AD 96-25-07

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that currently requires repetitive visual inspections and end-float checks of the ram air turbine (RAT), and replacement of the RAT, if necessary. This amendment requires installation of a modified RAT, which constitutes terminating action for the currently required inspections. This amendment is prompted by the development of a modification of the RAT that positively addresses the unsafe condition. The actions specified by this AD are intended to prevent the RAT from breaking away from its support leg, which could damage the airplane structure and systems, and could injure ground personnel.

Final rule.

96-25-07 AIRBUS INDUSTRIE: Amendment 39-9849. Docket 96-NM-164-AD. Supersedes AD 94-01-11, Amendment 39-8793.

Applicability: Model A320-111, -211, -212, -214, -231, and -232 series airplanes; on which Airbus Industrie Modification 24701 (as described in Airbus Service Bulletin A320-29- 1065, dated February 28, 1995) has not been installed; certificated in any category.

NOTE 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 (e) 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.

Compliance: Required as indicated, unless accomplished previously.

To prevent the ram air turbine (RAT) from breaking away from its support leg, which could damage the airplane structure and systems, and could injure ground personnel, accomplish the following:

(a) Perform a detailed visual inspection and an end-float check of the RAT between turbine and leg, in accordance with Airbus Industrie Service Bulletin A320-29-1061, dated April 13, 1993, at the earliest of the times specified in paragraph (a)(1), (a)(2), or (a)(3) of this AD:

(1) Within the next 450 flight hours after March 3, 1994 (the effective date of AD 94-01-11, amendment 39-8793); or

(2) Before and after the first functional ground check of the RAT that is performed after March 3, 1994; or

(3) After the first in-flight deployment of the RAT that occurs afterMarch 3, 1994.

(b) If no discrepancy is detected, repeat the detailed visual inspection and the end- float check after each functional ground check of the RAT, and after each in-flight deployment of the RAT.

NOTE 2: Airbus Industrie Service Bulletin A320-29-1061, dated April 13, 1993, references Dowty Aerospace Service Bulletin 600-29-171, dated January 4, 1993, which provides specific descriptions of the discrepancies in paragraph 2 of that service bulletin.

NOTE 3: The discrepancies that are addressed in this AD can only occur during use of the RAT, and not during stowage of the RAT; therefore, it is not necessary to perform the repetitive inspections and end-float checks before each functional ground check of the RAT if the RAT has not been used since the preceding inspection.

(c) If any discrepancy is detected as a result of any detailed visual inspection required by this AD, prior to further flight, accomplish the requirements of either paragraph (c)(1) or (c)(2) of this AD.

(1) Replace the RAT in accordance with Airbus Industrie Service Bulletin A320-29-1061, dated April 13, 1993; and after replacement, repeat the detailed visual inspection and the end-float check required by paragraph (a) of this AD. Thereafter, repeat the detailed visual inspection and the end-float check after each functional ground check of the RAT, and after each in-flight deployment of the RAT. Or

(2) Install a new modified RAT (Modification 24701) in accordance with Airbus Service Bulletin A320-29-1065, dated February 28, 1995. Installation of this modification constitutes terminating action for the repetitive visual inspections and end-float checks required by this AD.

(d) Within 2 years after the effective date of this AD, install a new modified RAT (Modification 24701) in accordance with Airbus Service Bulletin A320-29-1065, dated February 28, 1995. Installation of this modification constitutes terminating action for the repetitive visual inspections and end-float checks required by this AD.

(e) 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.

(f) 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.

(g) The actions shall be done in accordance with Airbus Industrie Service Bulletin A320-29-1061, dated April 13, 1993, and Airbus Service Bulletin A320-29-1065, dated February 28, 1995. The incorporation by reference of Airbus Service Bulletin A320-29-1065, dated February 28, 1995, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The incorporation by reference of Airbus Industrie Service Bulletin A320-29-1061, dated April 13, 1993, was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of March 3, 1994 (59 FR 4562, February 1, 1994). 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.

(h) This amendment becomes effective on January 27, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 94-01-11, amendment 39-8793 (59 FR 4562, February 1, 1994), which is applicable to certain Airbus Model A320 series airplanes, was published in the Federal Register on September 11, 1996 (61 FR 47829). The action proposes to continue to require repetitive visual inspections and end-float checks of the ram air turbine (RAT), and replacement of the RAT, if necessary. The action also proposed to require the installation of the new modified RAT (Modification 24701) as terminating action for the repetitive inspections. In addition, the action proposed to limit the applicability of the AD to only airplanes on which Modification 24701 has not been installed.

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

Both commenters support the proposed rule.

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 as proposed.

Cost Impact
There are approximately 94 Airbus Model A320 series airplanes of U.S. registry that will be affected by this AD.

The inspections/checks that are currently required by AD 94-01-11 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 of the current inspection/check requirement is estimated to be $5,640, or $60 per airplane, per inspection/check.

The terminating modification that is required in this AD action will take approximately 74 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to operators. Based on these figures, the cost impact on U.S. operators of the modification requirement of this AD is estimated to be $417,360, or $4,440 per airplane.

The 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.

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 U.S.C. 106(g), 40113, 44701.
39.13 - [Amended]
2. Section 39.13 is amended by removing amendment 39-8793 (59 FR 4562, February 1, 1994), and by adding a new airworthiness directive (AD), amendment 39-9849, to read as follows: