Airworthiness Directives; Bombardier Model DHC-8-100 and DHC-8-200 Series Airplanes, and Model DHC-8-301, -311, and -315 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT)

ACTION:

Notice of Proposed Rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model DHC-8-100 and DHC-8-200 series airplanes, and DHC-8-301, -311, and -315 airplanes. This proposed AD would require implementing a corrosion prevention and control program (CPCP) either by accomplishing specific tasks or by revising the maintenance inspection program to include a CPCP. This proposed AD results from the determination that, as airplanes age, they are more likely to exhibit indications of corrosion. We are proposing this AD to prevent structural failure of the airplane due to corrosion.

DATES:

We must receive comments on this proposed AD by September 14, 2009.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov . Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Bombardier, Inc., 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-7401; e-mail thd.qseries@aero.bombardier.com; Internet http://www.bombardier.com . You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov ; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Pong K. Lee, Aerospace Engineer, Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 228-7324; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2009-0712; Directorate Identifier 2007-NM-152-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified us that an unsafe condition may exist on certain Bombardier Model DHC-8-100 and DHC-8-200 series airplanes, and Model DHC-8-301, -311, and -315 airplanes. TCCA advises that, as airplanes age, they are more likely to exhibit indications of corrosion. Operators must implement a Corrosion Prevention and Control Program (CPCP) that identifies specific areas to be inspected to minimize and control deterioration of the airplane from corrosion. This condition, if not corrected, could result in structural failure of the airplane.

Relevant Service Information

Bombardier has issued Part 1, Section 3, Structural Inspection Program, of the following de Havilland Dash 8 Maintenance Program MRB (Maintenance Review Board) Reports. In this proposed AD, we refer to these publications as the “manual.”

• Program Support Manual (PSM) 1-8-7, Revision 22, dated November 1, 2008, for Bombardier Model DHC-8-100 series airplanes.
• PSM 1-82-7, Revision 13, dated November 1, 2008, for Bombardier Model DHC-8-200 series airplanes.
• PSM 1-83-7, Revision 22, dated November 1, 2008, for Bombardier Model DHC-8-300 series airplanes.

The manual provides a basic structural inspection schedule, which is intended to ensure continuous airworthiness. Only primary structures defined as Structurally Significant Items (SSIs) and secondary structures whose failure may adversely affect the systems' functions are included in the manual. Canadian airworthiness requirements state that the aircraft maintenance program must identify specific inspections under the CPCP. For the affected airplanes, the CPCP includes a complete re-analysis of the structural inspection program, supported by in-service engineering findings. New and revised tasks identified as CPCP are annotated in the manual as ED/CPCP. ED stands for “environmental damage.”

TCCA mandated the service information and issued Canadian Airworthiness Directive CF-2007-06, dated April 10, 2007, to ensure the continued airworthiness of these airplanes in Canada.

Levels of Corrosion

The Canadian Airworthiness Directive refers to levels of corrosion. For the purposes of this proposed AD, the levels are defined in Part 1 of the Bombardier (de Havilland) DHC-6 Twin Otter, Dash 7 & Dash 8 Corrosion Prevention and Control Manual PSM 1-GEN-5, Revision 3, dated November 30, 1998, as follows:

• Level 1 corrosion:

1. Occurs between repetitive inspections, is local, and can be reworked within certain limits; or

2. Is local but exceeds allowable limits and is attributed to an event not typical of the usage of the other airplanes in the operator's fleet; or

3. Exceeds allowable limits but for which only light corrosion has been found in previous inspections.

• Level 2 corrosion:

1. Occurs between repetitive inspections and exceeds allowable limits, necessitating a repair or complete replacement of a structural significant element; or

2. Occurs between repetitive inspections, is widespread, and requires a rework approaching allowable limits.

• Level 3 corrosion is found during initial or repetitive inspections and is determined to be a potentially urgent unsafe condition necessitating expeditious action.

FAA's Determination and Requirements of the Proposed AD

These airplanes 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 the FAA informed of the situation described above. We have examined TCCA's findings, evaluated all pertinent information, and determined that we need to issue an AD for airplanes of this type design that are certificated for operation in the United States.

Therefore, we are proposing this AD, which would require implementing a CPCP either by accomplishing specific tasks or by revising the maintenance inspection program to include a CPCP. The proposed AD would require you to use the manual described previously to perform these actions. The proposed AD also would require you to report findings of Level 3 corrosion to the airplane manufacturer and to the FAA.

Costs of Compliance

This proposed AD would affect about 154 airplanes of U.S. registry. There are between 16 and 17 specific inspections, depending on the applicable manual identified in Table 1 of this AD. The proposed inspections would take about 53 work hours per airplane, per inspection cycle, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $652,960, or $4,240 per airplane, per inspection cycle.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.