AD 98-07-26

The FAA has received a report indicating that, soon after takeoff on a Boeing Model 767 series airplane, the engine indication and crew alerting system (EICAS) displayed several caution messages and several circuit breakers tripped. After landing, the cabin crew reported smoke coming from the forward galley air chiller, located below the forward galley door under the floor.

The smoke was produced by burning electrical wires. Investigation revealed that approximately 30 wires were damaged in bundles W272, W656, W782, and W254, forward of the P37 panel, adjacent to the AE0218 disconnect panel, and above the aft side of the forward galley air chiller. Further investigation revealed that the wire bundles do not have protective taping or sleeves and that adequate clearance does not exist between the wire bundles and the adjacent chiller. As a result, during the removal or reinstallation of the forward galley air chiller, the wire bundles may become damaged or chafed. When the insulation of the wire bundles is damaged or chafed, additional elements such as moisture, vibration, or conductive debris can result in arcing of the conductors.

These conditions, if not corrected, could result in burning of the damaged wires and the adjacent electrical wire bundles and consequent fire hazard for passengers and crewmembers, and failure of essential electrical systems.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Message Number M-7200-98-00140, dated January 11, 1998, which describes procedures for a detailed visual inspection(s) for damage or chafing of the electrical wire bundles located in the right-hand outboard electronics equipment bay and for adequate clearance between the wire bundles and adjacent forward galley air chiller; and follow-on corrective actions. Boeing Message Number M-7200-98-00140, dated January 11, 1998, also references Boeing Standard Wiring Practices Manual (SWPM) D6-54446, as an additional source of service information.

Explanation of the Requirement of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent arcing between exposed conductors, which could result in burning of the damaged wires and adjacent electrical bundles and consequent fire hazard for passengers and crewmembers, and failure of essential electrical systems. This AD requires accomplishment of the actions specified in the Boeing message described previously, except as discussed below.

Differences Between Rule and Service Bulletin

While the Boeing Message Number M-7200-98-00140 does not describe procedures for repetitive inspections, this AD requires repetitive inspections for certain inspection results. For these certain inspection results, the FAA is not proposing to mandate the installation of protective tape or a sleeve over the wire bundles for several reasons:

1. Accessing the wire bundles located forward of the P37 panel is easily accomplished.

2. The subject damage or chafing is easily detectable by means of a detailed visual inspection.

3. The failure of the wire bundles may adversely affect essential electrical systems; however, the detailed visual inspection will detect any damage or chafing of the wire bundles before they result in a hazardous condition.

Determination of 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's ideas 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 concernedwith 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 98-NM-95-AD." The postcard will be date stamped and returned to the commenter.

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.

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 itis 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 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: