Airworthiness Directives; Bombardier Model DHC-8-102 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 Bombardier Model DHC-8-102 airplanes. This proposal would require modification of the electrical power circuit. This action is necessary to prevent component failure in the radar indicator, resulting in an overcurrent condition and consequent overheating or burning of an internal component or the ribbon cable. This could lead to smoke in the cockpit, resulting in incapacitation of the flight crew and loss of control of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 7, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-185-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. 2003-NM-185-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 the proposed rule may be obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 123 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 New York Aircraft Certification Office (ACO), 1600 Stewart Ave., Westbury, New York.

FOR FURTHER INFORMATION CONTACT:

Doug Wagner, Electrical Systems Engineer, ANE-172, FAA, New York Aircraft Certification Office, 1600 Stewart Ave., Westbury, New York 11590; telephone (516) 228-7306; fax (516) 794-5531.

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-185-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-185-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified the FAA that an unsafe condition exists on certain Bombardier Model DHC-8-102 airplanes. TCCA advises that it has received reports of smoke in the cockpit. The cause has been attributed to insufficient circuit protection being provided by the existing circuit breaker in the avionics circuit breaker panel leading to component failure in the radar indicator, resulting in an overcurrent condition and consequent overheating or burning of an internal component or the ribbon cable. This condition, if not corrected, could lead to smoke in the cockpit, resulting in incapacitation of the flight crew and loss of control of the airplane.

Explanation of Relevant Service Information

Bombardier has issued Modification Summary Package (ModSum) IS8Q3450000, Revision A, released October 16, 2002, which describes procedures for modification of the electrical power circuit. The modification includes replacing the 7.5 ampere (amp) circuit breaker on the avionics circuit breaker panel with a new 5.0 amp circuit breaker; installing an additional 3.0 amp circuit breaker for the radar indicator; re-terminating existing connecting wires; taping and stowing existing wires; adding new wires (routing new wires with existing wires); and performing an operational test of the weather radar system; as applicable. Accomplishment of the actions specified in the ModSum is intended to adequately address the identified unsafe condition. TCCA classified this ModSum as mandatory and issued Canadian airworthiness directive CF-2003-13, effective June 20, 2003, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

This airplane model is manufactured in Canada and is type certificated for operation in the United States under the provisions of § 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 the FAA informed of the situation described above. The FAA has 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 Rule

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 require accomplishment of the actions specified in the ModSum described previously.

Cost Impact

The FAA estimates that 48 Model DHC-8-102 airplanes of U.S. registry would be affected by this proposed AD. The average labor rate is $65 per work hour and the estimated time to accomplish this proposed AD is between 3 work hours and 9 work hours per airplane. Required parts would cost $150 per airplane. Total estimated cost would be between $16,560 and $35,280, or between $345 and $735 per airplane.

The cost impact figures discussed above are 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 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.