Airworthiness Directives; GARMIN International GSM 85 Servo Gearbox Units

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain GARMIN International (GARMIN) GSM 85 servo gearbox units that are installed on airplanes. This proposed AD would require you to inspect the GSM 85 servo gearbox for foreign object debris and return the unit to the manufacturer for replacement if you find debris. This proposed AD results from reports of certain GARMIN GSM 85 servo gearbox units that have foreign object debris inside the assembly. We are proposing this AD to detect and correct defective GARMIN GSM 85 servo gearbox units, which could result in jamming of the gearbox. Jamming of the gearbox could lead to the pilot having to apply excessive manual force to control the airplane.

DATES:

We must receive comments on this proposed AD by October 22, 2007.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD:

• DOT Docket Web site: Go to http://dms.dot.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: 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.
• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

For service information identified in this proposed AD, contact GARMIN International Inc., 1200 East 151st Street, Olathe, KS 66062; telephone: 913-397-8200; fax: 913-397-8282.

FOR FURTHER INFORMATION CONTACT:

Roger A. Souter, Aerospace Engineer, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: 316-946-4134; fax: 316-946-4107; e-mail address: roger.souter@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number, “FAA-2007-28730; Directorate Identifier 2007-CE-063-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 we receive concerning this proposed AD.

Discussion

We have received reports of certain GARMIN GSM 85 servo gearbox units having foreign object debris inside the assembly. The debris was found during installation and removal.

The GSM 85 servo gearbox extrusion (housing) is composed primarily of aluminum. The manufacturer selectively uses a tumbling process to deburr the housing, which resulted in foreign object debris collecting in the housing cavities.

We have determined that foreign object debris inside the gear-assembly housing may come loose causing the GSM 85 servo gearbox to jam.

This condition, if not corrected, could result in the GSM 85 servo gearbox unit becoming jammed. Jamming of the servo gearbox could lead to the pilot having to apply excessive manual force to control the airplane.

Relevant Service Information

We have reviewed GARMIN International, Inc. Service Bulletin No. 0713, Revision A, dated May 7, 2007; GARMIN International, Inc. Service Bulletin No. 0713, Revision B, dated May 18, 2007; GARMIN International, Inc. Service Bulletin No. 0713, Revision C, dated May 29, 2007; and GARMIN International, Inc. Service Bulletin No. 0713, Revision D, dated June 13, 2007. These service bulletins describe procedures for inspecting the GSM 85 servo gearbox for foreign object debris and returning the unit to the manufacturer for replacement if debris is found.

FAA's Determination and Requirements of the Proposed AD

We are proposing this AD because we evaluated all information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design. This proposed AD would require you to inspect the GSM 85 servo gearbox for foreign object debris and return the unit to the manufacturer for replacement if you find debris.

Costs of Compliance

We estimate that this proposed AD would affect 900 airplanes in the U.S. registry.

We estimate the following costs to do the proposed inspection:

For airplanes that would need to replace the GSM 85 servo gearbox based on the results of the proposed inspection, we estimate the following costs to set the torque value of the slip-clutch breakaway required for installation. We have no way of determining the number of airplanes that may need this replacement:

Warranty credit will be given to the extent specified in the service information.

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.

Examining the AD Docket

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

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.