AD 97-10-06

This amendment adopts a new airworthiness directive (AD), applicable to certain IAI Model 1125 Westwind Astra series airplanes, that requires repetitive inspections to detect loose or damaged rivets that fasten a certain support beam to the frame of the fuselage; and modification of the attachment between the support beam and fuselage by installation of additional fasteners, if necessary. This amendment also will require the eventual accomplishment of this modification on all airplanes, which will terminate the repetitive inspections. This amendment is prompted by reports indicating that the attachment between this beam and the fuselage has become loose on several airplanes. Movement of this beam could restrict the movement of the elevator and rudder controls that run through the bellcranks attached to it. The actions specified by this AD are intended to prevent movement of this beam, which could restrict movement of the elevator and rudder controls, and consequently leadto reduced controllability of the airplane.

Final rule

97-10-06 ISRAEL AIRCRAFT INDUSTRIES (IAI), LTD.: Amendment 39-10018. Docket 96-NM- 96-AD.

Applicability: Model 1125 Westwind Astra series airplanes, as listed in IAI Service Bulletin SB 1125-53-135, dated April 26, 1995; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (c) 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 movement of the support beam attached to the fuselage frame at station 452.00, which could restrict movement of the elevator and rudder controls, and consequently lead to reduced controllability of the airplane, accomplish the following:

(a) Within 50 hours time-in-service after the effective date of this AD, conduct a visual inspection to detect loose or damaged ("fretted") rivets that fasten the support beam to the fuselage frame at station 452.000, in accordance with Part A of IAI Service Bulletin SB 1125-53-135, dated April 26, 1995.

(1) If no loose or fretted rivet is detected, repeat this inspection thereafter at intervals not to exceed 250 hours time-in-service until the modification required by paragraph (b) of this AD is accomplished.

(2) If any loose or fretted rivet is detected, prior to further flight, modify the support beam in accordance with Part B of IAIService Bulletin SB 1125-53-135, dated April 26, 1995. After this modification is accomplished, no further action is required by paragraph (a) or (b) of this AD.

(b) Within 500 hours time-in-service after the effective date of this AD, modify the support beam in accordance with Part B of IAI Service Bulletin SB 1125-53-135, dated April 26, 1995. Accomplishment of this modification constitutes terminating action for the repetitive inspections required by paragraph (a)(1) of this AD.

(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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113.

NOTE 2: Information concerning the existence of approved alternative methods ofcompliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(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 inspections and modification shall be done in accordance with IAI Service Bulletin SB 1125-53-135, dated April 26, 1995. 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 Technical Publications, Astra Jet Corporation, 77 McCullough Drive, Suite 11, New Castle, Delaware 19720. 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.

(f) This amendment becomes effective on June 16, 1997.

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 Israel Aircraft Industries (IAI), Ltd. Model 1125 Westwind Astra series airplanes was published in the Federal Register on February 19, 1997 (62 FR 7385). That action proposed to require repetitive visual inspections to detect loose or fretted rivets that fasten the support beam to the fuselage frame at station 452.00. Should any loose or fretted rivet be detected, that action proposed to require modification of the attachment between the beam and the fuselage by the installation of additional fasteners. Additionally, that action proposed to require that this modification be installed eventually on all affected airplanes.

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 58 IAI Model 1125 Westwind Astra series airplanes of U.S. registry will be affected by this AD.

It will take approximately 1 work hour per airplane to accomplish the required visual inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the required inspection on U.S. operators is estimated to be $3,480, or $60 per airplane, per inspection.

It will take approximately 8 work hours per airplane to accomplish the required terminating modification, at an average labor rate of $60 per work hour. The cost of parts is minimal. Based on these figures, the cost impact of the required modification on U.S. operators is estimated to be $27,840, or $480 per airplane.

The cost impact figures discussed above are 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: