in Boeing Service Bulletin 757-25-0182, Revision 1 (301 U.S.-registered airplanes), it will take approximately 40 work hours per airplane to accomplish the required modification of the door latch system, at an average labor rate of $60 per work hour. Required parts will cost approximately $1,450 per airplane. Based on these figures, the cost impact of the required modification on U.S. operators is estimated to be $1,158,850, or $3,850 per airplane. \n\n\tFor airplanes identified in Boeing Service Bulletin 757-25-0200 (441 U.S.-registered airplanes), it will take approximately 4 work hours to accomplish the required installation of the bumper assembly and placards, at an average labor rate of $60 per work hour. Required parts will cost approximately $457 per airplane. Based on these figures, the cost impact of the required installation on U.S. operators is estimated to be $307,377, or $697 per airplane. \n\n\tThe cost impact figures discussed above are 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\nRegulatory Impact \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\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\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 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: