Document ID: FAA-2010-0827-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Air Tractor, Inc. Models AT-802 and AT-802A Airplanes
Posted Date: 2010-08-25T04:00Z

[Federal Register: August 25, 2010 (Volume 75, Number 164)]
[Rules and Regulations]               
[Page 52255-52263]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25au10-11]                         

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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 39-16412; AD 2010-17-18]
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.

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SUMMARY: We are adopting a new airworthiness directive (AD) to 
supersede AD 2010-13-08, which applies to all Air Tractor, Inc. (Air 
Tractor) Models AT-802 and AT-802A airplanes. AD 2010-13-08 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 cap. Since we issued 2010-13-08, we evaluated service 
information issued by Air Tractor and determined we need to add 
inspections, add modifications, and change the safe life for certain 
serial number (SN) ranges. Consequently, this AD would retain the 
actions of AD 2010-13-08 and would add inspections, add modifications, 
and change the safe life for certain SN ranges. 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 becomes effective on September 9, 2010.
    On September 9, 2010, the Director of the Federal Register approved 
the incorporation by reference of Snow Engineering Co. Service Letter 
80GG, revised December 21, 2005; Snow Engineering Co. Service 
Letter 284, dated October 4, 2009; Snow Engineering Co. 
Service Letter 281, dated August 1, 2009; Snow Engineering Co. 
Service Letter 245, dated April 25, 2005; Snow Engineering Co. 
Drawing Number 20995, Sheet 3, dated November 25, 2005; Snow 
Engineering Co. Drawing Number 20995, Sheet 2, Rev. D., dated November 
25, 2005; and Snow Engineering Co. Drawing Number 20975, Sheet 4, Rev. 
A., dated January 7, 2009, listed in this AD.
    As of April 21, 2006 (71 FR 19994, April 19, 2006), the Director of 
the Federal Register approved the incorporation by reference of Snow 
Engineering Co. Service Letter 240, dated September 30, 2004; 
and Snow Engineering Co. Process Specification 197, page 1, 
revised June 4, 2002; pages 2 through 4, dated February 23, 2001; and 
page 5, dated May 3, 2002, listed in this AD.
    We must receive any comments on this AD by October 12, 2010.

ADDRESSES: Use one of the following addresses to comment on this 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.
    To get the 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.
    To view the comments to this AD, go to http://www.regulations.gov. 
The docket number is FAA-2010-0827; Directorate Identifier 2010-CE-029-
AD.

FOR FURTHER INFORMATION CONTACT: Andrew McAnaul, Aerospace Engineer, 
ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, 
Texas 78216; telephone: (210) 308-3365; facsimile: (210) 308-3370.

SUPPLEMENTARY INFORMATION:

Discussion

    Since 2000, we have issued several ADs related to the wing spar 
inspection and safe life on Air Tractor AT-400, AT-500, AT-600, and AT-
800 series airplanes.
    In 2001, we issued AD 2001-10-04, Amendment 39-12230 (66 FR 27014, 
May 16, 2001) to lower the safe life for the wing lower spar cap on Air 
Tractor AT-400, AT-500, and AT-800 series airplanes. This AD allowed 
for inspection (using eddy current methods) of the wing lower spar cap 
for airplanes that were at or over the lower safe life and for which 
parts were not available. Later that same year, we revised that AD to 
remove AT-800 series airplanes from the applicability that were 
equipped with the factory-supplied computerized fire gate (part number 
80540) and engaged in full-time firefighting.
    In 2002, we issued AD 2002-11-05, Amendment 39-12766 (67 FR 37967, 
May 31, 2002) that retained the actions for the AT-802 series airplanes 
and further reduced the safe life for certain AT-400 series airplanes 
and certain AT-500 series airplanes that either incorporate or have 
incorporated Marburger winglets.
    After receiving reports of fatigue cracking found on three Model 
AT-802A airplanes that were below the reduced safe life established in 
AD 2001-10-04, we issued AD 2006-08-09, Amendment 39-14565 (71 FR 
27794, May 12, 2006). AD 2006-08-09 required repetitively inspecting 
the two outboard fastener holes in both of the wing main spar lower 
caps at the center splice joint for cracks and repairing or replacing 
any cracked spar cap.
    After issuing AD 2006-08-09, we determined the need to clarify the 
affected SN applicability. Models AT-

[[Page 52256]]

802 and AT-802A share a common SN range. Sometimes service information 
listed only one of the models with a starting or ending SN within a SN 
range, depending on which model was produced with that specific SN, 
even though the service information applied to both models. We 
superseded AD 2006-08-09 and issued AD 2010-13-08, Amendment 39-16339 
(75 FR 35616, June 23, 2010) to retain the actions from AD 2006-08-09, 
clarify serial number applicability, and add an option of modifying the 
wing main spar lower caps to extend the safe life limit.
    After completing fatigue analysis on Models AT-802 and AT-802A 
airplanes, Air Tractor issued service information that adds 
inspections, adds modifications, and changes the safe life for certain 
SN ranges. Since we issued 2010-13-08, we evaluated this new service 
information and determined the need to add inspections, add 
modifications, and change the safe life for certain SN ranges.
    This condition, if not corrected, could result in failure of the 
spar cap and lead to wing separation and loss of control of the 
airplane.

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 and Requirements of This AD

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

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we determined that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists for making this amendment effective in fewer than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and an opportunity for 
public comment. We invite you to send any written relevant data, views, 
or arguments regarding this AD. Send your comments to an address listed 
under the ADDRESSES section. Include the docket number ``FAA-2010-0827; 
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 the AD. We will consider 
all comments received by the closing date and may amend the 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 AD.

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.

[[Page 52257]]

Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA) 
establishes as a principle of regulatory issuance that agencies shall 
endeavor, consistent with the objective of the rule and of applicable 
statutes, to fit regulatory and informational requirements to the scale 
of the businesses, organizations, and governmental jurisdictions 
subject to regulation.
    To achieve that principle, the RFA requires agencies to solicit and 
consider flexible regulatory proposals and to explain the rationale for 
their actions. The RFA covers a wide-range of small entities, including 
small businesses, not-for-profit organizations, and small governmental 
jurisdictions.
    Agencies must perform a review to determine whether a proposed or 
final rule will have a significant economic impact on a substantial 
number of small entities. In accordance with Section 608 of the 
Regulatory Flexibility Act, an agency head may waive or delay 
completion of some or all of the requirements of Section 603 by 
providing a written finding that this final rule is being promulgated 
in response to an emergency that makes compliance or timely compliance 
with the provisions of Section 603 impracticable.
    We are performing a review to determine whether this final rule AD 
action will have a significant economic impact on a substantial number 
of small entities. However, the immediate safety of flight conditions 
of this AD action make compliance with the provisions of Section 603 
impracticable. Our justification for immediate adoption of this rule, 
and therefore of impracticability, is stated in FAA's Justification and 
Determination of the Effective Date. After we determine whether this 
final rule AD action has a significant economic impact on a substantial 
number of small entities or not, we will publish in the Federal 
Register our determination and, if required, our final regulatory 
flexibility analysis.

Examining the AD Docket

    You may examine the AD docket that contains the 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.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

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) 
2010-13-08, Amendment 39-16339 (75 FR 35616, June 23, 2010), and by 
adding a new AD to read as follows:

2010-17-18 Air Tractor, Inc.: Amendment 39-16412; Docket No. FAA-
2010-0827; Directorate Identifier 2010-CE-029-AD.

Effective Date

    (a) This AD becomes effective on September 9, 2010.

Affected ADs

    (b) This AD supersedes AD 2010-13-08; Amendment 39-16339.

Applicability

    (c) This AD affects Models AT-802 and AT-802A airplanes, all 
serial numbers (SNs) beginning with -0001, 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) Air Transport Association of America (ATA) Code 57: Wings.

Unsafe Condition

    (e) This AD results from our determination that we need to 
require the actions in the new service information to add 
inspections, add modifications, and change the safe life for certain 
SN ranges. 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) 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 cracks   Initially inspect upon accumulating   Follow Snow Engineering Co. Process
 the center splice joint outboard      1,700 hours time-in-service (TIS)     Specification 197, page 1,
 two fastener holes in both the left   or within the next 50 hours TIS       revised June 4, 2002; pages 2
 and right wing main spar lower        after April 21, 2006 (the effective   through 4, dated February 23, 2001;
 caps.                                 date of AD 2006-08-09), whichever     and page 5, dated May 3, 2002.
                                       occurs later, and repetitively
                                       thereafter at intervals not to
                                       exceed 800 hours TIS. If, before
                                       September 9, 2010 (the effective
                                       date of this AD), you installed the
                                       center splice plate and extended 8-
                                       bolt splice blocks, use the
                                       inspection compliance times found
                                       in paragraph (f)(5) of this AD.

[[Page 52258]]

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

[[Page 52259]]

(ii) Eddy current inspect for cracks  (B) Between 3,200 hours TIS and
 the center splice joint outboard      4,100 hours TIS.
 two fastener holes in both the left
 and right wing main spar lower
 caps. This eddy current inspection
 is required as part of the
 modification and is separate from
 the inspections required in
 paragraph (f)(1) of this AD.
----------------------------------------------------------------------------------------------------------------

     (5) If, before September 9, 2010 (the effective date of this 
AD) or as a result of performing the repair for cracks following 
paragraph (f)(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 (f)(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 (f)(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 this AD),
 repetitive inspection         whichever occurs
 requirements of this          later.
 paragraph.
(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 this AD),          TIS until the 8,000
                               whichever occurs      hours TIS spar
                               later.                replacement time.
(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 this AD),
                               whichever occurs
                               later.
------------------------------------------------------------------------

     (g) 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 cracks   Initially inspect upon accumulating   Follow Snow Engineering Co. Service
 the center splice joint outboard      1,700 hours TIS or within the next    Letter 284, dated October
 two fastener holes in both the left   50 hours TIS after September 9,       4, 2009; and Snow Engineering Co.
 and right wing main spar lower        2010 (the effective date of this      Process Specification 197,
 caps.                                 AD), whichever occurs later, and      page 1, revised June 4, 2002; pages
                                       repetitively thereafter at            2 through 4, dated February 23,
                                       intervals not to exceed 800 hours     2001; and page 5, dated May 3,
                                       TIS. If the center splice plate, P/   2002.
                                       N 20994-2, is installed as           ....................................
                                       specified in paragraph (g)(4) of
                                       this AD, do the repetitive
                                       inspections at intervals not to
                                       exceed 2,000 hours TIS.
(2) If you find any cracks as a       Before further flight after the       Follow Snow Engineering Co. Service
 result of any inspection required     inspection where a crack was found.   Letter 284, dated October
 by paragraph (g)(1) of this AD, do                                          4, 2009; and Snow Engineering Co.
 the following actions. This repair                                          Process Specification 197,
 modification terminates the                                                 page 1, revised June 4, 2002; pages
 repetitive inspections required in                                          2 through 4, dated February 23,
 paragraph (g)(1) of this AD:                                                2001; and page 5, dated May 3,
(i) For cracks that can be repaired,                                         2002, Snow Engineering Co. Service
 repair the airplane by doing the                                            Letter 281, dated August
 following actions:                                                          1, 2009; and Snow Engineering Co.
(A) Install the 9-bolt splice blocks                                         Drawing Number 20995, Sheet 3,
 and cold-work the lower spar cap                                            dated November 25, 2005.
 fastener holes;

[[Page 52260]]

(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 paragraph
 (g)(1) of this AD; and
(C) Install the center splice plate,
 P/N 20994-2, per paragraph (g)(4)
 if not already installed.
(ii) For cracks that cannot be
 repaired by doing the actions in
 paragraph (g)(2)(i) of this AD,
 replace the lower spar caps and
 associated parts listed following
 the procedures identified in
 paragraph (g)(3) of this AD.
(3) Replace the wing main spar lower   (i) Do the replacement at whichever  Follow Snow Engineering Co. Service
 caps, the web plates, the center      of the following compliance times     Letter 284, dated October
 joint splice blocks and hardware,     occurs first:                         4, 2009; Snow Engineering Co.
 and the wing attach angles and       (A) Before further flight when         Service Letter 80GG,
 hardware, and install the steel web   cracks are found that cannot be       revised December 21, 2005; Snow
 splice plate. This replacement        repaired by incorporating the         Engineering Co. Drawing Number
 terminates the repetitive             modification in paragraph (g)(2)(i)   20975, Sheet 4, Rev. A, dated
 inspections required in paragraph     of this AD; or                        January 7, 2009.
 (g)(1) of this AD.                   (B) Before or when 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 this AD),
                                       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
                                       (g)(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.
(4) To extend the safe life of the    Before the airplane reaches a total   Follow Snow Engineering Co. Service
 wing main spar lower cap to a total   of 4,100 hours TIS. After             Letter 284, dated October
 of 8,000 hours TIS, you may           installation of the center splice     4, 2009; Snow Engineering Co.
 incorporate the following optional    plate, P/N 20994-2, do the            Process Specification 197,
 modification:                         repetitive inspections required in    page 1, revised June 4, 2002; pages
(i) Install center splice plate, P/N   paragraph (g)(1) at intervals not     2 through 4, dated February 23,
 20994-2, if not already installed     to exceed 2,000 hours TIS. If as of   2001; and page 5, dated May 3,
 as part of a repair, and cold-work    September 9, 2010 (the effective      2002; Snow Engineering Co. Drawing
 the lower spar cap fastener holes;    date of this AD) you have already     Number 20975, Sheet 4, Rev. A.,
 and                                   exceeded the 4,100 hours TIS          dated January 7, 2009; and Snow
(ii) Eddy current inspect for cracks   threshold for extending the safe      Engineering Co. Service Letter
 the center splice joint outboard      life to 8,000 hours TIS, you may be   245, dated April 25, 2005.
 two fastener holes in both the left   eligible for an alternative method
 and right wing main spar lower        of compliance following paragraph
 caps. This eddy current inspection    (m) in this AD.
 is required as part of the
 modification and is separate from
 the inspections required in
 paragraph (g)(1) of this AD.
(5) If you find any cracks as a       Before further flight after the       Follow Snow Engineering Co. Service
 result of any repetitive inspection   inspection where a crack was found.   Letter 284, dated October
 required by paragraph (g)(4) of                                             4, 2009; and Snow Engineering Co.
 this AD, do the following actions.                                          Process Specification 197,
 This repair modification terminates                                         page 1, revised June 4, 2002; pages
 the repetitive inspections required                                         2 through 4, dated February 23,
 in paragraph (g)(4) of this AD:                                             2001; and page 5, dated May 3,
(i) For cracks that can be repaired,                                         2002, Snow Engineering Co. Service
 repair the airplane by doing the                                            Letter 281, dated August
 following actions:                                                          1, 2009; and Snow Engineering Co.
(A) Install the 9-bolt splice blocks                                         Drawing Number 20995, Sheet 3,
 and cold-work the lower spar cap                                            dated November 25, 2005.
 fastener holes; and

[[Page 52261]]

(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 paragraph
 (g)(1) of this AD.
(ii) For cracks that cannot be
 repaired by doing the actions in
 paragraph (g)(5)(i) of this AD,
 replace the lower spar caps and
 associated parts listed following
 the procedures identified in
 paragraph (g)(3) of this AD.
----------------------------------------------------------------------------------------------------------------

    (h) 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 current        Before the airplane reaches a total   Follow Snow Engineering Co. Process
 inspection for cracks of the center   of 5,500 hours TIS or within the      Specification 197, page 1,
 splice joint outboard two fastener    next 50 hours TIS after September     revised June 4, 2002; pages 2
 holes in both the left and right      9, 2010 (the effective date of this   through 4, dated February 23, 2001;
 wing main spar lower caps. After      AD), whichever occurs later.          and page 5, dated May 3, 2002; Snow
 this initial inspection, you may do                                         Engineering Co. Service Letter
 the optional cold-working of the                                            245, dated April 25, 2005;
 lower spar cap fastener holes to                                            and Snow Engineering Co. Service
 increase the hours TIS between                                              Letter 284, dated October
 repetitive inspections required in                                          4, 2009.
 paragraph (h)(2) of this AD.
(2) Repetitively eddy current          (i) For fastener holes that are      Follow Snow Engineering Co. Process
 inspect for cracks the center         cold-worked: After the initial        Specification 197, page 1,
 splice joint outboard two fastener    inspection, repetitively thereafter   revised June 4, 2002; pages 2
 holes in both the left and right      inspect at intervals not to exceed    through 4, dated February 23, 2001;
 wing main spar lower caps.            2,200 hours TIS.                      and page 5, dated May 3, 2002; Snow
                                      (ii) For fastener holes not cold-      Engineering Co. Service Letter
                                       worked: After the initial             284, dated October 4,
                                       inspection, repetitively thereafter   2009; and (optional) Snow
                                       inspect at intervals not to exceed    Engineering Co. Service Letter
                                       1,100 hours TIS.                      245, dated April 25, 2005.
(3) If you find any cracks as a       Before further flight after the       Follow Snow Engineering Co. Service
 result of any inspection required     inspection where a crack was found.   Letter 281, dated August
 by paragraphs (h)(1) and (h)(2) of                                          1, 2009; and Snow Engineering Co.
 this AD, do the following actions.                                          Drawing Number 20995, Sheet 3,
 This modification terminates the                                            dated November 25, 2005.
 repetitive inspections required in
 paragraph (h)(1) and (h)(2) of this
 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
 (h)(1) and (h)(2) of this AD.
(ii) For cracks that cannot be
 repaired by doing the actions in
 paragraph (h)(3)(i) of this AD,
 replace the lower spar caps and
 associated parts listed following
 the procedures in paragraph (h)(4)
 of this AD.

[[Page 52262]]

(4) Replace the wing main spar lower  (i) Do the replacement at whichever   Follow Snow Engineering Co. Service
 caps, the web plates, the center      of the following compliance times     Letter 284, dated October
 joint splice blocks and hardware,     occurs first:                         4, 2009; Snow Engineering Co.
 and the wing attach angles and       (A) Before further flight when         Service Letter 80GG,
 hardware, and install the steel web   cracks are found that cannot be       revised December 21, 2005; Snow
 splice plate. This replacement        repaired by incorporating the         Engineering Co. Drawing Number
 terminates the repetitive             repair in paragraph (h)(3)(i) of      20975, Sheet 4, Rev. A, dated
 inspections required in paragraphs    this AD; or                           January 7, 2009.
 (h)(1) and (h)(2) of this AD.        (B) Before or when 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 this AD),
                                       whichever occurs later.
                                         (ii) After this replacement the
                                          new spar safe life is 11,700
                                          hours TIS.
----------------------------------------------------------------------------------------------------------------

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

    (j) To address this problem for AT-802 and AT-802A airplanes, 
SNs -0270 and subsequent, you must do the following, unless already 
done:

                                  Table 6--Actions, Compliance, and Procedures
----------------------------------------------------------------------------------------------------------------
               Actions                             Compliance                            Procedures
----------------------------------------------------------------------------------------------------------------
Replace the wing main spar lower      By the 11,700 hours TIS safe-life or  Follow Snow Engineering Co. Service
 caps, the web plates, the center      within the next 50 hours TIS after    Letter 284, dated October
 joint splice blocks and hardware,     September 9, 2010 (the effective      4, 2009; Snow Engineering Co.
 and the wing attach angles and        date of this AD), whichever occurs    Service Letter 80GG,
 hardware, and install the steel web   later. After this replacement the     revised December 21, 2005; Snow
 splice plate.                         subsequent new spar safe life is      Engineering Co. Drawing Number
                                       11,700 hours TIS.                     20975, Sheet 4, Rev. A, dated
                                                                             January 7, 2009.
----------------------------------------------------------------------------------------------------------------

     (k) Report any crack from any inspection required in paragraphs 
(f), (g), or (h) 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; telephone: (210) 308-3365; facsimile: (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 part 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.

                     AD 2010-17-18 INSPECTION REPORT
                    [REPORT ONLY IF CRACKS ARE FOUND]
------------------------------------------------------------------------

------------------------------------------------------------------------
                           General Information
------------------------------------------------------------------------
1. Inspection Performed By:          2. Phone:
------------------------------------------------------------------------
3. Aircraft Model:                   4. Aircraft Serial Number:
------------------------------------------------------------------------
5. Engine Model Number:              6. Aircraft Total Hours TIS:
------------------------------------------------------------------------

[[Page 52263]]

7. Wing Total Hours TIS:             8. Lower Spar Cap Hours TIS:
------------------------------------------------------------------------
                   Previous Inspection/Repair History
------------------------------------------------------------------------
9. Has the lower spar cap been       If yes, an inspection has occurred:
 inspected (eddy[dash]current, dye   Date:------------------------
 penetrant, magnetic particle, or    Inspection Method:------------
 ultrasound) before?                 Lower Spar Cap TIS:------------
[squ] Yes [squ] No                   Cracks found? [squ] Yes [squ] No
------------------------------------------------------------------------
10. Has there been any major repair  If yes, specify (Description and
 or alteration performed to the       hours TIS):
 spar cap?
[squ] Yes [squ] No
------------------------------------------------------------------------
                      Inspection for AD 2010-17-18
------------------------------------------------------------------------
11. Date of AD inspection:           11a. Cracks found:
    Inspection Results:              [squ] Left Hand [squ] Right Hand
------------------------------------------------------------------------
11b. Crack Length:------------       11c. Does drilling hole to next
                                      larger size remove all traces of
                                      the crack(s)?
    Location:------------            [squ] Yes [squ] No
------------------------------------------------------------------------
12d. Corrective Action Taken:
------------------------------------------------------------------------
Mail report (only if you find any cracks as a result of the inspection
  for AD 2010-17-18) to: 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.
Figure 1

Alternative Methods of Compliance (AMOCs)

    (m) 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, 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.
    (n) AMOCs approved for AD 2010-13-08 are not approved for this 
AD.

Material Incorporated by Reference

    (o) You must use Snow Engineering Co. Service Letter 
80GG, revised December 21, 2005; Snow Engineering Co. 
Service Letter 284, dated October 4, 2009; Snow Engineering 
Co. Service Letter 281, dated August 1, 2009; Snow 
Engineering Co. Service Letter 245, dated April 25, 2005; 
Snow Engineering Co. Service Letter 240, dated September 
30, 2004; Snow Engineering Co. Process Specification 197, 
page 1, revised June 4, 2002; pages 2 through 4, dated February 23, 
2001; and page 5, dated May 3, 2002; Snow Engineering Co. Drawing 
Number 20995, Sheet 3, dated November 25, 2005; Snow Engineering Co. 
Drawing Number 20995, Sheet 2, Rev. D., dated November 25, 2005; and 
Snow Engineering Co. Drawing Number 20975, Sheet 4, Rev. A., dated 
January 7, 2009, to do the actions required by this AD, unless the 
AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of Snow Engineering Co. Service Letter 
80GG, revised December 21, 2005; Snow Engineering Co. 
Service Letter 284, dated October 4, 2009; Snow Engineering 
Co. Service Letter 281, dated August 1, 2009; Snow 
Engineering Co. Service Letter 245, dated April 25, 2005; 
Snow Engineering Co. Drawing Number 20995, Sheet 3, dated November 
25, 2005; Snow Engineering Co. Drawing Number 20995, Sheet 2, Rev. 
D., dated November 25, 2005; and Snow Engineering Co. Drawing Number 
20975, Sheet 4, Rev. A., dated January 7, 2009, under 5 U.S.C. 
552(a) and 1 CFR part 51.
    (2) On April 21, 2006 (71 FR 19994, April 19, 2006), the 
Director of the Federal Register approved the incorporation by 
reference of Snow Engineering Co. Service Letter 240, dated 
September 30, 2004; and Snow Engineering Co. Process Specification 
197, page 1, revised June 4, 2002; pages 2 through 4, dated 
February 23, 2001; and page 5, dated May 3, 2002.
    (3) 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.
    (4) You may review copies of the service information 
incorporated by reference for this AD at the FAA, Central Region, 
Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 
64106. For information on the availability of this material at the 
Central Region, call (816) 329-3768.
    (5) You may also review copies of the service information 
incorporated by reference for this AD at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call (202) 741-6030, or go to: http://
www.archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.

    Issued in Kansas City, Missouri on August 11, 2010.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-20555 Filed 8-24-10; 8:45 am]
BILLING CODE 4910-13-P