AD 96-03-09

This amendment adopts a new airworthiness directive (AD), applicable to certain de Havilland Model DHC-8 series airplanes, that requires modification of a certain battery temperature monitor. This amendment is prompted by reports of failure of the battery temperature monitor, which resulted in smoke in the flight compartment. The actions specified by this AD are intended to prevent failure of the battery monitor, which could result in smoke in the flight compartment.

Final rule

96-03-09 DE HAVILLAND, INC.: Amendment 39-9506. Docket 95-NM-12-AD.
Applicability: Model DHC-8-102, -103, -106, -301, -311, -314, and -315 series airplanes, serial numbers 003 through 389 inclusive; equipped with Ametek/Weston battery temperature monitor having part number (P/N) 522487; 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 use the authority provided in paragraph (c) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request shouldinclude an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the battery temperature monitor, which could result in smoke in the flight compartment, accomplish the following:

(a) Within 6 months after the effective date of this AD, modify the battery temperature monitor in accordance with de Havilland Service Bulletin S.B. 8-24-53, dated September 7, 1994.

(b) As of the effective date of this AD, no person shall install an Ametek/Weston battery temperature monitor, P/N 522487, on any airplane.

(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, 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.

(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 modification shall be done in accordance with de Havilland Service Bulletin S.B. 8-24-53, dated September 7, 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 Bombardier, Inc., Bombardier Regional Aircraft Division, Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, Engine and Propeller Directorate, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on March 4, 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 de Havilland Model DHC-8 series airplanes was published in the Federal Register on February 21, 1995 (60 FR 9647). That action proposed to require modification of a certain battery temperature monitor.

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

The commenter supports the proposed rule.

Since issuance of the NPRM, Transport Canada Aviation has issued Canadian airworthiness directive CF-94-22R1, dated June 30, 1995, which revises the effectivity of the original version of the Canadian airworthiness directive by adding Model DHC-8-315 series airplanes.

The FAA has revised the applicability of the final rule to include these additional airplanes. These additional airplanes currently are operated by non-U.S. operators under foreign registry; therefore, they are not affected directly by this AD action. However, the FAA considers that the revision to the applicability of the rule is necessary to ensure that the unsafe condition is addressed in the event that these subject airplanes are imported and placed on the U.S. Register in the future.

After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 137 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. The cost of required parts will benominal. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $8,220, or $60 per airplane.

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.

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 addingthe following new airworthiness directive: