04-6679. Airworthiness Directives; Raytheon Model BAe.125 Series 800A, 800A (C-29A), and 800B Airplanes; and Model Hawker 800 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Model BAe.125 series 800A, 800A (C-29A), and 800B airplanes; and Model Hawker 800 airplanes. This proposal would require a one-time inspection of certain wire bundles for discrepancies and related corrective action. This action is necessary to find and fix chafing and damage to the wire bundles, which could result in electrical arcing and heat damage in a potential fuel zone and possible fire or explosion in the fuel tank. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 10, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-244-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-244-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 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Raytheon Aircraft Company, Department 62, P.O. Box 85, Wichita, Kansas 67201-0085. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas.

FOR FURTHER INFORMATION CONTACT:

Philip Petty, Aerospace Engineer, Systems and Propulsion Branch, ACE-116W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

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 proposed 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 proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-244-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-244-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports indicating that wires from the fuel boost pump of relays “KT” and “JT” interfered with and chafed against the avionics wire bundle that was routed through pressure bung “DD” and the wing fuel transfer valve lever. This occurred because sufficient clearance was not attained during the manufacturing process. One incident resulted in a short circuit of the affected fuel boost pump wires against the radio altimeter coax cables. Chafing and damage to the wire bundles could result in electrical arcing and heat damage in a potential fuel zone, and possible fire or explosion in the fuel tank.

Explanation of Relevant Service Information

We have reviewed and approved Raytheon Service Bulletin SB 24-3588, Revision 1, dated September 2003, which describes procedures for a one-time inspection for discrepancies (chafing, damage, adequate clearance); of the wire bundles extending from relays “JT” and “KT” on Panel “JA”; the wire bundle entering pressure bung “DD”; and the wire bundles adjacent to relay “KT” and against the wing fuel transfer valve lever, and related corrective action. The inspection includes securing the wire bundles with cable ties if clearance is adequate (minimum clearance between wire bundles is 0.25 inch), to maintain adequate clearance. The related corrective action includes the following:

• Repairing or replacing any damaged wires, as applicable.
• Replacing or splicing wires to achieve adequate clearance if clearance is inadequate.
• If clearance is inadequate between the wire bundles, and the wire bundles and relay boxes: Installing P-clips to maintain clearance after adequate clearance is attained.
• If clearance is inadequate between the wiring extending from relay “KT” and the wing fuel transfer valve lever: Installing P-clips to maintain clearance after adequate clearance is attained.

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Between This Proposed AD and Service Bulletin

The service bulletin recommends accomplishing the inspection for discrepancies of the wire bundles within 10 flight hours or 30 days, whichever is first, however; this proposed AD allows accomplishment of the inspection within 125 flight hours or 90 days, whichever is first. In developing an appropriate compliance time for this proposed AD, we 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 (1 hour). In light of all of these factors, we find a compliance time of within 125 flight hours or 90 days, whichever is first, represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

The service bulletin refers to an “inspection” of certain wire bundles for discrepancies, but we have determined that the procedures in the service bulletin should be described as a “detailed inspection.” Note 1 has been included in this proposed AD to define this type of inspection.

Cost Impact

There are about 184 airplanes of the affected design in the worldwide fleet. We estimate that 110 airplanes of U.S. registry would be affected by this proposed AD, that it would take about 1 work hour per airplane to accomplish the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the inspection proposed by this AD on U.S. operators is estimated to be $7,150, or $65 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed 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 proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed 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) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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:

Raytheon Aircraft Company: Docket 2003-NM-244-AD.

Applicability: Model BAe.125 series 800A, 800A (C-29A), and 800B airplanes; and Model Hawker 800 airplanes, as listed in Raytheon Service Bulletin SB 24-3588, Revision 1, dated September 2003; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To find and fix chafing and damage to certain wire bundles, which could result in electrical arcing and heat damage in a potential fuel zone and possible fire or explosion in the fuel tank, accomplish the following:

One-Time Inspection/Corrective Action

(a) Within 125 flight hours or 90 days after the effective date of this AD, whichever is first: Do a one-time detailed inspection for discrepancies of the wire bundles extending from relays ‘JT’ and ‘KT’ on Panel ‘JA,’ and the wire bundle entering pressure bung ‘DD'; and do any related corrective action; by doing all the actions per Part 3.A. of the Accomplishment Instructions of Raytheon Service Bulletin SB 24-3588, Revision 1, dated September 2003. Do any related corrective action before further flight.

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.”

Inspections/Corrective Action Accomplished Per Previous Issue of Service Bulletin

(b) Inspections and corrective action accomplished before the effective date of this AD per Raytheon Service Bulletin SB 24-3588, dated February 2003, are considered acceptable for compliance with the corresponding actions specified in this AD.

Alternative Methods of Compliance

(c) In accordance with 14 CFR 39.19, the Manager, Wichita Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance (AMOCs) for this AD.

Issued in Renton, Washington, on March 19, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.