Document ID: FAA-2010-0827-0004
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Air Tractor, Inc. Models AT-802 and AT-802A Airplanes
Posted Date: 2010-12-30T05:00Z

[Federal Register Volume 75, Number 250 (Thursday, December 30, 2010)]
[Rules and Regulations]
[Pages 82219-82228]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-32905]

=======================================================================
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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0827; Directorate Identifier 2010-CE-029-AD; 
Amendment 39-16552; AD 2010-17-18 R1]
RIN 2120-AA64

Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-
802A Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: We are revising an existing airworthiness directive (AD) for 
Air Tractor, Inc. (Air Tractor) Models AT-802 and AT-802A airplanes. 
That AD currently requires you to repetitively inspect (using the eddy 
current method) the two outboard fastener holes in both of the wing 
main spar lower caps at the center splice joint for cracks and repair 
or replace any cracked spar, and changes the safe life for certain 
serial (SN) ranges. This AD retains the actions of AD 2010-17-18 and 
reduces the applicability from all serial numbers beginning with SN-
0001 as required by the previous AD to SN-0001 through SN-0269. This AD 
was prompted by our evaluation of a comment from David Ligon, Air 
Tractor, and our determination that we should reduce the applicability 
from that already required by the previous AD. We are issuing this AD 
to detect and correct cracks in the wing main spar lower cap at the 
center splice joint, which could result in failure of the spar cap and 
lead to wing separation and loss of control of the airplane.

DATES: This AD is effective January 14, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of September 9, 
2010 (75 FR 52255, August 25, 2010).
    The Director of the Federal Register approved the incorporation by 
reference of certain other publications listed in this AD as of April 
21, 2006 (71 FR 19994, April 19, 2006).
    We must receive any comments on this AD by February 14, 2011.

ADDRESSES: You may send comments by any of the following methods:
     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-

[[Page 82220]]

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 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. You may review copies of the referenced service 
information at the FAA, Small Airplane Directorate, 901 Locust, Kansas 
City, Missouri 64106. For information on the availability of this 
material at the FAA, call 816-329-4148.

Examining the AD Docket

    You may examine the AD docket 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 AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Office (phone: 800-647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Andrew McAnaul, Aerospace Engineer, 
ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, 
Texas 78216; phone: (210) 308-3365; fax: (210) 308-3370; e-mail: 
andrew.mcanaul@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    On August 11, 2010, we issued AD 2010-17-18, amendment 39-16412 (75 
FR 52255, August 25, 2010), for all Air Tractor Models AT-802 and AT-
802A airplanes. That AD requires you to repetitively inspect (using the 
eddy current method) the two outboard fastener holes in both of the 
wing main spar lower caps at the center splice joint for cracks and 
repair or replace any cracked spar, and changes the safe life for 
certain SN ranges. That AD resulted from the FAA's evaluation of 
service information issued by Air Tractor and our determination that we 
needed to add inspections, add modifications, and change the safe life 
for certain SN ranges. We issued that AD to detect and correct cracks 
in the wing main spar lower cap at the center splice joint, which could 
result in failure of the spar cap and lead to wing separation and loss 
of control of the airplane.

Actions Since AD was Issued

    Since we issued AD 2010-17-18, we have evaluated a comment from 
David Ligon, Air Tractor, and determined that we should reduce the 
applicability from all serial numbers beginning with SN-0001 as 
required by the previous AD to SN-0001 through SN-0269. Airplane SN-
0270 and subsequent wing main spar components are life limited at 
11,700 hours time-in-service as described in Air Tractor, Inc. AT 802/
802A Airworthiness Limitations, Pages 6-i, 6-1, and 6-2, dated: 
September 16, 2009.

Relevant Service Information

    We reviewed the following service information from Snow Engineering 
Co.:
     Service Letter 80GG, revised December 21, 2005;
     Service Letter 284, dated October 4, 2009;
     Service Letter 281, dated August 1, 2009;
     Service Letter 245, dated April 25, 2005;
     Service Letter 240, dated September 30, 2004;
     Process Specification 197, page 1, revised June 
4, 2002; pages 2 through 4, dated February 23, 2001; and page 5, dated 
May 3, 2002;
     Drawing Number 20995, Sheet 3, dated November 25, 2005;
     Drawing Number 20995, Sheet 2, Rev. D., dated November 25, 
2005; and
     Drawing Number 20975, Sheet 4, Rev. A., dated January 7, 
2009.
    The service information describes procedures for the following 
actions:
     Inspection (repetitively) of the two outboard fastener 
holes in both of the wing main spar lower caps at the center splice 
joint for cracks;
     Repair or replacement of any cracked spar cap; and
     Modification option to extend the safe life limit.

FAA's Determination

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

AD Requirements

    This AD requires accomplishing the actions specified in the service 
information described previously. The AD also requires sending the 
inspection results (if cracks are found) to Andrew McAnaul, Aerospace 
Engineer, ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San 
Antonio, Texas 78216; phone: (210) 308-3365; fax: (210) 308-3370.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because the 
public has already had the opportunity to comment on the actions of 
this unsafe condition. This action only reduces the applicability from 
that already required by the previous AD. Therefore, we find that 
notice and opportunity for prior public comment are unnecessary and 
that good cause exists for making this amendment effective in less than 
30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
the docket number FAA-2010-0827 and directorate identifier 2010-CE-029-
AD at the beginning of your comments. We specifically invite comments 
on the overall regulatory, economic, environmental, and energy aspects 
of this AD. We will consider all comments received by the closing date 
and may amend this AD because 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 about this AD.

Costs of Compliance

    We estimate that this AD affects 121 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

[[Page 82221]]

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Action                     Labor cost            Parts cost                 Cost per product                  Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Eddy current inspection...........  $500 to $800........  Not Applicable......  $500 to $800.......................  $60,500 to $96,800
Spar cap replacement (two spars)..  495 work-hours x $85  $39,100 (two spars).  $81,175............................  $9,822,175
                                     per hour = $42,075.
--------------------------------------------------------------------------------------------------------------------------------------------------------

     We estimate the following costs to do any necessary center splice 
plate installation that would be required based on the results of the 
inspection. We have no way of determining the number of aircraft that 
might need this center splice plate installation:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                       Cost per
                    Action                                    Labor cost                 Parts cost    product
----------------------------------------------------------------------------------------------------------------
Center splice plate installation..............  185 work-hours x $85 per hour =              $4,300      $20,025
                                                 $15,725.
----------------------------------------------------------------------------------------------------------------

     We estimate the following costs to do any necessary extended 
splice block installation that would be required based on the results 
of the inspection. We have no way of determining the number of aircraft 
that might need this extended splice block installation:

                           On-Condition Costs
------------------------------------------------------------------------
                                                               Cost per
            Action              Labor cost     Parts cost      product
------------------------------------------------------------------------
Extended splice block             70 work-  $3,200.........       $9,150
 installation.                 hours x $85
                                per hour =
                                    $5,950
------------------------------------------------------------------------

     We estimate the following costs to do any necessary cold-work 
lower spar cap fastener holes that would be required based on the 
results of the inspection. We have no way of determining the number of 
aircraft that might need this cold-work lower spar cap fastener holes:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                       Cost per
                    Action                                    Labor cost                 Parts cost    product
----------------------------------------------------------------------------------------------------------------
Cold-work lower spar cap fastener holes.......  $1,350................................          Not       $1,350
                                                                                         Applicable
----------------------------------------------------------------------------------------------------------------

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

    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 DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends part 39 of the Federal Aviation Regulations (14 CFR part 
39) as follows:

[[Page 82222]]

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by removing airworthiness directive (AD) 
2010-17-18, amendment 39-16412 (75 FR 52255, August 25, 2010) and 
adding the following new AD:

2010-17-18 R1 Air Tractor, Inc.: Amendment 39-16552; Docket No. FAA-
2010-0827; Directorate Identifier 2010-CE-029-AD.

Effective Date

    (a) This AD is effective January 14, 2011.

Affected ADs

    (b) This AD revises AD 2010-17-18, Amendment 39-16412.

Applicability

    (c) This AD affects Air Tractor, Inc. Models AT-802 and AT-802A 
airplanes, serial numbers (SNs) -0001 through -0269, that are:
    (1) certificated in any category;
    (2) engaged in agricultural dispersal operations, including 
those airplanes that have been converted from fire fighting to 
agricultural dispersal or airplanes that convert between fire 
fighting and agricultural dispersal;
    (3) not equipped with the factory-supplied computerized fire 
gate (part number (P/N) 80540); and
    (4) not engaged in only full-time fire fighting.

Subject

    (d) Joint Aircraft System Component (JASC)/Air Transport 
Association (ATA) of America Code 57: Wings.

Unsafe Condition

    (e) This AD was prompted by our evaluation of a comment from 
David Ligon, Air Tractor, and our determination that we should 
reduce the applicability from the all serial numbers beginning with 
SN -0001 as required by the previous AD to SN -0001 through SN-0269. 
We are issuing this AD to detect and correct cracks in the wing main 
spar lower cap at the center splice joint, which could result in 
failure of the spar cap and lead to wing separation and loss of 
control of the airplane.

Compliance

    (f) Comply with this AD within the compliance times specified, 
unless already done.
    (g) To address this problem for Models AT-802 and AT-802A 
airplanes, SNs -0001 through -0091, you must do the following, 
unless already done:

              Table 1--Actions, Compliance, and Procedures
------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Eddy current inspect for  Initially inspect     Follow Snow
 cracks the center splice      upon accumulating     Engineering Co.
 joint outboard two fastener   1,700 hours time-in-  Process
 holes in both the left and    service (TIS) or      Specification
 right wing main spar lower    within the next 50    197, page
 caps.                         hours TIS after       1, revised June 4,
                               April 21, 2006 (the   2002; pages 2
                               effective date of     through 4, dated
                               AD 2006-08-09),       February 23, 2001;
                               whichever occurs      and page 5, dated
                               later, and            May 3, 2002.
                               repetitively
                               thereafter at
                               intervals not to
                               exceed 800 hours
                               TIS. If, before
                               September 9, 2010
                               (the effective date
                               of AD
                               2010[dash]17[dash]1
                               8), you installed
                               the center splice
                               plate and extended
                               8-bolt splice
                               blocks, use the
                               inspection
                               compliance times
                               found in paragraph
                               (g)(5) of this AD.
(2) If you find any cracks    Before further        Follow Snow
 as a result of any            flight after the      Engineering Co.
 inspection required in        inspection where a    Service Letter
 paragraph (g)(1) of this      crack was found.      284, dated
 AD, do the following          If, before the        October 4, 2009;
 actions:                      airplane reaches a    Snow Engineering
(i) For cracks that can be     total of 3,200        Co. Process
 repaired, repair the          hours TIS, you        Specification
 airplane by doing the         repair your           197, page
 following actions:.           airplane following    1, revised June 4,
(A) Install center splice      paragraph (g)(2)(i)   2002; pages 2
 plate, P/N 20997-2, and       of this AD, you       through 4, dated
 extended 8[dash]bolt splice   must do the eddy      February 23, 2001;
 blocks, P/N 20985-1 & -2,     current inspections   and page 5, dated
 and cold-work the lower       following the         May 3, 2002; Snow
 spar cap fastener holes;      compliance times      Engineering Co.
 and.                          found in paragraph    Drawing Number
(B) Eddy current inspect for   (g)(5) of this AD.    20995, Sheet 2,
 cracks the center splice      If, at 3,200 hours    Rev. D., dated
 joint outboard two fastener   TIS or after, you     November 25, 2005;
 holes in both the left and    repair your           and Snow
 right wing main spar lower    airplane following    Engineering Co.
 caps. This eddy current       paragraph (g)(2)(i)   Service Letter
 inspection is required as     of this AD, this      240, dated
 part of the modification      repair terminates     September 30, 2004.
 and is separate from the      the inspection
 inspections required in       requirements of
 paragraph (g)(1) of this AD.  paragraph (g)(1) of
(ii) For cracks that cannot    this AD.
 be repaired by
 incorporating the
 modification specified
 above, do the actions to
 replace the lower spar caps
 and associated parts listed
 following the procedures
 identified in paragraph
 (g)(3) of this AD.

[[Page 82223]]

 
(3) Replace the wing main     (i) Do the            Follow Snow
 spar lower caps, the web      replacement at        Engineering Co.
 plates, the center joint      whichever of the      Service Letter
 splice blocks and hardware,   following             284, dated
 and the wing attach angles    compliance times      October 4, 2009;
 and hardware, and install     occurs first:         Snow Engineering
 the steel web splice plate.  (A) Before further     Co. Service Letter
 This replacement terminates   flight when cracks    80GG,
 the repetitive inspections    are found that        revised December
 required in paragraph         cannot be repaired    21, 2005; Snow
 (g)(1) of this AD.            by incorporating      Engineering Co.
                               the modification in   Drawing Number
                               paragraph (g)(2)(i)   20975, Sheet 4,
                               of this AD; or.       Rev. A, dated
                              (B) Before or when     January 7, 2009.
                               the airplane
                               reaches the wing
                               main spar lower cap
                               safe life of a
                               total of 4,100
                               hours TIS or within
                               the next 50 hours
                               TIS after September
                               9, 2010 (the
                               effective date of
                               AD
                               2010[dash]17[dash]1
                               8), whichever
                               occurs later..
                              (ii) After this
                               replacement the new
                               spar safe life is
                               11,700 hours TIS.
                               If, before
                               September 9, 2010
                               (the effective date
                               of AD
                               2010[dash]17[dash]1
                               8), an airplane
                               main spar lower cap
                               was replaced with P/
                               N 21083-1/-2, the
                               spar safe life for
                               that P/N spar cap
                               is 8,000 hours TIS
                               until the main spar
                               lower cap is
                               replaced with P/N
                               21118-1/-2. The new
                               spar safe life for
                               P/N 21118-1/-2 is
                               11,700 hours..
                              (iii) To extend the
                               initial 4,100 hours
                               TIS safe life of
                               the wing main spar
                               lower cap to a
                               total of 8,000
                               hours TIS, you may
                               incorporate the
                               optional
                               modification
                               specified in
                               paragraph (g)(4) of
                               this AD..
(4) To extend the safe life   Modify at whichever   Follow Snow
 of the wing main spar lower   of the following      Engineering Co.
 cap to a total of 8,000       compliance times      Service Letter
 hours TIS, you may            occurs first:         284, dated
 incorporate the following    (A) Before further     October 4, 2009;
 optional modification. This   flight after any      Snow Engineering
 modification terminates the   inspection required   Co. Process
 repetitive inspections        in paragraph (g)(1)   Specification
 required in paragraph         of this AD where a    197, page
 (g)(1) of this AD, unless     crack is found. If    1, revised June 4,
 you performed the             you modify your       2002; pages 2
 modification before the       airplane before the   through 4, dated
 airplane reaches a total of   airplane reaches a    February 23, 2001;
 3,200 hours TIS to repair     total of 3,200        and page 5, dated
 cracks:                       hours TIS to repair   May 3, 2002; Snow
(i) Install center splice      cracks as required    Engineering Co.
 plate, P/N 20997-2, and       in paragraph          Drawing Number
 extended 8[dash]bolt splice   (g)(2)(i) of this     20995, Sheet 2,
 blocks, P/N 20985-1 & -2,     AD, you must do the   Rev. D., dated
 and cold-work the lower       eddy current          November 25, 2005;
 spar cap fastener holes;      inspections           and Snow
 and.                          following the         Engineering Co.
(ii) Eddy current inspect      compliance times      Service Letter
 for cracks the center         found in paragraph    240, dated
 splice joint outboard two     (g)(5) of this AD..   September 30, 2004.
 fastener holes in both the   (B) Between 3,200
 left and right wing main      hours TIS and 4,100
 spar lower caps. This eddy    hours TIS..
 current inspection is
 required as part of the
 modification and is
 separate from the
 inspections required in
 paragraph (g)(1) of this
 AD..
------------------------------------------------------------------------

     (5) If, before September 9, 2010 (the effective date of AD 
2010-17-18) or as a result of performing the repair for cracks 
following paragraph (g)(2) of this AD, you installed the center 
splice plate and extended 8-bolt splice blocks, use the following 
table for compliance times to do the eddy current inspections 
required in paragraph (g)(1) of this AD. If you find any cracks as a 
result of any inspection following the compliance times in the 
following table, you must do the replacement action in paragraph 
(g)(2)(ii) of this AD:

            Table 2--Eddy Current Inspection Compliance Times
------------------------------------------------------------------------
                                                    Repetitively inspect
                                                        thereafter at
  Condition of the airplane     Initially inspect     intervals not to
                                                           exceed
------------------------------------------------------------------------
(i) If the airplane has       When the airplane     1,200 hours TIS
 already had the center        reaches a total of    until the 8,000
 splice plate and extended     2,400 hours TIS       hours TIS spar
 8[dash]bolt splice blocks     after the             replacement time.
 installed at or after 3,200   modification or
 hours TIS but the fastener    within the next 100
 holes have not been cold      days after
 worked, at any time you may   September 9, 2010
 cold work the fastener        (the effective date
 holes to terminate the        of AD
 repetitive inspection         2010[dash]17[dash]1
 requirements of this          8), whichever
 paragraph.                    occurs later.
(ii) Before reaching 3,200    When the airplane     1,200 hours TIS.
 hours TIS, the airplane had   reaches a total of    Upon reaching 4,800
 the center splice plate and   2,400 hours TIS       hours TIS after the
 extended 8-bolt splice        after the             modification,
 blocks already installed      modification or       inspect
 but the fastener holes have   within the next 100   repetitively
 not been cold worked.         days after            thereafter at
                               September 9, 2010     intervals not to
                               (the effective date   exceed 600 hours
                               of AD                 TIS until the 8,000
                               2010[dash]17[dash]1   hours TIS spar
                               8), whichever         replacement time.
                               occurs later.

[[Page 82224]]

 
(iii) Before reaching 3,200   When the airplane     600 hours TIS until
 hours TIS, the airplane had   reaches a total of    the 8,000 hours TIS
 the center splice plate and   4,800 hours TIS       spar replacement
 extended 8-bolt splice        after the             time.
 blocks installed and the      modification or
 fastener holes have been      within the next 100
 cold worked.                  days after
                               September 9, 2010
                               (the effective date
                               of AD
                               2010[dash]17[dash]1
                               8), whichever
                               occurs later.
------------------------------------------------------------------------

    (h) To address this problem for AT-802 and AT-802A airplanes, 
SNs-0092 through -0101, you must do the following, unless already 
done:

              Table 3--Actions, Compliance, and Procedures
------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Eddy current inspect for  Initially inspect     Follow Snow
 cracks the center splice      upon accumulating     Engineering Co.
 joint outboard two fastener   1,700 hours TIS or    Service Letter
 holes in both the left and    within the next 50    284, dated
 right wing main spar lower    hours TIS after       October 4, 2009;
 caps.                         September 9, 2010     and Snow
                               (the effective date   Engineering Co.
                               of AD 2010-17-18),    Process
                               whichever occurs      Specification
                               later, and            197, page
                               repetitively          1, revised June 4,
                               thereafter at         2002; pages 2
                               intervals not to      through 4, dated
                               exceed 800 hours      February 23, 2001;
                               TIS. If the center    and page 5, dated
                               splice plate, P/N     May 3, 2002.
                               20994-2, is
                               installed as
                               specified in
                               paragraph (h)(4) of
                               this AD, do the
                               repetitive
                               inspections at
                               intervals not to
                               exceed 2,000 hours
                               TIS.
(2) If you find any cracks    Before further        Follow Snow
 as a result of any            flight after the      Engineering Co.
 inspection required by        inspection where a    Service Letter
 paragraph (h)(1) of this      crack was found.      284, dated
 AD, do the following          This repair           October 4, 2009;
 actions. This repair          modification in       and Snow
 modification terminates the   paragraph (h)(2)(i)   Engineering Co.
 repetitive inspections        of this AD extends    Process
 required in paragraph         the safe life of      Specification
 (h)(1) of this AD:            the wing main spar    197, page
(i) For cracks that can be     lower cap to a        1, revised June 4,
 repaired, repair the          total of 8,000        2002; pages 2
 airplane by doing the         hours TIS.            through 4, dated
 following actions:.                                 February 23, 2001;
(A) Install the 9-bolt                               and page 5, dated
 splice blocks and cold-work                         May 3, 2002, Snow
 the lower spar cap fastener                         Engineering Co.
 holes;.                                             Service Letter
(B) Eddy current inspect for                         281, dated
 cracks the center splice                            August 1, 2009; and
 joint outboard two fastener                         Snow Engineering
 holes in both the left and                          Co. Drawing Number
 right wing main spar lower                          20995, Sheet 3,
 caps. This eddy current                             dated November 25,
 inspection is required as                           2005.
 part of the repair and is
 separate from the
 inspections required in
 paragraph (h)(1) of this
 AD; and.
(C) Install the center
 splice plate, P/N 20994-2,
 per paragraph (h)(4) if not
 already installed..
(ii) For cracks that cannot
 be repaired by doing the
 actions in paragraph
 (h)(2)(i) of this AD,
 replace the lower spar caps
 and associated parts listed
 following the procedures
 identified in paragraph
 (h)(3) of this AD..
(3) Replace the wing main      (i) Do the           Follow Snow
 spar lower caps, the web      replacement at        Engineering Co.
 plates, the center joint      whichever of the      Service Letter
 splice blocks and hardware,   following             284, dated
 and the wing attach angles    compliance times      October 4, 2009;
 and hardware, and install     occurs first:         Snow Engineering
 the steel web splice plate.  (A) Before further     Co. Service Letter
 This replacement terminates   flight when cracks    80GG,
 the repetitive inspections    are found that        revised December
 required in paragraph         cannot be repaired    21, 2005; Snow
 (h)(1) of this AD.            by incorporating      Engineering Co.
                               the modification in   Drawing Number
                               paragraph (h)(2)(i)   20975, Sheet 4,
                               of this AD; or.       Rev. A, dated
                              (B) Before or when     January 7, 2009.
                               the airplane
                               reaches the wing
                               main spar lower cap
                               safe life of a
                               total of 4,100
                               hours TIS or within
                               the next 50 hours
                               TIS after September
                               9, 2010 (the
                               effective date of
                               AD 2010-17-18),
                               whichever occurs
                               later..
                              (ii) To extend the
                               initial 4,100 hours
                               TIS safe life of
                               the wing main spar
                               lower cap to a
                               total of 8,000
                               hours TIS, you may
                               incorporate the
                               optional
                               modification
                               specified in
                               paragraph (h)(4) of
                               this AD..
                              (iii)After
                               replacement of the
                               old spar with the
                               new lower spar cap,
                               P/N 21118-1/-2, the
                               new spar safe life
                               is 11,700 hours
                               TIS..

[[Page 82225]]

 
(4) To extend the safe life   Before the airplane   Follow Snow
 of the wing main spar lower   reaches a total of    Engineering Co.
 cap to a total of 8,000       4,100 hours TIS.      Service Letter
 hours TIS, you may            After installation    284, dated
 incorporate the following     of the center         October 4, 2009;
 optional modification:        splice plate, P/N     Snow Engineering
(i) Install center splice      20994-2, do the       Co. Process
 plate, P/N 20994-2, if not    repetitive            Specification
 already installed as part     inspections           197, page
 of a repair, and cold-work    required in           1, revised June 4,
 the lower spar cap fastener   paragraph (h)(1) at   2002; pages 2
 holes; and.                   intervals not to      through 4, dated
(ii) Eddy current inspect      exceed 2,000 hours    February 23, 2001;
 for cracks the center         TIS. If as of         and page 5, dated
 splice joint outboard two     September 9, 2010     May 3, 2002; Snow
 fastener holes in both the    (the effective date   Engineering Co.
 left and right wing main      of AD 2010-17-18)     Drawing Number
 spar lower caps. This eddy    you have already      20975, Sheet 4,
 current inspection is         exceeded the 4,100    Rev. A., dated
 required as part of the       hours TIS threshold   January 7, 2009;
 modification and is           for extending the     and Snow
 separate from the             safe life to 8,000    Engineering Co.
 inspections required in       hours TIS, you may    Service Letter
 paragraph (h)(1) of this      be eligible for an    245, dated
 AD..                          alternative method    April 25, 2005.
                               of compliance
                               following paragraph
                               (n) in this AD.
(5) If you find any cracks    Before further        Follow Snow
 as a result of any            flight after the      Engineering Co.
 repetitive inspection         inspection where a    Service Letter
 required by paragraph         crack was found.      284, dated
 (h)(4) of this AD, do the                           October 4, 2009;
 following actions. This                             and Snow
 repair modification                                 Engineering Co.
 terminates the repetitive                           Process
 inspections required in                             Specification
 paragraph (h)(4) of this                            197, page
 AD:                                                 1, revised June 4,
(i) For cracks that can be                           2002; pages 2
 repaired, repair the                                through 4, dated
 airplane by doing the                               February 23, 2001;
 following actions:.                                 and page 5, dated
(A) Install the 9-bolt                               May 3, 2002, Snow
 splice blocks and cold-work                         Engineering Co.
 the lower spar cap fastener                         Service Letter
 holes; and.                                         281, dated
(B) Eddy current inspect for                         August 1, 2009; and
 cracks the center splice                            Snow Engineering
 joint outboard two fastener                         Co. Drawing Number
 holes in both the left and                          20995, Sheet 3,
 right wing main spar lower                          dated November 25,
 caps. This eddy current                             2005.
 inspection is required as
 part of the repair and is
 separate from the
 inspections required in
 paragraph (h)(1) of this
 AD..
(ii) For cracks that cannot
 be repaired by doing the
 actions in paragraph
 (h)(5)(i) of this AD,
 replace the lower spar caps
 and associated parts listed
 following the procedures
 identified in paragraph
 (h)(3) of this AD..
------------------------------------------------------------------------

     (i) To address this problem for AT-802 and AT-802A airplanes, 
SNs -0102 through -0178, you must do the following, unless already 
done:

              Table 4--Actions, Compliance, and Procedures
------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Do an initial eddy        Before the airplane   Follow Snow
 current inspection for        reaches a total of    Engineering Co.
 cracks of the center splice   5,500 hours TIS or    Process
 joint outboard two fastener   within the next 50    Specification
 holes in both the left and    hours TIS after       197, page
 right wing main spar lower    September 9, 2010     1, revised June 4,
 caps. After this initial      (the effective date   2002; pages 2
 inspection, you may do the    of AD                 through 4, dated
 optional cold-working of      2010[dash]17[dash]1   February 23, 2001;
 the lower spar cap fastener   8), whichever         and page 5, dated
 holes to increase the hours   occurs later.         May 3, 2002; Snow
 TIS between repetitive                              Engineering Co.
 inspections required in                             Service Letter
 paragraph (i)(2) of this AD.                        245, dated
                                                     April 25, 2005; and
                                                     Snow Engineering
                                                     Co. Service Letter
                                                     284, dated
                                                     October 4, 2009.
(2) Repetitively eddy          (i) For fastener     Follow Snow
 current inspect for cracks    holes that are cold-  Engineering Co.
 the center splice joint       worked: After the     Process
 outboard two fastener holes   initial inspection,   Specification
 in both the left and right    repetitively          197, page
 wing main spar lower caps.    thereafter inspect    1, revised June 4,
                               at intervals not to   2002; pages 2
                               exceed 2,200 hours    through 4, dated
                               TIS.                  February 23, 2001;
                              (ii) For fastener      and page 5, dated
                               holes not cold-       May 3, 2002; Snow
                               worked: After the     Engineering Co.
                               initial inspection,   Service Letter
                               repetitively          284, dated
                               thereafter inspect    October 4, 2009;
                               at intervals not to   and (optional) Snow
                               exceed 1,100 hours    Engineering Co.
                               TIS.                  Service Letter
                                                     245, dated
                                                     April 25, 2005.

[[Page 82226]]

 
(3) If you find any cracks    Before further        Follow Snow
 as a result of any            flight after the      Engineering Co.
 inspection required by        inspection where a    Service Letter
 paragraphs (i)(1) and         crack was found.      281, dated
 (i)(2) of this AD, do the                           August 1, 2009; and
 following actions. This                             Snow Engineering
 modification terminates the                         Co. Drawing Number
 repetitive inspections                              20995, Sheet 3,
 required in paragraph                               dated November 25,
 (i)(1) and (i)(2) of this                           2005.
 AD:
(i) For cracks that can be
 repaired, repair the
 airplane by doing the
 following actions:.
(A) Install the 9-bolt
 splice blocks and cold-work
 the lower spar cap fastener
 holes; and.
(B) Eddy current inspect for
 cracks the center splice
 joint outboard two fastener
 holes in both the left and
 right wing main spar lower
 caps. This eddy current
 inspection is required as
 part of the repair and is
 separate from the
 inspections required in
 paragraphs (i)(1) and
 (i)(2) of this AD..
(ii) For cracks that cannot
 be repaired by doing the
 actions in paragraph
 (i)(3)(i) of this AD,
 replace the lower spar caps
 and associated parts listed
 following the procedures in
 paragraph (i)(4) of this
 AD..
(4) Replace the wing main     (i) Do the            Follow Snow
 spar lower caps, the web      replacement at        Engineering Co.
 plates, the center joint      whichever of the      Service Letter
 splice blocks and hardware,   following             284, dated
 and the wing attach angles    compliance times      October 4, 2009;
 and hardware, and install     occurs first:         Snow Engineering
 the steel web splice plate.  (A) Before further     Co. Service Letter
 This replacement terminates   flight when cracks    80GG,
 the repetitive inspections    are found that        revised December
 required in paragraphs        cannot be repaired    21, 2005; Snow
 (i)(1) and (i)(2) of this     by incorporating      Engineering Co.
 AD.                           the repair in         Drawing Number
                               paragraph (i)(3)(i)   20975, Sheet 4,
                               of this AD; or.       Rev. A, dated
                              (B) Before or when     January 7, 2009.
                               the airplane
                               reaches the wing
                               main spar lower cap
                               safe life of a
                               total of 8,000
                               hours TIS or within
                               the next 50 hours
                               TIS after September
                               9, 2010 (the
                               effective date of
                               AD
                               2010[dash]17[dash]1
                               8), whichever
                               occurs later..
                              (ii) After this
                               replacement the new
                               spar safe life is
                               11,700 hours TIS..
------------------------------------------------------------------------

    (j) To address this problem for AT-802 and AT-802A airplanes, 
SNs -0179 through -0269, you must do the following, unless already 
done:

              Table 5--Actions, Compliance, and Procedures
------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
Replace the wing main spar    By the 8,000 hours    Follow Snow
 lower caps, the web plates,   TIS safe-life or      Engineering Co.
 the center joint splice       within the next 50    Service Letter
 blocks and hardware, and      hours TIS after       284, dated
 the wing attach angles and    September 9, 2010     October 4, 2009;
 hardware, and install the     (the effective date   Snow Engineering
 steel web splice plate.       of AD                 Co. Service Letter
                               2010[dash]17[dash]1   80GG,
                               8), whichever         revised December
                               occurs later. After   21, 2005; Snow
                               this replacement      Engineering Co.
                               the subsequent new    Drawing Number
                               spar safe life is     20975, Sheet 4,
                               11,700 hours TIS.     Rev. A, dated
                                                     January 7, 2009.
------------------------------------------------------------------------

     (k) Report any crack from any inspection required in paragraphs 
(g), (h), or (i) of this AD within 10 days after the cracks are 
found on the form in Figure 1 of this AD.
    (1) Send your report to Andrew McAnaul, Aerospace Engineer, ASW-
150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, 
Texas 78216; phone: (210) 308-3365; fax: (210) 308-3370.
    (2) The Office of Management and Budget (OMB) approved the 
information collection requirements contained in this regulation 
under the provisions of the Paperwork Reduction Act and assigned OMB 
Control Number 2120-0056.

Special Permit Flight

    (l) Under 14 CFR 39.23, we are allowing special flight permits 
for the purpose of compliance with this AD under the following 
conditions:
    (1) Only operate in day visual flight rules (VFR).
    (2) Ensure that the hopper is empty.
    (3) Limit airspeed to 135 miles per hour (mph) indicated 
airspeed (IAS).
    (4) Avoid any unnecessary g-forces.
    (5) Avoid areas of turbulence.
    (6) Plan the flight to follow the most direct route.
BILLING CODE 4910-13-P

[[Page 82227]]

[GRAPHIC] [TIFF OMITTED] TR30DE10.023

BILLING CODE 4910-13-C

[[Page 82228]]

Paperwork Reduction Act Burden Statement

    (m) A federal agency may not conduct or sponsor, and a person is 
not required to respond to, nor shall a person be subject to a 
penalty for failure to comply with a collection of information 
subject to the requirements of the Paperwork Reduction Act unless 
that collection of information displays a current valid OMB Control 
Number. The OMB Control Number for this information collection is 
2120-0056. Public reporting for this collection of information is 
estimated to be approximately 5 minutes per response, including the 
time for reviewing instructions, completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Comments concerning the accuracy of this 
burden and suggestions for reducing the burden should be directed to 
the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn: 
Information Collection Clearance Officer, AES-200.

Alternative Methods of Compliance (AMOCs)

    (n)(1) 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. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD.
    (2) Before using any approved AMOC, notify your Principal 
Maintenance Inspector or Principal Avionics Inspector, as 
appropriate, or lacking a principal inspector, your local Flight 
Standards District Office.
    (3) AMOCs approved for AD 2010-17-18 are approved as AMOCs for 
this AD.

Related Information

    (o) For more information about this AD, contact Andrew McAnaul, 
Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100 Reunion Place, 
Suite 650, San Antonio, Texas 78216; phone: (210) 308-3365; fax: 
(210) 308-3370; e-mail: andrew.mcanaul@faa.gov.

Material Incorporated by Reference

    (p)(1) You must use the service information contained in table 6 
of this AD to do the actions required by this AD, unless the AD 
specifies otherwise. The Director of the Federal Register previously 
approved the incorporation by reference of the service information 
contained in table 6 of this AD on the date specified in the column 
``Incorporation by Reference Approval Date'' of Table 6.

                                   Table 6--Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
                                                                                      Incorporation by reference
              Document                      Revision                  Date                  approval date
----------------------------------------------------------------------------------------------------------------
(i) Snow Engineering Co. Service     Not Applicable........  December 21, 2005.....  September 9, 2010 (75 FR
 Letter 80GG.                                                                52255, August 25, 2010).
(ii) Snow Engineering Co. Service    Not Applicable........  October 4, 2009.......  September 9, 2010 (75 FR
 Letter 284.                                                                 52255, August 25, 2010).
(iii) Snow Engineering Co. Service   Not Applicable........  August 1, 2009........  September 9, 2010 (75 FR
 Letter 281.                                                                 52255, August 25, 2010).
(iv) Snow Engineering Co. Service    Not Applicable........  April 25, 2005........  September 9, 2010 (75 FR
 Letter 245.                                                                 52255, August 25, 2010).
(v) Snow Engineering Co. Service     Not Applicable........  September 30, 2004....  April 21, 2006 (71 FR
 Letter 240.                                                                 19994, April 19, 2006).
(vi) Snow Engineering Co. Process    ......................  ......................  April 21, 2006 (71 FR
 Specification 197:                                                          19994, April 19, 2006).
    page 1.........................  Not Applicable........  June 4, 2002..........  April 21, 2006 (71 FR
                                                                                      19994, April 19, 2006).
    pages 2 through 4..............  Not Applicable........  February 23, 2001.....  April 21, 2006 (71 FR
                                                                                      19994, April 19, 2006).
    page 5.........................  Not Applicable........  May 3, 2002...........  April 21, 2006 (71 FR
                                                                                      19994, April 19, 2006).
(vii) Snow Engineering Co. Drawing   ......................  ......................  September 9, 2010 (75 FR
 Number 20995:                                                                        52255, August 25, 2010).
    Sheet 2........................  Rev. D................  November 25, 2005.....  September 9, 2010 (75 FR
                                                                                      52255, August 25, 2010).
    Sheet 3........................  Not Applicable........  November 25, 2005.....  September 9, 2010 (75 FR
                                                                                      52255, August 25, 2010).
(viii) Snow Engineering Co. Drawing  Rev. A................  January 7, 2009.......  September 9, 2010 (75 FR
 Number 20975, Sheet 4.                                                               52255, August 25, 2010).
----------------------------------------------------------------------------------------------------------------

     (2) For service information identified 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: www.airtractor.com.
    (3) You may review copies of the service information at the FAA, 
Small Airplane Directorate, 901 Locust, Kansas City, Missouri 64106. 
For information on the availability of this material at the FAA, 
call 816-329-4148.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at an NARA facility, 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 December 16, 2010.
William J. Timberlake,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-32905 Filed 12-29-10; 8:45 am]
BILLING CODE 4910-13-P