AD 94-01-13

This amendment adopts a new airworthiness directive (AD), applicable to certain de Havilland Model DHC-8-300 series airplanes, that requires modifying the airplane fire detection system and revising the Airplane Flight Manual (AFM) to include procedures related to operating the system. This amendment is prompted by reports of several oil fires in the inter compressor case (ICC) assembly. The actions specified by this AD are intended to prevent severe structural damage to the airplane due to an internal engine fire within the ICC.

Final Rule

94-01-13 DE HAVILLAND, INC.: Amendment 39-8795. Docket 93-NM-116-AD.

Applicability: Model DHC-8-301, -311, and -314 series airplanes, serial numbers 100 through 332 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent severe structural damage to the airplane due to an internal engine fire within the inter compressor case, accomplish the following:

(a) Within 90 days after the effective date of this AD, accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD:

(1) Install an inter compressor case (ICC) fire detection system in accordance with de Havilland Service Bulletin S.B. 8-26-14, dated March 6, 1992.

(2) Connect the ICC fire detection system to the airplane fire detection system in accordance with de Havilland Service Bulletin S.B. 8-26-14, dated March 6, 1992.

(3) Revise Section 4, "Abnormal Procedures", Page 4-10-1, of the FAA-approved Airplane Flight Manual (AFM), by adding the following steps immediately after step 1 of paragraph 4-10, "ENGINE FIRE DETECTION SYSTEM FAILURES". This may be accomplished by inserting a copy of this AD in the AFM.

"For aircraft incorporating de Havilland Modification 8/1835

2. FAULT A advisory light illuminates - Land as soon as practicable."

(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: 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 FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The installation and connection shall be done in accordance with de Havilland Service Bulletin S.B. 8-26-14, dated March 6, 1992. 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 de Havilland, Inc., Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) 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 certain de Havilland Model DHC-8-300 series airplanes was published in the Federal Register on September 29, 1993 (58 FR 50868). That action proposed to require the installation of an inter compressor case (ICC) fire detection system, connection of the ICC fire detection system to the airplane fire detection system, and a revision to the AFM to provide the flight crew with operating procedures associated with the ICC fire detection system.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

The FAA estimates that 19 airplanes of U.S. registry will be affected by this AD, that it will take approximately 9 work hours per airplane to accomplish the required actions, and that the average labor rate is $55 per work hour. Required parts will cost approximately $985 per airplane. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $28,120, or $1,480 per airplane. 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: