Airworthiness Directives; de Havilland Model DHC-8-102, -103, and -301 Series Airplanes

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 96-NM-58-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules Docket No.

96-NM-58-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

Transport Canada Aviation, which is the airworthiness authority for Canada, recently notified the FAA that an unsafe condition may exist on certain de Havilland Model DHC-8-102, -103, and -301 series airplanes. Transport Canada Aviation advises that it received reports indicating that chafing of the electrical wiring was found at several locations of the cabin ceiling lighting system on Model DHC-8 series airplanes. The cause of this chafing has been attributed to the routing of the cables; this routing allowed the cables to come in contact with the cabin interior valence panels. Chafing of the electrical wiring of the cabin ceiling lighting system can cause the wires on the aircraft structure to short circuit, overheat, and smoke. This condition, if not corrected, could result in the possibility of fire on the airplane.

Explanation of Relevant Service Information

Bombardier has issued Service Bulletin S.B. 8-33-35, dated September 1, 1995, which describes procedures for a one-time inspection for wear and breakage of wire segments of the individual lighting units of the ceiling and sidewall lights, and replacement of any damaged wiring. The service bulletin also describes procedures for installation of teflon spiral wrap on the wiring of the ceiling and sidewall lights (Modification 8/2158). Transport Canada Aviation classified this service bulletin as mandatory and issued Canadian airworthiness directive CF-95-18, dated December 15, 1996, in order to assure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

These airplane models are manufactured in Canada and are 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, Transport Canada Aviation has kept the FAA informed of the situation described above. The FAA has examined the findings of Transport Canada Aviation, 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.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, the proposed AD would require a one-time inspection for wear and breakage of wire segments of the individual lighting units of the ceiling and sidewall lights, and replacement of any damaged wiring. The proposed AD also would require installation of teflon spiral wrap on the wiring of the ceiling and sidewall lights. The actions would be required to be accomplished in accordance with the service bulletin described previously.

Cost Impact

The FAA estimates that 73 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 30 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $250 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $149,650, or $2,050 per airplane. The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed 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 proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

de Havilland, Inc.: Docket 96-NM-58-AD.

Applicability: Model DHC-8-102, -103, and -301 series airplanes; serial numbers 002 though 010 inclusive, 012 through 201 inclusive, 203 through 209 inclusive, 211 through 215 inclusive, 217 through 220 inclusive, 222, and 223; on which de Havilland Modification 8/ 1114 or 8/1110 (reference de Havilland Service Bulletin S.B. 8-33- 35) has not been accomplished; 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 (b) 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 possibility of a fire on an airplane due to chafing of the electrical wiring of the cabin ceiling lighting system, accomplish the following: (a) Within 1,000 hours time-in-service or 6 months after the effective date of this AD, whichever occurs first: Accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD in accordance with de Havilland Service Bulletin S.B. 8-33-35, dated September 1, 1995. (1) Perform a one-time inspection for wear and breakage of wire segments of the individual lighting units of the ceiling and sidewall lights. Prior to further flight, replace any damaged wiring.

(2) Install teflon spiral wrap on the wiring of the ceiling and sidewall lights (Modification 8/2158). (b) 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, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

(c) 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.

Issued in Renton, Washington, on September 6, 1996. James V. Devany, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 96-23443 Filed 9-12-96; 8:45 am] BILLING CODE 4910-13-U