Document ID: FAA-2008-1120-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Air Tractor, Inc. Models AT-200, AT- 300, AT-400, AT-500, AT-600, and AT-800 Series Airplanes
Posted Date: 2008-10-23T04:00Z

[Federal Register: October 23, 2008 (Volume 73, Number 206)]
[Proposed Rules]               
[Page 63096-63098]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23oc08-20]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1120; Directorate Identifier 2008-CE-064-AD]
RIN 2120-AA64

 
Airworthiness Directives; Air Tractor, Inc. Models AT-200, AT-
300, AT-400, AT-500, AT-600, and AT-800 Series Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede Airworthiness Directive (AD) 2008-11-
17, which applies to certain Air Tractor, Inc. Models AT-200, AT-300, 
AT-400, AT-500, AT-600, and AT-800 series airplanes. AD 2008-11-17 
currently requires you to install an overturn skid plate kit or a 
modification to the overturn skid plate already installed. Since we 
issued AD 2008-11-17, the manufacturer has notified us that Model AT-
401B airplanes also require a modification to the overturn skid plate. 
Consequently, this proposed AD would retain the actions of AD 2008-11-
17 and add the requirement to modify the overturn skid plate installed 
on Model AT-401B airplanes. We are proposing this AD to prevent the 
front and rear connections of the overturn skid plate to the airplane 
from breaking, which could allow foreign debris to enter the cockpit 
during an airplane overturn. This condition, if not corrected, could 
lead to pilot injury.

DATES: We must receive comments on this proposed AD by November 24, 
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; fax: (940) 564-5612; e-mail: airmail@airtractor.com; Internet: 
http://www.airtractor.com.

FOR FURTHER INFORMATION CONTACT: Andy McAnaul, Aerospace Engineer, ASW-
150, FAA San Antonio MIDO-43, 10100 Reunion Pl., Ste. 650, San Antonio, 
Texas 78216; telephone: (210) 308-3365; fax: (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-
2008-1120; Directorate Identifier 2008-CE-064-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

[[Page 63097]]

substantive verbal contact we receive concerning this proposed AD.

Discussion

    Reports of foreign material entering the cabin area during an 
overturn skid on Air Tractor, Inc. (Air Tractor) AT-301 and AT-401 
series airplanes caused us to issue AD 2002-25-09, Amendment 39-12985 
(67 FR 78156, December 23, 2002). AD 2002-25-09 required you to install 
overturn skid plate, part number (P/N) 11411-1-500 or an FAA-approved 
equivalent P/N. The manufacturer incorporated skid plates in some 
production models including Models AT-401B, AT-402B, AT-502B, AT-602, 
and AT-802A airplanes.
    Since we issued AD 2002-25-09, we received a report of the bolts 
breaking in an overturn accident where they attach the forward end of 
the original design overturn skid plate to the airframe. This allowed 
the skid plate to rotate around the rear attach point and the forward 
end of the plate to enter the cockpit area. This report caused us to 
issue AD 2008-11-17, Amendment 39-15540 (73 FR 31351, June 2, 2008). AD 
2008-11-17 currently retains the actions of AD 2002-25-09 and requires 
you to install a modification kit if certain overturn skid plates are 
already installed.
    Since we issued AD 2008-11-17, the manufacturer has notified us 
that Model AT-401B airplanes also require a modification to the 
overturn skid plane. Consequently, this proposed AD would retain the 
actions of AD 2008-11-17 and add the requirement to modify the overturn 
skid plate installed on Model AT-401B airplanes.
    We are proposing this AD to prevent the front and rear connections 
of the overturn skid plate to the airplane from breaking, which could 
allow foreign debris to enter the cockpit during an airplane overturn. 
This condition, if not corrected, could lead to pilot injury.

Relevant Service Information

    We have reviewed Snow Engineering Company Service Letter 
97, Revised September 19, 2008.
    The service information describes procedures for:
     Modifying the overturn skid plate by enlarging the 
mounting holes and replacing existing clamps and hardware on airplanes 
with the overturn skid plate installed; and
     Installing the overturn skid plate for airplanes that do 
not have the overturn skid plate currently installed.

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 supersede AD 2008-11-17 with a new AD that would retain the 
actions of AD 2008-11-17 and add the requirement to modify the overturn 
skid plate installed on Model AT-401B airplanes. This proposed AD would 
require you to use the service information described previously to 
perform these actions.

Costs of Compliance

    We estimate that this proposed AD would affect 1,309 airplanes in 
the U.S. registry.
    In determining the total cost on U.S. operators, we presume all 
airplanes in the U.S. fleet have an overturn skid plate installed (as 
required by AD 2002-25-09) and the only cost is to incorporate the 
modification kit P/N 11411-1-501. We estimate the following costs to do 
the proposed modification of installing the overturn skid plate 
modification kit P/N 11411-1-501 to those planes that currently have 
the overturn skid plate installed:

----------------------------------------------------------------------------------------------------------------
                                                                                 Total cost per   Total cost on
                          Labor cost                              Parts cost        airplane      U.S. operators
----------------------------------------------------------------------------------------------------------------
2 work-hours x $80 per hour = $160...........................             $42             $202         $264,418
----------------------------------------------------------------------------------------------------------------

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, 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.

[[Page 63098]]

Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by removing Airworthiness Directive 
(AD) 2008-11-17, Amendment 39-15540 (73 FR 31351, June 2, 2008), and 
adding the following new AD:

Air Tractor, Inc.: Docket No. FAA-2008-1120; Directorate Identifier 
2008-CE-064-AD.

Comments Due Date

    (a) We must receive comments on this airworthiness directive 
(AD) action by November 24, 2008.

Affected ADs

    (b) This AD supersedes AD 2008-11-17, Amendment 39-15540.

Applicability

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

------------------------------------------------------------------------
          Group 1 models                         Serial Nos.
------------------------------------------------------------------------
AT-250, AT-300, AT-301, AT-302, AT- -0001 through -1196.
 400, AT-400A, AT-401, AT-401A, AT-
 402, AT-402A, and AT-402B.
AT-501, AT-502, AT-502A, and AT-    -0001 through -2620.
 502B.
AT-602............................  -0337 through -1153.
AT-802A...........................  -0003 through -0282.
------------------------------------------------------------------------

           Group 2 model                         Serial Nos.
------------------------------------------------------------------------
AT-401B...........................  -0952 through -1196.
------------------------------------------------------------------------

Unsafe Condition

    (d) Since we issued AD 2008-11-17, the manufacturer has notified 
us that Model AT-401B airplanes also require a modification to the 
overturn skid plate. Consequently, this proposed AD retains the 
actions of AD 2008-11-17 and adds the requirement to modify the 
overturn skid plate installed on Model AT-401B airplanes. We are 
issuing this AD to prevent the front and rear connections of the 
overturn skid plate to the airplane from breaking, which could allow 
foreign debris to enter the cockpit during an airplane overturn. 
This condition, if not corrected, could lead to pilot injury.

Compliance

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

------------------------------------------------------------------------
             Actions                  Compliance          Procedures
------------------------------------------------------------------------
(1) For Group 1 airplanes: If     Within the next     Follow Snow
 overturn skid plate part number   180 days after      Engineering Co.
 (P/N) 11411-1-500 or an FAA-      July 7, 2008 (the   Service Letter
 approved equivalent P/N is        effective date of   97,
 already installed then install    AD 2008-11-17).     revised November
 P/N 11411-1-501 modification                          7, 2007; or Snow
 kit.                                                  Engineering Co.
                                                       Service Letter
                                                       97,
                                                       revised September
                                                       19, 2008.
(2) For Group 1 airplanes: If     Within the next     Follow Snow
 there is no overturn skid plate   180 days after      Engineering Co.
 installed, then install           July 7, 2008 (the   Service Letter
 overturn skid plate kit P/N       effective date of   97,
 11411-1-502 or an FAA-approved    AD 2008-11-17).     revised November
 equivalent part number.                               7, 2007; or Snow
                                                       Engineering Co.
                                                       Service Letter
                                                       97,
                                                       revised September
                                                       19, 2008.
(3) For Group 2 airplanes:        Within the next     Follow Snow
 Install P/N 11411-1-501           180 days after      Engineering Co.
 modification kit.                 the effective       Service Letter
                                   date of this AD.    97,
                                                       revised September
                                                       19, 2008.
------------------------------------------------------------------------

Alternative Methods of Compliance (AMOCs)

    (f) The Manager, Fort Worth Airplane 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: Andy 
McAnaul, Aerospace Engineer, ASW-150, FAA San Antonio MIDO-43, 10100 
Reunion Pl., Ste. 650, San Antonio, Texas 78216; telephone: (210) 
308-3365; fax: (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; fax: (940) 564-5612; e-mail: 
airmail@airtractor.com; Internet: http://www.airtractor.com. 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 October 14, 2008.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-25286 Filed 10-22-08; 8:45 am]

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