AD 98-06-01

This amendment adopts a new airworthiness directive (AD), applicable to all Dassault Model Mystere-Falcon 50 series airplanes, that requires a one-time inspection of the clearances around the wiring harnesses of the right-hand electrical cabinet, and readjustment of the clearances, if necessary. This amendment will also require installation of protective strips on the wiring harnesses and equipment supports. This amendment is prompted by issuance of mandatory continued airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent interference between the wiring harnesses and adjacent equipment, support brackets, and structural elements, which could cause an electrical short circuit resulting in fire, and consequent loss of electrical power to essential flight systems.

Final rule

98-06-01 DASSAULT AVIATION: Amendment 39-10379. Docket 97-NM-190-AD.
Applicability: All Model Mystere-Falcon 50 series airplanes, 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 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 interference between the wiring harnesses and adjacent equipment, support brackets, and structural elements, which could cause an electrical short circuit resulting in fire, and consequent loss of electrical power to essential flight systems; accomplish the following:

(a) Within 6 months or 300 flight hours after the effective date of this AD, whichever occurs first, accomplish the requirements of paragraphs (a)(1), (a)(2), and (a)(3) of this AD in accordance with Dassault Service Bulletin F50-256 (F50-20-5), Revision 1, dated December 22, 1996.

(1) Perform a one-time inspection of the clearances between the wiring harnesses and the adjacent equipment, support brackets, and structural elements. If any clearance is outside the limits specified in the service bulletin, prior to further flight, readjust the clearances in accordance with the service bulletin.

(2) Install Teflon protective strips on the wiring harnesses in the vicinity of the equipment supports.

(3) Install rubber protective strips to the rear edges of the equipment supports.

(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, International Branch, ANM-116, 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, International Branch, ANM-116.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(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.

(d) The actions shall be done in accordance with Dassault Service Bulletin F50-256 (F50-20- 5), Revision 1, dated December 22, 1996. 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 Dassault Falcon Jet Corporation, Teterboro Airport, P.O. Box 2000, South Hackensack, New Jersey 07606. 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.

NOTE 3: The subject of this AD is addressed in French airworthiness directive 96-094-017(B)R1, dated December 18, 1996.

(e) This amendment becomes effective on April 15, 1998.

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 all Dassault Model Mystere-Falcon 50 series airplanes was published in the Federal Register on December 11, 1997 (62 FR 65230). That action proposed to require a one-time inspection of the clearances around the wiring harnesses of the right-hand electrical cabinet, and readjustment of the clearances, if necessary. That action also proposed to require installation of protective strips on the wiring harnesses and equipment supports.

Comments
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.

Conclusion
The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
The FAA estimates that 155 Dassault Model Mystere-Falcon 50 series airplanes of U.S. registry will be affected by this AD, that it will take approximately 6 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $355 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $110,825, or $715 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.

Regulatory Impact
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 U.S.C. 106(g), 40113, 44701.

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