
[Federal Register: March 3, 2008 (Volume 73, Number 42)]
[Proposed Rules]               
[Page 11369-11371]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr03mr08-18]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0247; Directorate Identifier 2008-CE-003-AD]
RIN 2120-AA64

 
Airworthiness Directives; Air Tractor, Inc. AT-200, AT-300, AT-
400, AT-500, AT-600, 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) 2002-25-
09, which applies to certain Air Tractor, Inc. (Air Tractor) AT-250, 
AT-300, AT-400, and AT-500 series airplanes. AD 2002-25-09 currently 
requires you to install an overturn skid plate in the cockpit area. 
Since we issued AD 2002-25-09, we received a report of the bolts 
attaching the forward end of the original design overturn skid plate to 
the airframe breaking in an overturn accident. This allowed the skid 
plate to rotate around the rear attach point and the forward end of the 
plate to enter the cockpit area. Consequently, this proposed AD would 
require the installation of a modified skid plate kit or modification 
to skid plate kits that are already installed, including those already 
installed on AT-402B, AT-502B, AT-602, and AT-802A series airplanes 
during production. 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 May 2, 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.

FOR FURTHER INFORMATION CONTACT: Andy McAnaul, Aerospace Engineer, ASW-
150, FAA San Antonio MIDO-43, 10100 Reunion Place, Suite 650, San 
Antonio, Texas 78216, phone: (210) 308-3365, fax: (210) 308-3370.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments

[[Page 11370]]

regarding this proposed AD. Send your comments to an address listed 
under the ADDRESSES section. Include the docket number, ``FAA-2008-
0247; Directorate Identifier 2008-CE-003-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

    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 currently requires 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-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. 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 November 7, 2007.
    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 2002-25-09 with a new AD that would require:
     For airplanes with an installation previously accomplished 
per the original AD: incorporating modification kit part-number (P/N) 
11411-1-501 composed of the heavier attaching hardware; and
     For airplanes without the overturn skid plate installed: 
incorporating kit P/N 11411-1-502, which incorporates the skid plate 
and the heavier attaching hardware.
    The airplanes below include all of the airplanes from the original 
AD, which did not have the factory-installed skid plate:

------------------------------------------------------------------------
                  Models                             Serial Nos.
------------------------------------------------------------------------
AT-250, AT-300, AT-301, AT-302, AT-400, AT- -0001 through -0829.
 400A, AT-401, AT-401A, AT-402, and AT-
 402A.
AT-501, AT-502, AT-502A...................  -0001 through -0147.
------------------------------------------------------------------------

    The airplanes in the table below have been added to this proposed 
AD. They have a factory-installed skid plate and require installation 
of the overturn skid plate modification kit part number 1411-1-501:

------------------------------------------------------------------------
                  Models                             Serial Nos.
------------------------------------------------------------------------
AT-250, AT-300, AT-301, AT-302, AT-400, AT- -0830 through -1196.
 400A, AT-401, AT-401A, AT-402, AT-402A
 and AT-402B.
AT-501, AT-502, AT-502A, and AT-502B......  -0148 through -2620.
AT-602....................................  -0337 through -1153.
AT-802A...................................  -0003 through -0282.
------------------------------------------------------------------------

Costs of Compliance

    We estimate that this proposed AD would affect 2,026 airplanes in 
the U.S. registry.
    We presume that all airplanes in the U.S. fleet have a 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 in determining the 
total cost on U.S. operators. 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         $409,252
----------------------------------------------------------------------------------------------------------------

    The proposed AD includes a requirement for those few, if any, 
airplanes that have not operated past the compliance time of AD 2002-
25-09.

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:

[[Page 11371]]

    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 removing Airworthiness Directive 
(AD) 2002-25-09, Amendment 39-12985 (67 FR 78156, December 23, 2002), 
and adding the following new AD:

Air Tractor, Inc.: Docket No. FAA-2008-0247; Directorate Identifier 
2008-CE-003-AD.

Comments Due Date

    (a) We must receive comments on this airworthiness directive 
(AD) action by May 2, 2008.

Affected ADs

    (b) This AD supersedes AD 2002-25-09, Amendment 39-12985.

Applicability

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

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

Unsafe Condition

    (d) Since we issued AD 2002-25-09, we received a report of the 
bolts that attach the forward end of the original design overturn 
skid plate to the airframe breaking in an overturn accident. This 
allowed the skid plate to rotate around the rear attach point, and 
the forward end of the plate to enter the cockpit area. 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.

Compliance

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

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

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 Place, Suite 650, San Antonio, Texas 78216, phone: (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. 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 February 26, 2008.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-4005 Filed 2-29-08; 8:45 am]

BILLING CODE 4910-13-P
