Airworthiness Directives; Viking Air Limited Model DHC-7 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 all Viking Air Limited Model DHC-7 airplanes. This proposed AD would require an inspection of certain SM-200 servo drive units (power servo motor and housing assemblies) for certain markings, related investigative action if necessary, and modification if necessary. This proposed AD results from a report that some SM-200 servo drive units that were not in configuration MOD H are installed on Model DHC-7 airplanes. MOD H prevents the internal clutch fasteners from backing out. We are proposing this AD to prevent the possibility of internal clutch fasteners from backing out, which could cause an inadvertent servo engagement and consequent reduced controllability of the airplane.

DATES:

We must receive comments on this proposed AD by August 6, 2007.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• 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.
• Fax: (202) 493-2251.
• Hand Delivery: Room W12-140 on the ground floor of the West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Viking Air Limited, 9574 Hampden Road, Sidney, British Columbia V8L 5V5, Canada, for service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Ezra Sasson, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 228-7320; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2007-28619; Directorate Identifier 2007-NM-004-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov,, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone (800) 647-5527) is located on the ground floor of the West Building at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified us that an unsafe condition might exist on all Viking Air Limited Model DHC-7 airplanes. TCCA advises that investigation revealed that some SM-200 servo drive units (power servo motor and housing assemblies) within certain date codes installed on the automatic flight control system of the de Havilland DHC-7 aircraft were mislabeled as having been manufactured to MOD H configuration when, in fact, they did not have MOD H installed. MOD H prevents the possibility of internal clutch fasteners from backing out. This condition, if not corrected, could result in the internal clutch fasteners backing out, which could cause an inadvertent servo engagement and consequent reduced controllability of the airplane.

Relevant Service Information

Viking has issued Alert Service Bulletin 7-22-20, dated May 29, 2006. The alert service bulletin describes procedures for doing an inspection of the SM-200 power servo motor and housing assembly, part numbers 4006719-904, -913, and -933, to determine if MOD H is marked, related investigative action if necessary, and modification of the power servo motor and housing assembly if necessary. The related investigative action is an inspection for certain dates of power servo motor and housing assemblies that have been marked MOD H. Modifications are done if MOD H is not marked on the power servo motor and housing assembly and if power servo motor and housing assemblies that have been marked MOD H are within certain dates. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. TCCA mandated the service information and issued Canadian airworthiness directive CF-2006-18, dated July 17, 2006, to ensure the continued airworthiness of these airplanes in Canada.

The alert service bulletin refers to Honeywell Alert Service Bulletin 4006719-22-A0016 (Pub. No. A21-1146-008), Revision 001, dated November 1, 2004 as an additional source of service information for doing the inspection and modification.

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 accomplishing the actions specified in the service information described previously.

Costs of Compliance

The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

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
• 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.