Airworthiness Directives; Boeing Model 747-400 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-400 series airplanes. This action requires a one-time inspection to determine if certain wire bundles are routed incorrectly and to detect damage, and corrective actions, if necessary. This action is necessary to prevent damage of certain wire bundles routed to the fuel tank transfer pumps in the horizontal stabilizer, which could result in electrical arcing and a possible fire adjacent to the fuel tank. This action is intended to address the identified unsafe condition.

DATES:

Effective August 9, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of August 9, 2000.

Comments for inclusion in the Rules Docket must be received on or before September 25, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-151-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-iarcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-151-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT:

Sulmo Mariano, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2686; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

The FAA has received a report indicating that, during a flight test in production, the flight crew reported the advisory message “FUEL PMP STAB R” and the caution message “FUEL STAB XFR” were displayed on the engine indicating and crew alerting system. Inspection revealed that a certain wire bundle routed to the fuel tank transfer pumps in the horizontal stabilizer was “pinched” between the head of a clamp fastener and adjacent structure. Evidence of arcing was also detected. Investigation revealed that the wire bundle was routed incorrectly through a clamp near the transfer pump. This condition, if not corrected, could result in electrical arcing and a possible fire adjacent to the fuel tank.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 747-28A2232, Revision 1, dated June 22, 2000, which describes procedures for a one-time visual inspection of wire bundles routed to the fuel tank transfer pumps in the horizontal stabilizer to determine if wire bundles W4601 and W4602 are routed correctly and to detect damage, and corrective action, if necessary. Corrective action includes rerouting any wire bundle that is routed incorrectly and repairing any damaged wiring. Accomplishment of the actions specified in the alert service bulletin is intended to adequately address the identified unsafe condition.

Explanation of the Requirements 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 damage of certain wire bundles routed to the fuel tank transfer pumps in the horizontal stabilizer, which could result in electrical arcing and a possible fire adjacent to the fuel tank. This AD requires accomplishment of the actions specified in the alert service bulletin described previously, except as discussed below.

Differences Between This AD and Alert Service Bulletin

Operators should note that this AD requires accomplishment of the inspection within 60 days after the effective date of this AD. The alert service bulletin recommends that operators accomplish the actions in the bulletin “at their earliest opportunity when manpower and facilities are available.” In developing an appropriate compliance time for this AD, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the inspection (less than one hour). In light of all of these factors, the FAA finds a 60-day compliance time for initiating the required actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

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.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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-151-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 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.

2. Section 39.13 is amended by adding the following new airworthiness directive:

2000-15-02 Boeing: Amendment 39-11831. Docket 2000-NM-151-AD.

Applicability: Model 747-400 series airplanes having line numbers (L/N) 1162 through 1223, except L/N 1174; equipped with horizontal stabilizer fuel tanks; 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 damage of certain wire bundles routed to the fuel tank transfer pumps in the horizontal stabilizer, which could result in electrical arcing and a possible fire adjacent to the fuel tank, accomplish the following:

One-Time Inspection and Corrective Actions

(a) Within 60 days after the effective date of this AD, perform a one-time detailed visual inspection of wire bundles routed to the fuel tank transfer pumps in the horizontal stabilizer to determine if wire bundles W4601 and W4602 are routed correctly and to detect damage, in accordance with Boeing Alert Service Bulletin 747-28A2232, Revision 1, dated June 22, 2000.

(1) If the wire bundles are routed correctly and no damage is detected, no further action is required by this AD.

(2) If either wire bundle is determined to be incorrectly routed, but no damage is detected, prior to further flight, reroute the affected wire bundle in accordance with the alert service bulletin.

(3) If any damage is detected (whether the wire bundles are routed properly or not), prior to further flight, repair the affected wire bundle and route the wire bundle correctly, as applicable, in accordance with the alert service bulletin.

Note 2:

For the purposes of this AD, a detailed visual 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.”

Note 3:

Inspections and corrective actions accomplished prior to the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-28A2232, dated March 2, 2000, are considered acceptable for compliance with the applicable action specified in this amendment.

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, Seattle Aircraft Certification Office (ACO), 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, Seattle ACO.

Note 4:

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

Special Flight Permits

(c) Special flight permits may be issued in accordance with §§ 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 Boeing Alert Service Bulletin 747-28A2232, Revision 1, dated June 22, 2000. 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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. 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.

Effective Date

(e) This amendment becomes effective on August 9, 2000.