Airworthiness Directives: Air Tractor, Inc. Models AT-402, AT-402A, and AT-402B Airplanes

Federal Register: July 8, 2008 (Volume 73, Number 131)

Proposed Rules

Page 38933-38935

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr08jy08-23

Proposed Rules

Federal Register

This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules.

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 14 CFR Part 39

Docket No. FAA-2008-0749; Directorate Identifier 2008-CE-044-AD

RIN 2120-AA64

Airworthiness Directives; Air Tractor, Inc., Models AT-402, AT- 402A, and AT-402B Airplanes

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 Air Tractor, Inc., (Air Tractor) Models AT-402, AT-402A, and

AT-402B airplanes. This proposed AD would require you to repetitively visually inspect the rudder and vertical fin hinge attaching structure for loose fasteners and inspect the rudder or vertical fin skins, spars, hinges or brackets for cracks and/or corrosion. The AD would also require you to replace any damaged parts found as a result of the inspections 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. This proposed AD results from a report of a Model AT-402 airplane with a loose upper rudder hinge caused by fatigue. We are proposing this AD to detect and correct loose fasteners; any cracks in the rudder or vertical fin skins, spars, hinges or brackets; 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: We must receive comments on this proposed AD by September 8, 2008.

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

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 Air

Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564- 5616; facsimile: (940) 564-5612.

FOR FURTHER INFORMATION CONTACT: Andrew McAnaul, Aerospace Engineer,

ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio,

Texas 78216; telephone: (210) 308-3365; facsimile: (210) 308-3370.

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- 2008-0749; Directorate Identifier 2008-CE-044-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:// www.regulations.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 received two reports (one Air Tractor Model AT-602 airplane and one Model AT-802A airplane) of in-flight rudder separation 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.

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.

Consequently, we issued AD 2006-23-14 (71 FR 66661, November 16, 2006). AD 2006-23-14 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.

Since issuing AD 2006-23-14, we have received a report of a Model

AT-402 airplane with a loose upper rudder hinge caused by fatigue.

Therefore, we are proposing this AD to address the unsafe condition on the Model AT-402 airplanes.

Relevant Service Information

We have reviewed Snow Engineering Co. Service Letter 247, revised June 2, 2008; and Snow Engineering Co. Process Specification

Number 145, dated December 6, 1991. The service information describes procedures for:

Inspecting (visually) the rudder and fin hinge attaching structure for loose fasteners, any cracks in the rudder or vertical fin skins, spars, hinges or brackets, or corrosion;

Replacing any damaged parts found as a result of the inspection;

Installing an external doubler at the upper rudder hinge; and

Balancing of the rudder.

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 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. This proposed AD would also require you to replace any damaged parts found as a result of the inspection

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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.

Costs of Compliance

We estimate that this proposed AD would affect 220 airplanes in the

U.S. registry.

We estimate the following costs to do the proposed inspection:

Total cost per Total cost on

Labor cost

Parts cost

airplane

U.S. operators

1 work-hour x $80 per hour = $80............. Not applicable.................

$80

$17,600

Any required 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 proposed installation of the external doubler at the upper rudder hinge:

Total cost per

Labor cost

Parts cost

airplane

5 work-hours x $80 per hour = $400....

$217

$617

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://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 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.

Sec. 39.13 [Amended] 2. The FAA amends Sec. 39.13 by adding the following new AD:

Air Tractor, Inc.: Docket No. FAA-2008-0749; Directorate Identifier 2008-CE-044-AD.

Comments Due Date

(a) We must receive comments on this airworthiness directive

(AD) action by September 8, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Models AT-402, AT-402A, and AT-402B airplanes, serial numbers 0694 through 1176, that are certificated in any category.

Unsafe Condition

(d) This AD results from a report of a Model AT-402 airplane with a loose upper rudder hinge caused by fatigue. We are issuing this AD to detect and correct loose fasteners; any cracks in the rudder or vertical fin skins, spars, hinges or brackets; 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, unless already done:

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Actions

Compliance

Procedures

(1) Inspect visually the rudder Initially inspect Follow Snow and vertical fin hinge

when the airplane Engineering Co. attachment for loose fasteners; reaches a total

Service Letter and inspect the rudder or

of 3,500 hours

247, vertical fin skins, spars,

time-in-service

revised June 2, hinges or brackets for cracks

(TIS) or within

2008. and/or corrosion.

the next 100 hours TIS after the effective date of this AD, whichever occurs later, unless already done.

Thereafter, repetitively inspect at intervals not to exceed 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.

(2) If you find any damage as a Before further

Follow Snow result of any inspection

flight after any

Engineering Co. required by paragraph (e)(1) of inspection

Service Letter this AD, you must:

required by

247,

(i) Replace any damaged parts

paragraph (e)(1) revised June 2, with new parts and.

of this AD where 2008; and Snow

(ii) Do the installation of the you find any

Engineering Co. external doubler at the upper

damaged parts.

Process rudder hinge..

The installation

Specification of the external

Number 145, dated doubler at the

December 6, 1991. upper rudder hinge required by paragraph

(e)(2)(ii) or

(e)(3) of this AD terminates the action for the repetitive inspections required by this

AD.

(3) Do the installation of the

When the airplane Follow Snow external doubler at the upper

reaches a total

Engineering Co. rudder hinge.

of 5,000 hours

Service Letter

TIS after the

247, effective date of revised June 2, this AD or within 2008; and Snow the next 100

Engineering Co. hours TIS after

Process the effective

Specification date of this AD,

Number 145, dated whichever occurs

December 6, 1991. 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 terminates the action for the repetitive inspections required by this

AD.

(4) Do not install any rudder

As of the

Not Applicable. without the external doubler at effective date of the upper rudder hinge required this AD. by paragraph (e)(3) of this AD.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Fort Worth Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN:

Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100

Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: (210) 308-3365; facsimile: (210) 308-3370. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office

(FSDO), or lacking a PI, your local FSDO.

Related Information

(g) To get copies of the service information referenced in this

AD, contact Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564-5616; facsimile: (940) 564-5612. To view the AD docket, go to U.S. Department of Transportation, Docket Operations,

M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey

Avenue, SE., Washington, DC 20590, or on the Internet at http:// www.regulations.gov.

Issued in Kansas City, Missouri, on July 1, 2008.

John Colomy,

Acting Manager, Small Airplane Directorate, Aircraft Certification

Service.

FR Doc. E8-15456 Filed 7-7-08; 8:45 am

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