AD 95-08-02

This amendment adopts a new airworthiness directive (AD), applicable to certain Jetstream Model 4101 airplanes, that requires installation of new case drain pipes and an additional fairlead support for the hydraulics case drain line in the rear spar area of the engine/nacelle. This amendment is prompted by reports of fatigue failure of the case drain line in the hydraulics system. The actions specified by the proposed AD are intended to prevent the loss of main system hydraulics as a result of lack of support against vibration and subsequent fatigue failure of the case drain line for the hydraulics system.

Final rule

95-08-02 JETSTREAM AIRCRAFT LIMITED: Amendment 39-9191. Docket 94-NM-170-AD.
Applicability: Model 4101 airplanes; constructors numbers 41005 through 41015 inclusive, 41019 through 41024 inclusive, 41028, and 41029; 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 (b) 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 should include 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 the loss of the main system hydraulics, accomplish the following:

(a) Within 4 months after the effective date of this AD, install new case drain pipes and an additional fairlead support for the hydraulics case drain line in the rear spar area of the engine/nacelle in accordance with Jetstream Service Bulletin J41-29-005, Revision 1, dated August 12, 1994; or Revision 2, dated August 30, 1994.

(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, Standardization Branch, FAA, Transport Airplane Directorate, ANM-113. 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(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 installation shall be done in accordance with the following Jetstream service bulletins, as applicable, which contain the specified effective pages:

Service Bulletin Referenced and Date
Page Number
Revision Level Shown on Page
Date Shown on Page
J41-29-005
Revision 2
August 30, 1994
1, 4

2, 3, 5-12
2

1
August 30, 1994

August 12, 1994

J41-29-005
Revision 1
August 12, 1994
1-12
1
August 12, 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 Jetstream Aircraft, Inc., P.O. Box 16029, Dulles International Airport, Washington, DC 20041-6029. 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.

(e) This amendment becomes effective on May 10, 1995.

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 Jetstream Model 4101 airplanes series airplanes was published in the Federal Register on December 16, 1994 (59 FR 64875). That action proposed to require installation of new case drain pipes and an additional fairlead support for the hydraulics case drain line in the rear spar area of the engine/nacelle.

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.

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 as proposed.

The FAA estimates that 9 airplanes of U.S. registry will be affected by this AD, that it willtake approximately 10 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be supplied by the manufacturer at no cost to operators. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $5,400, or $600 per airplane.

The total 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 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: