AD 2000-07-25

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Gulfstream Model G-IV series airplanes. This action requires modification of the power feeder cable assemblies of the left and right engine alternators. This amendment is prompted by an incident of an in-flight engine fire on a Model G-IV series airplane due to chafing of the power feeder cable assembly of an engine alternator. The actions specified in this AD are intended to prevent interference and chafing between the alternator power feeder cables and adjacent structure, which could result in an electrical short circuit and consequent fire ignition source in the engine compartment.

Final rule; request for comments

2000-07-25 GULFSTREAM AEROSPACE CORPORATION: Amendment 39-11680. Docket 2000-NM-82-AD.

Applicability: Model G-IV series airplanes, serial numbers 1000 through 1404 inclusive; 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 and chafing between the alternator power feeder cables and adjacent structure, which could result in an electrical short circuit and consequent fire ignition source in the engine compartment, accomplish the following:

Modification

(a) Within 150 total flight hours after the effective date of this AD, accomplish paragraphs (a)(1) or (a)(2) of this AD, as applicable, in accordance with Gulfstream IV Customer Bulletin No. 112, dated February 15, 2000, and Gulfstream IV Aircraft Service Change No. 410, dated February 11, 2000.

(1) For airplanes having serial numbers 1000 through 1384 inclusive: Accomplish paragraphs (a)(1)(i) and (a)(1)(ii) of this AD for the left and right engines, in accordance with Paragraphs B. and C. of the Modification Instructions of the aircraft service change.

(i) Replace the alternator power feeder cables with new cables, and reroute the cables.

(ii) Install additional bracketsand clamps.

NOTE 2: On some airplanes, some of the actions described in the aircraft service change were accomplished prior to the effective date of this AD. On these airplanes, these actions are not required to be repeated, as allowed by the phrase, "unless accomplished previously." However, any action described in the aircraft service change that has not been accomplished on these airplanes must be accomplished in accordance with this paragraph.

(2) For airplanes having serial numbers 1385 through 1404 inclusive: Accomplish paragraphs (a)(2)(i) and (a)(2)(ii) on the right engine in accordance with paragraph D. of the Modification Instructions of the aircraft service change.

(i) Install a bracket and spacer.

(ii) Reroute the alternator power feeder cables.

Alternative Methods of Compliance

(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, Atlanta Aircraft Certification Office (ACO), FAA, Small 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, Atlanta ACO.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

Special Flight Permits

(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.

Incorporation by Reference

(d) The actions shall be done in accordance with Gulfstream IV Customer Bulletin No. 112, dated February 15, 2000; and Gulfstream IV Aircraft Service Change No. 410, dated February 11, 2000, as applicable. (NOTE: The issue date of Gulfstream IV Aircraft Service Change No. 410 is indicated only on the cover page of the document; no other page of this document is dated.)

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, M/S D-10, Savannah, Georgia 31402-9980. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, Atlanta Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on May 1, 2000.

The FAA has received a report indicating that an in-flight engine fire occurred on a Gulfstream Model G-IV series airplane. Inspection revealed that the fire was contained within the engine nacelle. Further investigation indicated the ignition source of the fire to be an alternator power feeder cable chafing against the Approach Idle Solenoid fuel line. Such chafing, if not corrected, could result in an electrical short circuit that could spark and ignite a fire in the engine compartment.

Explanation of Relevant Service Information
The FAA has reviewed and approved Gulfstream IV Customer Bulletin No. 112, dated February 15, 2000, and Gulfstream IV Aircraft Service Change No. 410, dated February 11, 2000. The customer bulletin references the aircraft service change, which describes procedures for modification of the power feeder cable assemblies of the left and right engine alternators. Modification procedures include replacing the cables, rerouting the cables to ensure adequate clearance between the cables and adjacent structure, and ensuring that the cables are properly connected to the terminals and that torque values are within specified limits. Procedures also include installing additional brackets and clamps to secure the cables and eliminate slack in the cables.

Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on other Gulfstream Model G-IV series airplanes of the same type design, this AD is being issued to prevent interference and chafing between the alternator feeder cables and adjacent structure, which could result in an electrical short circuit and consequent fire ignition source in the engine compartment. This AD requires modifying the power feeder cable assemblies of the left and right engine alternators. The actions are required to be accomplished in accordance with the service information described previously.

Determinationof Rule's Effective Date
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter'sideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2000-NM-82-AD." The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided underthe 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: