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Proposed Rule

Airworthiness Directives; Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 Airplanes

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Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 airplanes, that currently requires a one-time inspection to detect chafing of electrical wires in the cable trough below the cabin floor; repair, if necessary; installation of additional tie-mounts and tie-wraps; and application of sealant to rivet heads. This action would add an additional modification of the electrical wires in certain sections. The actions specified by the proposed AD are intended to prevent chafing of electrical wires, which could result in an uncommanded shutdown of an engine during flight. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by November 19, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-11-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-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-11-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 Bombardier, Inc., Bombardier Regional Aircraft Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York.

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FOR FURTHER INFORMATION CONTACT:

Douglas G. Wagner, Aerospace Engineer, Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone (516) 256-7506; fax (516) 568-2716.

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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 2002-NM-11-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. 2002-NM-11-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On September 28, 1999, the FAA issued AD 99-21-09, amendment 39-11352 (64 FR 54199, October 6, 1999), which superseded AD 98-20-14, amendment 39-10781 (63 FR 50501, September 22, 1998), applicable to certain Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 series airplanes. That AD requires a one-time inspection to detect chafing of electrical wires in the cable trough below the cabin floor; repair, if necessary; installation of additional tie-mounts and tie-wraps; and application of sealant to rivet heads. That action was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The requirements of that AD are intended to prevent chafing of electrical wires, which could result in an uncommanded shutdown of an engine during flight.

Actions Since Issuance of Previous Rule

Since the issuance of AD 99-21-09, Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, has informed us that an uncommanded engine shutdown during flight occurred on a Bombardier Model DHC-8 airplane. The shutdown was due to a short circuit between adjacent wires located in the cable trough below the cabin floor, which sent a 28-volt signal to the fuel shutoff valve. Investigation revealed that the short Start Printed Page 59893circuit was caused by chafing of the wires on the sharp edges of the cherrymax rivets in the cable trough. Such chafing of electrical wires could result in an uncommanded shutdown of an engine during flight.

Explanation of Relevant Service Information

Bombardier has issued Service Bulletin 8-53-80, Revision “A”, dated July 25, 2000, which describes procedures for an additional modification of the electrical wires in the cable trough below the cabin floor. The modification is to be done in sections X510.00 to X580.50 of the cable trough; those sections were inadvertently omitted from the modification specified in Bombardier Service Bulletin 8-53-66, dated March 27, 1998 (the service bulletin referenced in the existing AD). TCCA classified Service Bulletin 8-53-80, Revision “A”, as mandatory and issued Canadian airworthiness directive CF-1998-08R2, dated July 10, 2000, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

These airplane models are manufactured in Canada and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, TCCA has kept us informed of the situation described above. We have examined the findings of TCCA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed AD

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would supersede AD 99-21-09 to continue to require a one-time inspection to detect chafing of electrical wires in the cable trough below the cabin floor; repair, if necessary; installation of additional tie-mounts and tie-wraps; and application of sealant to rivet heads. The proposed AD would add an additional modification of the electrical wires in certain sections. The actions would be required to be accomplished in accordance with the service bulletin described previously, except as discussed below.

Difference Between This Proposed AD and Service Bulletin

Although the service bulletin specifies to submit certain information to the manufacturer, the proposed AD does not include such a requirement.

Cost Impact

There are approximately 173 airplanes of U.S. registry that would be affected by this proposed AD.

The actions that are currently required by AD 99-21-09 take between 80 and 100 work hours per airplane (depending on the airplane model) to accomplish, at an average labor rate of $65 per work hour. Required parts are provided by the manufacturer at no cost to the operator. Based on these figures, the cost impact of the currently required actions is estimated to be between $5,200 and $6,500 per airplane.

The additional modification that is proposed in this AD action would take approximately 10 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts would be provided by the manufacturer at no cost to the operator. Based on these figures, the cost impact of the proposed modification on U.S. operators is estimated to be $112,450, or $650 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this 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.

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List of Subjects in 14 CFR Part 39

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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:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. Section 39.13 is amended by removing amendment 39-11352 (64 FR 54199, October 6, 1999), and by adding a new airworthiness directive (AD), to read as follows:

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 2002-NM-11-AD. Supersedes AD 99-21-09, Amendment 39-11352.

Applicability: Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 series airplanes; serial numbers 3 through 540 inclusive, excluding serial number 462; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent chafing of electrical wires, which could result in an uncommanded shutdown of an engine during flight, accomplish the following:

Restatement of Requirements of AD 99-21-09

One-Time Inspection, Corrective Action, and Modification

(a) Perform a one-time general visual inspection to detect chafing of electrical wires in the cable trough below the cabin floor; install additional tie-mounts and tie-wraps; and apply sealant to rivet heads (reference Bombardier Modification 8/2705); in accordance with Bombardier Service Bulletin 8-53-66, dated March 27, 1998, at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable. If any chafing is detected during the inspection required by this paragraph, prior to further flight, repair in accordance with the service bulletin.

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Note 1:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(1) For airplanes having serial numbers 3 through 519 inclusive, excluding serial number 462: Inspect within 36 months after October 27, 1998 (the effective date of AD 98-20-14, amendment 39-10781).

(2) For airplanes having serial numbers 520 through 540 inclusive: Inspect within 36 months after November 10, 1999 (the effective date of AD 99-21-09, amendment 39-11352, which superseded AD 98-20-14), or at the next “C” check, whichever occurs first.

New Requirements of This AD

Modification

(b) For all airplanes: Within 36 months after the effective date of this AD; modify the electrical wires in the cable trough below the cabin floor at Sections X510.00 to X580.50 (including a general visual inspection and any applicable repair) per Part III, paragraphs 1 through 9 and 12 through 20, of the Accomplishment Instructions of Bombardier Service Bulletin 8-53-80, Revision “A”, dated July 25, 2000. Any applicable repair must be done before further flight.

Alternative Methods of Compliance

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

Note 2:

The subject of this AD is addressed in Canadian airworthiness directive CF-1998-08R2, dated July 10, 2000.

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Issued in Renton, Washington, on October 14, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 03-26368 Filed 10-17-03; 8:45 am]

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