AD 94-15-10

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Aerospatiale Model ATR42-300 and -320 series airplanes. This action requires an inspection to verify that the cables supplying power to the aileron trim are adequately protected and to detect any damage to these cables. This amendment also requires installation of protective sleeves on unprotected cables, and replacement of damaged cables. This amendment is prompted by reports of a short circuit of these cables due to worn protective sleeves. The actions specified in this AD are intended to prevent short circuiting of the cables that supply power to the aileron trim, which could lead to loss of aileron trim control.

Final rule; request for comments.

94-15-10 AEROSPATIALE: Amendment 39-8981. Docket 94-NM-99-AD.

Applicability: Model ATR42-300 and -320 series airplanes having manufacturer's serial numbers 003 through 072, inclusive, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent loss of aileron trim control due to short circuiting of the cables that supply power to the aileron trim, accomplish the following:

(a) Within 90 days after the effective date of this AD, perform a visual inspection to verify that the cables, which supply power to the aileron trim, are adequately protected, in accordance with Avions de Transport Regional Service Bulletin ATR42-27-0070, dated December 20, 1993.

(b) If the cables are adequately protected, no further action is required by this AD.

(c) If any cable is not adequately protected, prior to further flight, perform a visual inspection to detect damage to the unprotected cable, in accordance with Avions de Transport Regional Service Bulletin ATR42-27-0070, dated December 20, 1993.

(1) For any undamaged cable: Within 90 days after the effective date of this AD, install protective sleeves (Modification A0014) on the undamaged, unprotected cable, in accordance with Avions de Transport Regional Service Bulletin ATR42-27-0014, Revision 2, dated December 20, 1993.

(2) For any damaged cable: Prior to further flight, replace the damaged cable in accordance with Avions de Transport Regional Service Bulletin ATR42-27-0070, dated December 20, 1993, with cabling that has been previously modified (Modification A0014) in accordance with Avions de Transport Regional Service Bulletin ATR42-27-0014, Revision 2, dated December 20, 1993.

(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: 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 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.

(f) The inspection and replacement shall be done in accordance with Avions de Transport Regional Service Bulletin ATR42-27-0070, dated December 20, 1993. The installation shall be done in accordance with Avions de transport Regional Service Bulletin ATR42-27-0014, Revision 2, dated December 20, 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 Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, 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 August 11, 1994.

The Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, recently notified the FAA that an unsafe condition may exist on certain Aerospatiale Model ATR42-300 and -320 series airplanes. The DGAC advises that the cables that supply power to the aileron trim short-circuited on an in-service airplane. Investigation revealed that the protective sleeve on these cables was worn. Short circuiting of the cables that supply power to the aileron trim, if not corrected, could result in loss of aileron trim control.

Avions de Transport Regional has issued Service Bulletin ATR42-27-0070, dated December 20, 1993, which describes procedures for visually inspecting to verify that the protective sleeve on the cables that supply power to the aileron trim adequately protect the cables, and to detect damaged cables. This service bulletin also contains instructions for replacing damaged cables with cables that have been modified inaccordance with Avions de Transport Regional Service Bulletin ATR42-27-0014, Revision 2, dated December 20, 1993. This latter service bulletin describes procedures for installation of protective sleeves (Modification A0014) on cables that are not adequately protected. The DGAC classified these service bulletins as mandatory and issued French Airworthiness Directive 94-004-054(B), dated January 5, 1994, in order to assure the continued airworthiness of these airplanes in France.

This airplane model is manufactured in France and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD is being issued to prevent loss of aileron trim control due to a short circuit in the cables that supply power to the aileron trim. This AD requires visually inspecting to verify that the cables that supply power to the aileron trim are adequately protected, and to detect damaged cables; replacing damaged cables with cables that have been previously modified; and installing protective sleeves on unprotected cables. The actions are required to be accomplished in accordance with the service bulletins described previously.

This AD applies only to airplanes having manufacturer's serial numbers 003 through 072. For airplanes having manufacturer's serial numbers 073 and subsequent, a glass fabric adhesive tape has been applied to the cables prior todelivery of the airplane; therefore, these airplanes are not subject to the unsafe condition addressed by this AD action.

Since 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.

Comments Invited
Although 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 beamended 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.

Comments 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.

Commenters 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 94-NM-99-AD." The postcard will be date stamped and returned to the commenter.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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it 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."

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. 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: