AD 2004-07-21

This amendment adopts a new airworthiness directive (AD), applicable to certain Model Astra SPX and 1125 Westwind Astra series airplanes, that requires detailed inspections and resistance measurements of the starter generator electrical cables of both engines to detect damage, and replacement of the electrical cable and cable support if any damage is found. This amendment also requires eventual replacement of the cable support. This action is necessary to prevent chafing of the starter generator cable, which could result in electrical arcing in the vicinity of a fuel line, and possible fire or explosion. This action is intended to address the identified unsafe condition.

Final rule.

2004-07-21 Gulfstream Aerospace LP (Formerly Israel Aircraft Industries, Ltd.): Amendment 39-13565. Docket 2002-NM-236-AD.

Applicability: Model Astra SPX and 1125 Westwind Astra series airplanes, serial numbers 004 through 141 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent chafing of the starter generator cable, which could result in electrical arcing in the vicinity of a fuel line, and possible fire or explosion, accomplish the following:

Service Bulletin Reference

(a) The following information pertains to the service bulletin referenced in this AD:

(1) The term "service bulletin," as used in this AD, means the Accomplishment Instructions of Gulfstream 1125 Astra and Astra SPX Service Bulletin 100-54-252, dated April 24, 2002.

(2) Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include such a requirement.

Initial and Repetitive Inspections

(b) Within 250 flight hours after the effective date of this AD, perform a detailed inspection of the starter generator electrical cables of both engines to detect damage, per the service bulletin.

Note 1: For the purposes of this AD, a detailed inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required."

Follow-On Action if No Damage Is Found

(c) If no damage is found during any inspection required by paragraph (b) of this AD: Before further flight, measure the insulation resistance between the starter generator cable and firewall support in accordance with the service bulletin.

(1) If the measured resistance is less than 20 megaohms: Before further flight, replace the electrical cables and cable support per paragraph (d) of this AD.

(2) If the measured resistance is greater than or equal to 20 megaohms, repeat the inspection required by paragraph (b) of this AD at intervals not to exceed 250 flight hours, including the follow-on measurement in paragraph (c), as applicable, until the applicable replacement required by paragraph (d) or (e) of this AD is accomplished.

Replacement if Any Damage Is Found

(d) If any damage is found during any inspection required by paragraph (b), or if the insulation resistance as required to be measured by paragraph (c) of this AD is less than 20 megaohms: Before further flight, replace the electrical cables and cable support per Part C of the service bulletin. This replacement terminates the repetitive inspections required by paragraph (b) and the measurement required by paragraph (c) of this AD, for that affected engine.

Replacement if No Damage Is Found

(e) If no damage is found during any inspection required by paragraph (b), or if the insulation resistance as required to be measured by paragraph (c) of this AD is greater than or equal to 20 megaohms: Within 5 years after the effective date of this AD, or at the next engine removal, whichever comes first, replace the cable support per Part B of the service bulletin. This replacement terminates the repetitive inspections required by paragraph (b) and the measurement required by paragraph (c) of this AD, for that affected engine.

Alternative Methods of Compliance

(f) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, is authorized to approve alternative methods of compliance for this AD.

Incorporation by Reference

(g) The actions shall be done in accordance with Gulfstream 1125 Astra and Astra SPX Service Bulletin 100-54-252, dated April 24, 2002. 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 Gulfstream Aerospace Corporation, P.O. Box 2206, Mail Station D25, Savannah, Georgia 31402. 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 2: The subject of this AD is addressed in Israeli airworthiness directive 54-02-06-12, dated July 4, 2002.

Effective Date

(h) This amendment becomes effective on May 11, 2004.

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 Model Astra SPX and 1125 Westwind Astra series airplanes was published in the Federal Register on January 7, 2004 (69 FR 895). That action proposed to require detailed inspections and resistance measurements of the starter generator electrical cables of both engines to detect damage, and replacement of the electrical cable and cable support if any damage is found. That action also proposed to require eventual replacement of the cable support.

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 ImpactThe FAA estimates that 55 airplanes of U.S. registry will be affected by this AD, that it will take approximately 2 work hours per airplane to accomplish the inspection and measurement; 4 hours per airplane to accomplish the replacement of the cable support if no damage is found; and 12 hours per airplane to accomplish the replacement of the cable and cable support if any damage is found. The average labor rate is $65 per work hour. All necessary parts will be provided by the manufacturer free of charge. Based on these figures, the cost impact of the proposed inspection and measurement on U.S. operators is estimated to be $7,150, or $130 per airplane, per inspection cycle. For airplanes on which no damage is found, the cost impact of the proposed replacement on U.S. operators is estimated to be $14,300, or $260 per airplane. For airplanes on which damage is found, the cost impact of the proposed replacement on U.S. operators is estimated to be $42,900, or $780 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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: