AD 96-18-04

This amendment supersedes two existing airworthiness directives (AD), applicable to certain Boeing Model 737-300, -400, and -500 series airplanes, that currently require modification of the packing and slide containers of the escape slide, and repetitive inspections of the velcro girt retaining straps of the escape slides at the forward door. The existing AD's were prompted by reports of slide girt material interfering with the girt bar stowage brackets during door opening. This new amendment requires the installation of a new modification, which constitutes terminating action for the repetitive inspection requirements. The actions specified by this amendment are intended to prevent failure or interference of opening of the forward doors, which could delay or impede the evacuation of passengers during an emergency.

Final rule

96-18-04 BOEING: Amendment 39-9728. Docket 95-NM-138-AD. Supersedes AD 88-07-07, amendment 39-5884; and supersedes AD 91-24-04, amendment 39-8090.\n \n\tApplicability: Model 737-300, -400, and -500 series airplanes, line numbers up to and including 2211; equipped with Air Cruisers forward door escape slides as listed in Air Cruisers Company Service Bulletin S.B. 103-25-19, Revision 7, dated April 18, 1996; 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 (d) 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, unless accomplished previously. \n\n\tTo prevent failure or interference of opening of the forward doors, which could delay or impede the evacuation of passengers during an emergency, accomplish the following: \n\n\t(a)\tWithin 30 days after December 17, 1991 (the effective date of 91-24-04, amendment 39-8090), establish operating procedures, approved by the FAA Principal Maintenance Inspector (PMI), for the forward doors to include the requirements specified in paragraphs (a)(1), (a)(2), and (a)(3) of this AD; and thereafter, comply with those procedures until the modification required by paragraph (c) of this AD is accomplished. The procedures required by paragraphs (a)(1) and (a)(2) of this AD must be accomplished by qualified and trained mechanics. The procedures required by paragraph (a)(3) may be accomplished by qualified and trained members of the flightcrew or cabin crew. The training program to implement the procedures required by this paragraph must be approved by the FAA PMI. Methods for documentation of compliance with the following procedures must be approved by the FAA PMI. \n\n\t\t(1)\tPrior to the next flight after December 17, 1991, and thereafter at intervals not to exceed 200 flight hours, inspect the condition of the girt retaining straps at the forward doors. \n\n\t\t(2)\tPrior to further flight after December 17, 1991, replace worn or aged velcro whose grip strength will no longer hold the girt retaining straps in position. \n\n\t\t(3)\tPrior to the next flight after December 17, 1991, and thereafter prior to each flight, inspect the routing of the girt retaining straps at the forward doors, and reroute straps that are found not to be routed in accordance with the placarded instructions installed in accordance with AD 88-07-07, amendment 39-5884, on the inboard face of the slide compartment. \n\n\t(b)\tFor Model 737-300 series airplanes: Within 6 months after May 9, 1988 (the effective date of AD 88-07-07, amendment 39-5884), modify the escape slide packing and slide containers in accordance with Boeing Alert Service Bulletin 737-25A1221, dated December 17, 1987, or Revision 1, dated June 2, 1988. This modification must be accomplished prior to or in conjunction with accomplishment of the requirements of paragraph (c) of this AD. \n\n\t(c)\tWithin 36 months after the effective date of this AD, modify the escape slide girts in accordance with Air Cruisers Company Service Bulletin S.B. 103-25-19, Revision 7, dated April 18, 1996. Accomplishment of the modification constitutes terminating action for the repetitive inspections required by paragraph (a) of this AD. Once this modification is installed, the placard and velcro straps (and their attach points) required by the modification specified in paragraph (b) of this AD may be removed. \n\n\tNOTE 2: Accomplishment of this modification prior to the effective date of this AD in accordance with previous revisions of Air Cruisers Company Service Bulletin S.B. 103-25-19 is considered acceptable for compliance with the requirements of this paragraph. \n\n\t(d)\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\n\t(e)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(f)\tExcept as indicated in NOTE 2 of this AD, the terminating modification shall be done in accordance with Air Cruisers Company Service Bulletin S.B. 103-25-19, Revision 7, dated April 18, 1996. 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 Air Cruisers Company, P.O. Box 180, Belmar, New Jersey 07719-0180. 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(g)\tThis amendment becomes effective on October 4, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding both AD 88-07-07 (amendment 39-5884 (53 FR 9864, March 28, 1988)) and AD 91-24-04 (amendment 39-8090 (56 FR 57588, November 13, 1991)) was published as a Notice of Proposed Rulemaking (NPRM) in the Federal Register on January 19, 1996 (61 FR 1291). Both of the existing AD's are applicable to various Boeing Model 737 series airplanes. \n\n\tThe NPRM proposed to continue to require modification of the escape slide packing and slide containers, which was required previously by AD 88-07-07. The NPRM also proposed to continue to require repetitive inspections of the velcro girt retaining straps at the forward door of the escape slides, which was required previously by AD 91-24-04. Additionally, the NPRM proposed to require modification of the escape slide girts, which would constitute terminating action for the repetitive inspection requirements. \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 Support for the Proposal \n\n\tTwo commenters support the proposal.\n\n Request to Allow Removal of Placard \n\n\tOne commenter requests that the proposal be revised to allow operators to remove the velcro straps attach points and placard on the slide compartment cover that were installed as part of the modification required by AD 88-07-07. The commenter adds that some operators have already removed these items when they installed a modification that was approved as an alternative method of compliance with the repetitive inspections required by AD 91-24-04. \n\n\tThe FAA concurs. Once the terminating modification required by paragraph (c) of this final rule is installed, the velcro straps (and their attach points) are no longer necessary, and the placard may be confusing if it remains on the slide compartment. The FAA has revised paragraph (c) of the final rule to indicate that these items should be removed. \n\nRequest to Continue Approval of Previous Alternative Methods of Compliance \n\n\tSeveral commenters request that the proposal be revised to specify that alternative methods of compliance (AMOC) approved previously by the FAA for AD 91-24-04, continue to be considered approved for this new AD. Specifically, three commenters point out that the FAA had previously approved, as an AMOC, the accomplishment of the modification described in Air Cruisers Service Bulletin S.B. 103-25-23 as terminating action for the repetitive inspections required by AD 91-24- 04. These commenters request that the proposed rule likewise cite this service bulletin as an alternative terminating action. \n\n\tThe FAA does not concur. The modification described in Air Cruisers Service Bulletin S.B. 103-25-23 entails adding placards to the escape slide girt (that depict the proper stowed configuration of the girt) and removing the velcro straps that were required to be installed by AD 88-07-07. That modification, however, is reliant upon flight attendant procedures to correctly route the escape slide girt. Several recent ramp inspections of in-service airplanes have revealed that the girt material is still being misrouted, even with the placard installed. In light of this, the FAA has determined that the modification in that Air Cruisers service bulletin does not fully address the safety concern and is not as effective as the modification that is required by this new AD. \n\n\tThe modification specified in this final rule (which is described in Air Cruisers Service Bulletin S.B. 103-25-19) involves removing the existing girt; bonding on the girt attachments; installing a detachable girt; rigging a painter/mooring line; and bonding a placard to the slide assembly and reidentifying it. This modification will improve the operation of the escape slide of the forward entry and service doors, and will eliminate the need torely on human factors associated with ensuring that girt material is stowed properly. \n\nRequest to Allow Use of Revised Service Documents \n\n\tOne commenter requests that the proposal be revised to allow operators to install the terminating modification, proposed in paragraph (c), in accordance with various revisions of Air Cruisers Service Bulletin S.B. 103-25-19. The commenter points out that the service bulletin has been revised several times since the original version was released in May 1992. \n\n\tThe FAA concurs. The FAA has reviewed and approved all revisions of Air Cruisers Service Bulletin S.B. 103-25-19 through Revision 7, dated April 18, 1996. The various revisions are essentially identical, except for certain minor editorial changes. The FAA has revised paragraph (c) of the final rule to indicate that accomplishing the modification in accordance with any of these revisions is acceptable for compliance with that paragraph. \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 with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 1,572 Model 737-300, -400, and -500 series airplanes, equipped with Air Cruisers forward door escape slide of the affected design in the worldwide fleet. The FAA estimates that 663 airplanes of U.S. registry will be affected by this proposed AD. \n\n\tThe actions that are currently required by AD 88-07-07 take approximately 9 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts cost approximately $76 per airplane. Based on these figures, the cost impact on U.S. operators (175 airplanes) of the actions currently required is estimated to be $107,800, or $616 per airplane.The actions that are currently required by AD 91-24-04 take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact on U.S. operators (439 airplanes) of the actions currently required is estimated to be $26,340, or $60 per airplane, per inspection cycle. \n\n\tThe terminating modification that is required by this new AD will take approximately 6 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts cost approximately $1,800 per airplane. Based on these figures, the cost impact on U.S. operators of the new modification requirements of this AD is estimated to be $1,432,080, or $2,160 per airplane. \n\n\tThis 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\nRegulatoryImpact \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\n PART 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\n\t2. Section 39.13 is amended by removing amendments 39-5884 (53 FR 9864, March 28, 1988) and 39-8090 (56 FR 57588, November 13, 1991), and by adding a new airworthiness directive (AD), amendment 39-9728, to read as follows: