E6-19153. Airworthiness Directives; Air Tractor, Inc. Models AT-502, AT-502A, AT-502B, AT-602, AT-802, and AT-802A Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA adopts a new airworthiness directive (AD) for certain Air Tractor, Inc. (Air Tractor) Models AT-502, AT-502A, AT-502B, AT-602, AT-802, and AT-802A airplanes. This AD requires you to repetitively visually inspect the rudder and vertical fin hinge attaching structure (vertical fin skins, spars, hinges, and brackets) for loose fasteners, cracks, and/or corrosion. This AD also requires you to replace any damaged parts found as a result of the inspection and install an external doubler at the upper rudder hinge. This AD results from two reports of in-flight rudder separation from the vertical fin at the upper attach hinge area, and other reports of airplanes with loose hinges, skin cracks, or signs of repairs to the affected area. We are issuing this AD to detect and correct loose fasteners; any cracks in the rudder or vertical fin skins, spars, hinges or brackets; and/or corrosion of the rudder and vertical fin hinge attaching structure. Hinge failure adversely affects ability to control yaw and has led to the rudder folding over in flight. This condition could allow the rudder to contact the elevator and affect ability to control pitch with consequent loss of control.

DATES:

This AD becomes effective on December 21, 2006.

As of December 21, 2006, the Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulation.

ADDRESSES:

To get the service information identified in this AD, contact Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: [phone]; fax: [phone].

To view the AD docket, go to the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590 or on the Internet at http://dms.dot.gov. The docket number is FAA-2006-25260; Directorate Identifier 2006-CE-37-AD.

FOR FURTHER INFORMATION CONTACT:

Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: [phone]; fax: [phone].

SUPPLEMENTARY INFORMATION:

Discussion

On August 3, 2006, we issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Air Tractor Models AT-502, AT-502A, AT-502B, AT-602, AT-802, and AT-802A airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 3, 2006 (71 FR 45451). The NPRM proposed to require you to repetitively visually inspect the rudder and vertical fin hinge attaching structure for loose fasteners, any cracks in the rudder or vertical fin skins, spars, hinges or brackets, or corrosion. The AD would also require you to replace any damaged parts found as a result of the inspection and install an external doubler at the upper rudder hinge. Installation of the external doubler at the upper rudder hinge is terminating action for the repetitive inspection requirements.

Comments

We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA's response to each comment:

Comment Issue No. 1: Availability of Manufacturer Service Information for the Proposed AD

Jack Buster with the Modification and Replacement Parts Association (MARPA) provides comments on the AD process pertaining to how the FAA addresses publishing manufacturer service information as part of a proposed AD action. Mr. Buster states that the proposed rule attempts to require compliance with a public law by reference to a private writing (as referenced in paragraph (e) of the proposed AD). Mr. Buster would like the FAA to incorporate by reference (IBR) Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006; and Snow Engineering Co. Process Specification Number 145, dated December 6, 1991.

We agree with Mr. Buster. However, we do not IBR any document in a proposed AD action, instead we IBR the document in the final rule. Since we are issuing the proposal as a final rule AD action, the previously-referenced Snow Engineering Co. documents are incorporated by reference.

Comment Issue No. 2: Availability of Manufacturer Service Information in the Federal Register or the Docket Management System (DMS)

Mr. Buster also requests IBR documents be made available to the public by publication in the Federal Register or in the DMS.

We are currently reviewing issues surrounding the posting of service bulletins in the Department of Transportation's DMS as part of the AD docket. Once we have thoroughly examined all aspects of this issue and have made a final determination, we will consider whether our current practice needs to be revised.

Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:

• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
• Do not add any additional burden upon the public than was already proposed in the NPRM.

Costs of Compliance

We estimate that this AD affects 945 airplanes in the U.S. registry.

We estimate the following costs to do the inspection:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. Operators
1 work-hour × $80 per hour = $80	Not Applicable	$80	$75,600

Any required “upon-condition” repairs will vary depending upon the damage found, and any replacements required will vary based on the results of the inspection. Based on this, we have no way of determining the potential repair and/or replacement costs for each airplane or the number of airplanes that will need the repairs and/or replacements based on the result of the inspections.

We estimate the following costs to do the installation of the external doubler at the upper rudder hinge:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
5 work-hours × $80 per hour = $400	$217	$617	$583,065

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 AD.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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 this AD:

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 summary of the costs to comply with this AD (and other information as included in the Regulatory Evaluation) and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “Docket No. FAA-2006-25260; Directorate Identifier 2006-CE-37-AD” in your request.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

§ 39.13

[Amended]

2. FAA amends § 39.13 by adding a new AD to read as follows:

2006-23-14 Air Tractor, Inc.: Amendment 39-14826; Docket No. FAA-2006-25260; Directorate Identifier 2006-CE-37-AD.

Effective Date

(a) This AD becomes effective on December 21, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD affects the following airplane models and serial numbers that are certificated in any category:

Model	Serial Nos.
(1) AT-502 and AT-502B	502/502B-0003 through 502/502B-2600.
(2) AT-502A	502A-0003 through 502A-2582.
(3) AT-602	602-0337 through 602-1138.
(4) AT-802 and AT-802A	802/802A-0001 through 802/802A-0215.

Unsafe Condition

(d) This AD results from two reports (one Model AT-602 airplane and one Model AT-802A airplane) of in-flight rudder separations at the upper attach hinge area and other reports of Models AT-502B, AT-602, and AT-802/802A airplanes with loose hinges, skin cracks, or signs of repairs to the affected area. We are issuing this AD to detect and correct loose fasteners; any cracks in the rudder or vertical fin skins, spars, hinges or brackets; and/or corrosion of the rudder and vertical fin hinge attaching structure. Hinge failure adversely affects ability to control yaw and has led to the rudder folding over in flight. This condition could allow the rudder to contact the elevator and affect ability to control pitch with consequent loss of control.

Compliance

(e) To address this problem, you must do the following:

Actions	Compliance	Procedures
(1) Inspect visually the rudder and vertical hinge attachment for loose fasteners; and inspect the rudder or vertical fin skins, spars, hinges or brackets for cracks and/or corrosion	Initially inspect upon reaching 3,500 hours time-in-service (TIS), or within the next 100 hours TIS after December 21, 2006 (the effective date of this AD), whichever occurs later, unless already done. Thereafter, repetitively inspect every 100 hours TIS. Installation of the external doubler at the upper rudder hinge required by paragraph (e)(2)(ii) or (e)(3) of this AD is terminating action for the repetitive inspections required by this AD	Follow Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006.
(2) If you find any damage as a result of any inspection required by paragraph (e)(1) of this AD, you must: (i) Replace any damaged parts with new parts; and (ii) Do the installation of the external doubler at the upper rudder hinge.	Before further flight after any inspection required by paragraph (e)(1) of this AD where you find any damaged parts. The installation of the external doubler at the upper rudder hinge required by paragraph (e)(2)(ii) or (e)(3) of this AD is the terminating action for the repetitive inspections required by this AD	Follow Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006, and Snow Engineering Co. Process Specification Number 145, dated December 6, 1991.
(3) Do the installation of the external doubler at the upper rudder hinge	Upon accumulating 5,000 hours TIS or within the next 100 hours TIS after the effective date of this AD, whichever occurs later, unless already done. The installation of the external doubler at the upper rudder hinge required by paragraph (e)(2)(ii) or (e)(3) of this AD is the terminating action for the repetitive inspections required by this AD	Follow Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006, and Snow Engineering Co. Process Specification Number 145, dated December 6, 1991.
(4) Do not install any rudder without the external doubler at the upper rudder hinge required by paragraph (e)(3) of this AD	As of December 21, 2006 (the effective date of this AD)	Not Applicable.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Fort Worth Aircraft Certification Office, FAA, ATTN: Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: [phone]; fax: [phone], has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

(g) You must use Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006; and Snow Engineering Co. Process Specification Number 145, dated December 6, 1991, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: [phone]; fax: [phone].

(3) You may review copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 64106; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​ code_of_federal_ regulations/ibr_locations.html.

Issued in Kansas City, Missouri, on November 3, 2006.

James E. Jackson,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.