AD 97-19-03

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 737 series airplanes, that currently requires an inspection to determine whether the bearings of the tracklock bracket assemblies of the pilot and co-pilot seats are secure, modification of loose bearings, and marking of the seat identification labels. This AD requires a visual inspection to determine whether the modification and marking of the crew seats were accomplished; and, if not, accomplishment of these actions, which constitutes terminating action for the requirements of this AD. This amendment is prompted by a report indicating that a first officer's crew seat on an in-service airplane failed to lock horizontally. The actions specified in this AD are intended to prevent the captain and first officer crew seats from sliding freely on the track, which could result in uncommanded movement of the seats and reduced controllability of the airplane.

Final rule; request for comments.

97-19-03 BOEING: Amendment 39-10123. Docket 97-NM-168-AD. Supersedes AD 93-15-08 R1, Amendment 39-8686. \n\tApplicability: Model 737 series airplanes equipped with IPECO Model 093 captain and first officer crew seats, having seat serial numbers up to and including 21121; 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 (c) 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 requestshould include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent the captain and first officer crew seats from sliding freely on the track, which could result in uncommanded movement of the seats and reduced controllability of the airplane, accomplish the following: \n\n\t(a)\tWithin 90 days after the effective date of this AD, perform a visual inspection of the seat identification labels of the captain and first officer crew seats to determine whether these seats were modified by installing a bearing retaining pin in the tracklock bracket assembly of the seats, and whether the seats were marked by an identification label, in accordance with IPECO Service Bulletin A001-25-74, Issue 2, dated May 6, 1993, or IPECO Service Bulletin A001-25-92, Issue 1, dated June 2, 1997. \n\n\t\t(1)\tIf the modification and marking of the crew seats were accomplished in accordance with service bulletin A001-25-74 or A001-25-92, no further action is required by this AD. \n\n\t\t(2)\tIf the modification and marking were not accomplished in accordance with either service bulletin, within 90 days after the effective date of this AD, accomplish the modification (installation of a bearing retaining pin in the tracklock bracket assembly of the captain and first officer crew seats), and the marking of the seat identification label; in accordance with IPECO Service Bulletin A001-25-92, Issue 1, dated June 2, 1997. \n\n\t(b)\tAs of the effective date of this AD, no person shall install on any airplane a pilot/co-pilot (captain/first officer) crew seat that does not bear the marking "A001-25-74" or "A001-25-92" on the seat identification label. \n\n\t(c)\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 requeststhrough 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(d)\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(e)\tThe actions shall be done in accordance with IPECO Service Bulletin A001-25-92, Issue 1, dated June 2, 1997; or IPECO Service Bulletin A001-25-74, Issue 2, dated May 6, 1993. \n\n\t\t(1)\tThe incorporation by reference of IPECO Service Bulletin A001-25-92, Issue 1, dated June 2, 1997, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. \n\n\t\t(2)\tThe incorporation by reference of IPECO Service Bulletin A001-25-74, Issue 2, dated May 6, 1993, was approved previously by the Director of the Federal Register as of August 24, 1993 (58 FR 42192, August 9, 1993). \n\n\t\t(3)\tCopies may be obtained from IPECO, Inc., 3882 Del Amo Boulevard, suite 604, Torrance, California 90503. 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(f)\tThis amendment becomes effective on September 24, 1997.

On August 2, 1993, the FAA issued AD 93-15-08, amendment 39-8654 (58 FR 42192, August 9, 1993), applicable to certain Boeing Model 737 airplanes, to require an inspection to determine whether the bearings of the tracklock bracket assemblies of the pilot and co-pilot seats are secure, modification of loose bearings, and marking of the seat identification label. (A correction of the rule was published in the Federal Register on September 14, 1993 (58 FR 47986).) That action was prompted by reports of pilot seats failing to lock horizontally due to the tracklock pin bearing becoming detached from its housing and wedged in the mechanism. The actions required by that AD are intended to prevent the pilot and co-pilot seats from sliding freely on the track, which could lead to the inability of the pilots to control the airplane. \n\nActions Since Issuance of Previous Rule \n\n\tSince the issuance of AD 93-15-08 R1, the FAA has received a report indicating thata first officer's crew seat on a Boeing Model 737 series airplane, which had been inspected previously in accordance with IPECO Service Bulletin A001-25-74, Issue 2, dated May 6, 1993, failed to lock horizontally because the tracklock pin bearing of the tracklock bracket assembly detached from its housing and wedged in the tracklock mechanism. In addition, four reports were received of captain and first officer crew seats becoming loose after being inspected previously. Migration of the tracklock bearing from the tracklock bracket assemblies, if not corrected, could cause the crew seats to slide horizontally on the track during acceleration and takeoff of the airplane, which could result in uncommanded movement of the seats and reduced controllability of the airplane. \n\nExplanation of Relevant Service Information \n\n\tSince the issuance of the previous rule, the FAA has reviewed and approved IPECO Service Bulletin A001-25-92, Issue 1, dated June 2, 1997, which specifies proceduresfor a visual inspection of the seat identification label to determine whether the modification and marking of the captain and first officer crew seats were accomplished in accordance with the previously referenced IPECO service bulletin (A001-25-74); and, if not, procedures for such modification and marking to ensure that the seats are secure. Modification of the crew seats requires the installation of a bearing retaining pin in the tracklock bracket assemblies of the captain and first officer crew seats to ensure that these seats remain in a secure position during acceleration and takeoff of the airplane. Marking of the crew seats is accomplished by vibro etch or a similar method on the seat pan structure, beneath the pin cushion, or on the aft face of the seat base structure, following installation of the retaining pin. \n\nExplanation of Requirements of Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this AD supersedes AD 93-15-08 R1 to require a visual inspection to determine whether the modification and marking of crew seats have been accomplished; and, if not, accomplishment of such modification and marking to ensure that the seats are secure, which constitutes terminating action for the requirements of this AD. These actions are to be done in accordance with the IPECO service bulletins referenced previously.\n\nDetermination of Rule's Effective Date \n\n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. \n\nComments Invited \n\n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. \n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 97-NM-168-AD." The postcard will be date stamped and returned to the commenter. \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\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and thatit is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \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\t2. Section 39.13 is amended by removing amendment 39-8686 (58 FR 47986, September 14, 1993), and by adding a new airworthiness directive (AD), amendment 39-10123, to read as follows: