AD 96-04-07

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Airbus Model A310 and A300-600 series airplanes. This amendment requires repetitive inspections to detect distortion and/or cracks on the attachment brackets of the backrest recline control locks of certain seats. It also provides for an optional modification which, if accomplished, terminates the repetitive inspections. This amendment is prompted by a report of failure of the bracket of the backrest recline control lock on a seat due to fatigue-related cracking. The actions specified by this AD are intended to prevent fatigue-related cracking and/or distortion, which could result in failure of the seat backrest attach fitting, and the subsequent uncommanded 50 angle recline of the pilot or co-pilot seat; this situation could lead to the temporary inability of the pilots to control the airplane.

Final rule.

96-04-07 AIRBUS INDUSTRIE: Amendment 39-9519. Docket 94-NM-191-AD.

Applicability: Model A310 and A300-600 series airplanes equipped with SOGERMA- SOCEA pilot, co-pilot, and third occupant seats; as listed in SOGERMA-SOCEA Service Bulletin 25-229, dated November 26, 1993; certificated in any category.

NOTE 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 (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 request shouldinclude specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent fatigue cracks and/or distortion in the seat bracket of the backrest recline control lock, which could result in failure of the seat backrest attach fittings, the uncommanded 50 angle recline of the pilot or co-pilot seat, and, subsequently, lead to the temporary inability of the pilots to control the airplane, accomplish the following:

(a) Prior to the accumulation of 10,000 total flight hours or within 500 flight hours after the effective date of this AD, whichever occurs later, perform a detailed visual inspection to detect distortion and/or cracks on the attachment brackets of the backrest recline control locks of certain seats, in accordance with SOGERMA-SOCEA Service Bulletin 25-229, dated November 26, 1993.

(1) If no bracket is distorted or cracked, repeat the inspection thereafter at intervals not to exceed 5,000 flight hours.(2) If any bracket is distorted or cracked, prior to further flight, accomplish either paragraph (a)(2)(i) or (a)(2)(ii) of this AD.

(i) Replace both of the brackets and their associated attachment fittings with new parts, in accordance with SOGERMA-SOCEA Service Bulletin 25-229, dated November 26, 1993. Thereafter, repeat the inspection at intervals not to exceed 5,000 flight hours. Or

(ii) Modify the backing of the control locks attachment fittings of the seat backrest recline, in accordance with SOGERMA-SOCEA Service Bulletin 25-233, Revision 2, dated March 22, 1995. Accomplishment of this modification constitutes terminating action for the repetitive inspection requirements of this AD.

NOTE 2: Modification of the backing of the control locks attachment fittings of the seat backrest recline that was accomplished in accordance with SOGERMA-SOCEA Service Bulletin 25-233, Revision 1, dated March 22, 1995, prior to the effective date of this AD, is considered acceptable for compliance with paragraph (a)(2)(ii) of this AD.

(b) Modification of the backing of the control locks fittings of the backrest recline in accordance with SOGERMA-SOCEA Service Bulletin 25-233, Revision 2, dated March 22, 1995, constitutes terminating action for the repetitive inspection requirements of this AD.

NOTE 3: Modification of the backing of the control locks attachment fittings of the seat backrest recline that was accomplished in accordance with SOGERMA-SOCEA Service Bulletin 25-233, Revision 1, dated March 22, 1995, prior to the effective date of this AD, is considered acceptable for compliance with paragraph (b) of this AD.

(c) An 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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113.

NOTE 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(d) Special 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.

(e) The inspections and replacements shall be done in accordance with SOGERMA- SOCEA Service Bulletin 25-229, dated November 26, 1993. The modification shall be done in accordance with SOGERMA-SOCEA Service Bulletin 25-233, Revision 2, dated March 22, 1995, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1-4, 6-16
2
March 22, 1995
5
Original
September 14, 1994

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 Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 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.

(f) This amendment becomes effective on March 25, 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 Airbus Model A310 and A300-600 series airplanes was published in the Federal Register on June 2, 1995 (60 FR 526678) as a supplemental notice of proposed rulemaking (NPRM). That action proposed to require repetitive inspections to detect distortion and/or cracks on the attachment brackets of the backrest recline control locks of certain seats. It also proposed an optional modification which, if accomplished, would terminate the repetitive inspection requirement.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Support for the Proposal
Three commenters support the proposal.

Request to Withdraw the Proposal
One commenter requests that the proposal be withdrawn. This commenter contends that an AD is not justified based on only one incident of failure that occurred on one seat. The commenter considers that issuing an AD to address only this one occurrence is a misapplication of the AD process.

The FAA does not concur with the commenter's request. The FAA points out that the seat backrest recline lock mechanism currently is not the subject of routine maintenance to determine the presence of distortion or cracking. Therefore, cracking and distortion potentially could be present or developing on these components throughout the affected fleet. While it is true that there has been only one incident of failure of the lock mechanism identified so far, the FAA finds that the unsafe condition presented by such failure is likely to exist or develop on other products of this same type design. According to section 39.1 ("Airworthiness Directives") of the Federal Aviation Regulations (FAR) (14 CFR 39.1), the issuance of an AD must be based on just such a finding. Further, it is within the FAA's authority to issue AD's to require actions to address unsafe conditions that are not otherwise being addressed (or addressed adequately) by normal maintenance procedures. The intent of this AD is to ensure that maintenance procedures include inspections of the backrest recline lock mechanism.

Request to Extend Compliance Time
Another commenter, an operator, requests that the compliance time for the initial inspection be extended. This commenter plans to accomplish the terminating modification at a time that coincides with its normally scheduled maintenance checks and, therefore, requests that the compliance time for the inspection be extended to June 1997.

The FAA does not concur with this commenter's request. Based on the unsafe condition associated with the failure of the lock mechanism (uncommanded 50 angle recline of the pilot or co-pilot seat), the FAA considers that the compliance time for the inspection, as proposed, represents the most appropriate interval of time allowable for the affected airplanes to continue to operate prior to accomplishing that inspection without compromising safety. The FAA also finds that, in order to ensure continuing operational safety, these inspections must be repeated at regular intervals until a terminating modification is installed. However, paragraph (c) 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.

Explanation of New Service Information

On March 22, 1995, SOGERMA-SOCEA issued Revision 2 of Service Bulletin 25-233. Revision 2 completely supersedes Revision 1, which was referenced in the supplemental NPRM as the appropriate source of service information. This new revision describes new procedures for modification of the backing of the control locks attachment fittings of the seat backrest recline. This modification involves installing certain nuts, lock nuts,back plates, fittings, and flat washers on the seat bottoms. Accomplishment of this modification eliminates the need for repetitive inspections of the lock mechanism. The Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, approved this revision of the service bulletin; and the FAA has revised paragraph (b) of the final rule to cite Revision 2 as the appropriate source of service information for accomplishing the terminating modification. Modifications that were accomplished in accordance with Revision 1 of the service bulletin prior to the effective date of the final rule are considered acceptable for compliance.

Conclusion

After 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.

Cost Impact

The FAA estimates that 49 airplanes of U.S. registry will be affected by this AD, that it will take approximately 4 work hours per airplane to accomplish the required inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $11,760, or $240 per airplane, per inspection cycle.

The 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.

Should an operator elect to accomplish the optional terminating action that is provided by this AD, the number of hours required to accomplish it would be approximately 1 per airplane, at an average labor charge of $60 per work hour. Required parts would be supplied by the manufacturer at no cost to the operators. Basedon these figures, the total cost impact of the optional terminating action on U.S. operators would be $60 per airplane.

Regulatory Impact

The 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.

For 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."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, 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:
PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 USC 106(g), 40113, 44701.
39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: