We have received reports indicating that insufficient clearance was found between certain wiring harnesses and the crew oxygen bottle on several in-production and in-service Gulfstream Model GV and GV-SP series airplanes. Interference between the wiring harness and crew oxygen bottle could cause chafing of the electrical wires of the wiring harness and consequent electrical shorting. Electrical shorting, if not prevented, could result in a fire in the underfloor structure of the airplane.
Other Related AD
On August 26, 1998, we issued AD 98-18-15, amendment 39-10731 (63 FR 46870, September 3, 1998), which addresses the same unsafe condition as this AD. AD 98-18-15 is applicable to certain other Gulfstream Model GV series airplanes (serial numbers 501 through 549 inclusive) that are not included in the applicability of this AD. That AD currently requires a one-time inspection to measure the clearance between a certain wiring harness and the crew oxygen bottle; corrective actions, if necessary; and eventual relocation of the crew oxygen bottle and rework of the lines and tubing associated with the crew and passenger oxygen bottles.
Relevant Service Information
We have reviewed the following customer bulletins:
Alert customer bulletin--
Revision level-
Date--
Gulfstream GV Alert Customer Bulletin 21 (for Model GV series airplanes).
Gulfstream G500 Alert Customer Bulletin 1 (for Model GV-SP (G500) series airplanes), including
Gulfstream Drawing 1159SB59987.
Gulfstream G550 Alert Customer Bulletin 1 (for Model GV-SP (G550) series airplanes), including
Gulfstream Drawing 1159SB59987.
Original
Original
A
Original
A
September 13, 2004.
September 13, 2004.
September 8, 2004.
September 13, 2004.
September 8, 2004.
The customer bulletins describe procedures for doing a one-time inspection of the area around the forward end of the crew oxygen bottle, including any supports, for contactor insufficient clearance with any wiring harness, and related investigative and corrective actions if necessary. The related investigative action includes inspecting the wiring for damage if the wiring harness is in contact with the crew oxygen bottle or any supports. The corrective action includes applying Teflon sheeting to the wiring harness if necessary; and contacting the manufacturer if wiring damage is found. Gulfstream GV Alert Customer Bulletin 21 also describes procedures for adjusting the wiring harness to obtain a minimum clearance of 0.250 inch between the crew oxygen bottle and wiring if necessary, and applying Teflon sheeting if necessary. Gulfstream G550 Alert Customer Bulletin 1 and Gulfstream G500 Alert Customer Bulletin 1 also describe procedures for reworking certain wiring bundles. The reworking includes the following actions:
Adding new harness supports to the existing harness supports at stations 241, 253, and 265;
For certain airplanes, relocating thecompletion center wire bundle through the new support, and for certain other airplanes, relocating wire bundle R77 ORG through the new support; and
Inspecting any remaining harness bundles in the area around the passenger and crew oxygen bottles, and redressing any harness bundles that do not meet the minimum separation requirement of 0.500 inch.
Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.
FAA's Determination and Requirements of This AD
The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design. Therefore, we are issuing this AD to prevent chafing of the electrical wires of the wiring harness against the crew oxygen bottle, which could result in electrical shorting and possible fire in the underfloor structure of the airplane. This AD requires accomplishing the actions specified in the service information described previously, except asdiscussed under "Differences Between the AD and Customer Bulletins."
Differences Between the AD and Customer Bulletins
In this AD, the inspections for clearance and damage to wiring specified in the Gulfstream customer bulletins are referred to as "general visual inspections." We have included the definition for a general visual inspection in a note in this AD.
Although the customer bulletins specify that operators may contact the manufacturer for disposition of certain repair conditions, this AD would require operators to repair those conditions according to a method approved by the FAA.
Although the customer bulletins referenced in this AD specify to submit certain information to the manufacturer, this AD does not include that requirement.
FAA's Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD; therefore, providing notice and opportunity for public comment before the AD is issued is impracticable, and good cause exists to make this AD effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include "Docket No. FAA-2004-19492; Directorate Identifier 2004-NM-200-AD" at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search functionof our docket Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.
We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications with you. You can get more information about plain language at http://www/faa.gov/language and http://www.plainlanguage.gov.
Regulatory Findings
We have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.
For the reasons discussed above, I certify that the regulation:
1. Is not a "significant regulatory action" under Executive Order 12866;
2. Is not a "significant rule" under the 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.
We prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. The FAA amends 39.13 by adding the following new airworthiness directive (AD):