AD 94-01-11

This amendment adopts a new airworthiness directive (AD), applicable to Airbus Model A320 series airplanes, that requires visual inspections and end-float checks of the ram air turbine (RAT), and replacement of the RAT, if necessary. This amendment is prompted by a report that, during an on-ground functional test of the RAT, the RAT broke away from its support leg. 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.

94-01-11 AIRBUS INDUSTRIE: Amendment 39-8793. Docket 93-NM-119-AD.

Applicability: Model A320 series airplanes, equipped with ram air turbine (RAT) part number 680203019, 680203020, 680203021, or 680203027; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the 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 the effective date of this AD; or

(2) Before and after the first functional ground check of the RAT that is performed after the effective date of this AD; or(3) After the first in-flight deployment of the RAT that occurs after the effective date of this AD.

(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 1: 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 2: 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 paragraph (c)(1) and (c)(2) of this AD.

(1) Replace the RAT in accordance with Airbus Industrie Service Bulletin A320-29-1061, dated April 13, 1993; and

(2) 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.

(d) 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(f) The inspections, checks, and replacement shall be done in accordance with Airbus Industrie Service Bulletin A320-29-1061, dated April 13, 1993. 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.

(g) This amendment becomes effective on March 3, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to Airbus Model A320 series airplanes was published in the Federal Register on October 5, 1993 (58 FR 51793). That action proposed to require detailed visual inspections and end-float checks of the RAT, and replacement of the RAT with a new RAT, if necessary.

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

All of the commenters support the proposal.

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.

The FAA estimates that 74 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the requiredinspections and checks, and that the average labor rate is $55 per work hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $4,070, or $55 per airplane, per inspection/check. This total cost figure assumes that no operator has yet accomplished the requirements of this AD.

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 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: