AD 98-06-10 ACTIVE

This amendment adopts a new airworthiness directive (AD), applicable to all Israel Aircraft Industries, Ltd., Model 1121, 1121A, 1121B, 1123, 1124, 1124A, 1125 Westwind Astra, and Astra SPX series airplanes, that requires repetitive functional tests for proper operation of hydraulic fuses installed in the brake system and emergency hydraulic indicating system; and replacement of any discrepant hydraulic fuse with a new, improved unit. This amendment is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the hydraulic fuse to operate properly, due to internal corrosion, in the event of an external leak downstream of the fuse, which could result in loss of hydraulic systems.

Final rule

98-06-10 ISRAEL AIRCRAFT INDUSTRIES, LTD.: Amendment 39-10387. Docket 97-NM- 169-AD.

Applicability: All Model 1121, 1121A, 1121B, 1123, 1124, 1124A, 1125 Westwind Astra, and Astra SPX 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 (e) 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 failure of the hydraulic fuse to operate properly in the event of an external leak downstream of the fuse, which could result in loss of hydraulic systems, accomplish the following:

(a) For Model 1121, 1121A, 1123, 1124, and 1124A series airplanes: Perform a functional test (by measuring fluid loss) for proper operation of the hydraulic fuses installed in the brake system and emergency hydraulic indicating system in accordance with Commodore Jet Service Bulletin 1121-29-022 (for Model 1121, 1121A, and 1121B series airplanes), Westwind Service Bulletin SB 1123-29-045 (for Model 1123 series airplanes), or Westwind Service Bulletin SB 1124- 29-132 (for Model 1124 and 1124A series airplanes); all dated September 11, 1996; as applicable; at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD. Thereafter, repeat the inspections at intervals not to exceed 1,200 flight hours or 3 years, whichever occurs first.

(1) Within 250 flight hours or 1 year after the effective date of this AD, whichever occurs first. Or,

(2) Prior to accumulation of 1,200 total flight hours, or within 3 years since the date of manufacture, whichever occurs first.

(b) For Model 1125 Westwind Astra and Astra SPX series airplanes: Perform a functional test (by measuring fluid loss) for proper operation of the hydraulic fuses installed in the brake system, in accordance with Astra Service Bulletin 1125-32-154, dated September 11, 1996, at the later of the times specified in paragraphs (b)(1) and (b)(2) of this AD. Thereafter, repeat the inspections at intervals not to exceed 1,000 flight hours or 3 years, whichever occurs first.

(1) Within 250 total flight hours or 1 year after the effective date of this AD, whichever occurs first. Or,

(2) Prior to the accumulation of 1,000 total flight hours, or within 3 years since the date of manufacture, whichever occurs first.

(c) If, during any inspection required by paragraph (a) or (b) of this AD, any discrepancy is found, prior to further flight, replace the fuse with a new, improved fuse (part number 713047 with suffix "A" after the serial number), in accordance with Commodore Jet Service Bulletin SB 1121-29-022 (for Model 1121, 1121A, and 1121B series airplanes), Westwind Service Bulletin SB 1123-29-045 (for Model 1123 series airplanes), Westwind Service Bulletin SB 1124-29-132 (for Model 1124 and 1124A series airplanes), or Astra Service Bulletin SB 1125-32-154 (for Model 1125 Westwind Astra and Astra SPX series airplanes); all dated September 11, 1996; as applicable.

NOTE 2: Replacement of the fuse in accordance with paragraph (c) of this AD does not constitute terminating action for the repetitive functional tests required by paragraphs (a) and (b) of this AD.

(d) As of the effective date of this AD, no person shall install on any airplane a hydraulic fuse having part number 713047, unlessit has a suffix "A" after the serial number.

(e) 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(f) 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.

(g) The actions shall be done in accordance with Commodore Jet Service Bulletin SB 1121-29-022, dated September 11, 1996; Westwind Service Bulletin SB 1123-29-045, dated September 11, 1996; Westwind Service Bulletin SB 1124-29-132, dated September 11, 1996; and Astra Service Bulletin SB 1125-32-154, dated September 11, 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 Galaxy Aerospace Corporation, One Galaxy Way, Fort Worth Alliance Airport, Fort Worth, Texas 76177. 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 4: The subject of this AD is addressed in Israeli airworthiness directive 29-97-03-10, dated March 27, 1997.

(h) This amendment becomes effective on April 17, 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 Israel Aircraft Industries, Ltd., Model 1121, 1121A, 1121B, 1123, 1124, 1124A, 1125 Westwind Astra, and Astra SPX series airplanes was published in the Federal Register on January 13, 1998 (63 FR 1930). That action proposed to require repetitive functional tests for proper operation of hydraulic fuses installed in the brake system and emergency hydraulic indicating system; and replacement of any discrepant hydraulic fuse with a new, improved unit.

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.

Interim Action
This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.

Cost Impact
The FAA estimates that 359 airplanes of U.S. registry will be affected by this AD, that it will take approximately 2 work hours per airplane to accomplish the required functional test, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $43,080, or $120 per airplane, per functional test.

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:

The service information referenced in this AD may be obtained from Galaxy Aerospace Corporation, One Galaxy Way, Fort Worth Alliance Airport, Fort Worth, Texas 76177. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.