[Federal Register Volume 71, Number 153 (Wednesday, August 9, 2006)]
[Proposed Rules]
[Pages 45467-45471]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-12949]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-20007; Directorate Identifier 2004-CE-50-AD]
RIN 2120-AA64


Airworthiness Directives; Air Tractor, Inc. Model AT-602 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
the comment period.

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SUMMARY: The FAA proposes to revise an earlier proposed airworthiness 
directive (AD) that applies to all Air Tractor, Inc. (Air Tractor) 
Model AT-602 airplanes. The earlier NPRM would have required you to 
repetitively inspect (using the eddy current method) the wing center 
splice joint two outboard fastener holes on both of the wing main spar 
lower caps for fatigue cracking; repair or replace any wing main spar 
lower cap where fatigue cracking is found; and report any fatigue 
cracking found. The NPRM resulted from fatigue cracking at the wing 
center splice joint outboard fastener hole in one of the wing main spar 
lower caps. Since issuing the NPRM, the FAA has received and evaluated 
new information that decreases the compliance time to initially inspect 
certain serial numbers. This proposed AD includes the new compliance 
times in the table located in paragraph (e)(2) of this AD. Since these 
actions impose an additional burden over that proposed in the earlier 
NPRM, we are reopening the comment period to allow the public the 
chance to comment on these additional actions.

DATES: We must receive any comments on this proposed AD by October 10, 
2006.

ADDRESSES: Use one of the following to submit comments on this proposed 
AD:
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: 1-202-493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    To get service information identified in this AD, contact Air 
Tractor, Inc. at P.O. Box 485, Olney, Texas 76374; telephone: (940) 
564-5616; or facsimile: (940) 564-5612.
    You may examine the comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

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

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include the docket number, ``FAA-2004-20007; 
Directorate Identifier 2004-CE-50-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed rulemaking.

Discussion

    The FAA received a report of fatigue cracking of the wing main spar 
lower cap at the wing center splice joint outboard fastener hole on one 
Air Tractor Model AT-602 airplane. The airplane had 2,895 hours time-
in-service (TIS) at the time the cracking was discovered. The fatigue 
cracking is similar to that found on other Air Tractor airplane model 
wings.
    Cracks in the wing main spar lower cap could result in failure of 
the spar cap and lead to wing separation and loss of control of the 
airplane.
    The following table contains AD actions that address the wing spar 
safe life of the Air Tractor airplane fleet:

                           Related AD Actions
------------------------------------------------------------------------
                                     Affected Air
             AD No.                  Tractor model          Status
                                       airplanes
------------------------------------------------------------------------
2000-14-51......................  AT-501, AT-502,     Superseded by AD
                                   and AT-502A.        2001-10-04.
2001-10-04......................  AT-400, AT-500,     Revised by AD 2001-
                                   and AT-800 Series.  10-04 R1.

[[Page 45468]]

 
2001-10-04 R1...................  AT-400, AT-500,     Superseded by AD
                                   and AT-800 Series.  2002-11-05.
2002-11-05......................  AT-400, AT-401, AT- Revised by AD 2002-
                                   401B, AT-402, AT-   11-05 R1.
                                   402A, AT-402B, AT-
                                   501, AT-802, and
                                   AT-802A.
2002-13-02......................  AT-300, AT-301, AT- Superseded by AD
                                   302, AT-400, and    2003-06-01.
                                   AT-400A Airplanes.
2002-11-03......................  AT-502, AT-502A,    Superseded by AD
                                   AT-502B, and AT-    2002-26-05.
                                   503A.
2002-26-05......................  AT-502, AT-502A,    Current.
                                   AT-502B, and AT-
                                   503A.
2003-06-01......................  AT-300, AT-301, AT- Current.
                                   302, AT-400, and
                                   AT-400A.
2002-11-05 R1...................  AT-501............  Current.
2006-08-08......................  AT-400, AT-401, AT- Current.
                                   401B, AT-402, AT-
                                   402A, and AT-402B.
2006-08-09......................  AT-802 and AT-802A  Current.
------------------------------------------------------------------------

    You may view these ADs at the following Internet Web site 
addresses: http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/MainFrame?OpenFrameSet or http://www.gpoaccess.gov/fr/index.html.
    We issued a proposal to amend part 39 of the Federal Aviation 
Regulations (14 CFR part 39) to include an AD that would apply to all 
Air Tractor Model AT-602 airplanes. This proposal was published in the 
Federal Register as a notice of proposed rulemaking (NPRM) on February 
22, 2005 (70 FR 8549). The NPRM proposed to require you to repetitively 
inspect (using the eddy current method) the wing center splice joint 
two outboard fastener holes on both of the wing main spar lower caps 
for fatigue cracking; repair or replace any wing main spar lower cap 
where fatigue cracking is found; and report any fatigue cracking found.
    The FAA encouraged interested persons to participate in developing 
this amendment. The following presents the comments received on the 
proposal and FAA's response to each comment:

Comment Issue No. 1: Maintenance Required During the Peak Spraying 
Season

    The National Agricultural Aviation Association (NAAA), while 
recognizing immediate concerns to safety occur, requests the FAA 
consider the unique operating season of aerial application businesses 
and attempt to write ADs so compliance can be made during off-season 
maintenance. Deferring maintenance to the off-season minimizes the 
financial impact and loss of airplane availability to operators during 
the peak spraying season. The operators perceive that constant 
revisions of potential solutions to the wing spar cracking problems 
prevent them from prorating their potential expenses or planning the 
timing of required maintenance.
    The FAA agrees with the NAAA. We should consider the importance of 
the financial and operational impact any rulemaking will have on owners 
and operators and, in this specific case, aerial application 
businesses. This proposed rule uses inspections to manage the safety of 
the wing centerline joint instead of reducing the compliance times for 
replacing parts. However, this approach can not be used indefinitely. 
Extending the service life of fatigue-critical, primary structure areas 
requires not only ensuring the safety of the area being inspected or 
modified, but also ensuring the safety of the complete structure when 
extending the service life.
    We are not changing the proposed AD based on this comment.

Comment Issue No. 2: Incorrect Costs of Inspection and Modification

    Leland Snow, President of Air Tractor, and Lewis Broussard, owner 
of Lewis's Flying Service, state that the costs associated with the 
inspection and modification in the NPRM are not correct.
    The FAA partially agrees. We have revised the costs for the 
inspection and repairs or terminating actions. The proposed rulemaking 
does not reduce the current safe-life of the lower spar caps. Since the 
replacement time is not changed from the current safe-life approved at 
certification, the replacement costs are not applicable to this NPRM.

Comment Issue No. 3: Reference to Aluminum Spar Caps Should be Steel 
Spar Caps

    Leland Snow, President of Air Tractor, states that there are 
references made to aluminum spar caps, and the Air Tractor Model AT-602 
only uses steel spar caps. Also change ``lower wing spars caps'' to 
``lower wing spar caps.'' The commenter believes this is a 
typographical error.
    The FAA agrees. All references to aluminum spar caps have been 
removed. The typographical error has also been corrected.

Comment Issue No. 4: Incorrect Telephone Numbers

    Leland Snow, President of Air Tractor, requests we change the 
contact telephone numbers for Air Tractor, Inc. They are incorrect.
    The FAA agrees. Contact Air Tractor at telephone number (940) 564-
5616 and facsimile number (940) 564-5612. The supplemental NPRM 
reflects this change.

Comment Issue No. 5: Snow Engineering Co. Process Specification 
205

    Leland Snow, President of Air Tractor, recommends deleting the 
reference to Snow Engineering Co. Process Specification 205, 
dated April 26, 2004, and using serial numbers (S/Ns) 602-0695 and 
subsequent to identify the factory cold-worked spar caps. Process 
Specification 205 contains the procedures for cold-working 
production airplanes and requires a CNC Mill. Airplanes starting with 
S/N 602-0695 are cold-worked in production using Process Specification 
205.
    The FAA partially agrees. Snow Engineering Co. Drawing 20776, sheet 
2, Revision A, dated August 30, 2004, Note 19 refers to Process 
Specification 205 to cold work and line-ream the lower spar 
caps and attach blocks. The drawing applies to S/N 602-0695 and 
subsequent S/Ns that were cold worked in production, but according to 
Drawing Note 23, airplanes with S/Ns back to 602-0337 can also be 
retrofitted with cold worked parts. Therefore, it is possible that an 
early S/N airplane may

[[Page 45469]]

receive replacement spar caps cold-worked and line-reamed by Process 
Specification 205 according to Drawing 20776. Airplane S/Ns 
before 602-0695 may also receive cold working by Snow Engineering Co. 
Service Letter 244, dated April 25, 2005; or by Service Letter 
240, dated September 30, 2004, if modified by Snow Engineering 
Drawing 20998, Revision B, dated September 28, 2004.
    To simplify, we will revise the proposed AD as follows: For 
inspection, we will refer to airplane S/Ns where possible in the AD, 
refer to the Service Letter 244 for in-service cold working; 
Drawing Number 20998 and Service Letter 240 as terminating 
action for inspection and for repair; and Snow Engineering Co. Drawing 
20776 for spar cap replacement.

Comment Issue No. 6: Unclear Drill Size and Intent of Repair

    For paragraph (f)(1) of the previous proposed AD, Leland Snow, 
President of Air Tractor, believes the next larger drill size is 
unclear and the intent of the repair is unclear.
    The FAA agrees. We have revised the wording to clarify the intent 
of the repair of cracks.

Comment Issue No. 7: Dates of Service Information

    Leland Snow, President of Air Tractor, wants the AD to call out the 
date on all drawings and service letters and add the text ``or later 
FAA-approved revision.''
    The FAA partially agrees. The AD will include dates with the 
reference materials. The FAA can not include the text ``or later FAA-
approved revision'' since we can not approve data that does not already 
exist.
    Air Tractor may work with the FAA to include a statement in future 
revisions that considers that service information as an alternative 
method of compliance.

Comment Issue No. 8: Modifying the wing versus replacing the lower spar 
caps

    Leland Snow, President of Air Tractor, Inc., asks that we add 
installation of a steel plate at the wing splice joint, drilling the 
lower spar caps and installing extended splice blocks, and cold working 
critical fastener holes in lieu of lower spar cap replacement as a 
method to extend operating the wing past the current safe-life. The 
cost of modifying the wing is cheaper than replacing the lower spar 
caps and associated components and hardware. The manufacturer's 
resources to supply parts and change spar caps are limited, and the 
timeliness of spar cap replacement during the spray season when 
airplanes are operating makes doing this even more difficult.
    The FAA disagrees. Extending the safe-life of primary structure 
requires not only substantiating the safety of the area being inspected 
or modified, but also ensuring the complete structure remains safe when 
extending the life. A full-scale fatigue test of the airplane's 
structure is the preferred method of extending the original safe-life, 
especially when the original design was substantiated by analysis, as 
in the case of the Model AT-602 airplane wing.
    Based on the data that is currently available, the FAA is unable to 
extend the safe-life.
    We are not changing the proposed AD based on this comment.

Comment Issue No. 9: Compliance Times

    The National Transportation Safety Board (NTSB) requests we lower 
the initial inspection time for unmodified wing spars from 2,500 hours 
TIS to 2,000 hours TIS; and lower the recurring inspection intervals to 
a time unspecified by the commenter.
    The FAA partially agrees. The manufacturer has provided new data 
since we published the original NPRM that confirms a fatigue life of 
2,000 hours TIS for Model AT-602 airplanes, S/N 602-0337 through S/N 
602-0584. This fatigue life is based on a recent FAA-approved usage 
spectrum and applies to airplanes not having a steel spar web plate 
installed. The same data show all other Model AT-602 airplanes are 
exempt from inspection. The FAA also did a Weibull analysis for the 
Model AT-602 fleet based on known service history that supports the 
2,000-hour TIS fatigue life. We will establish the initial inspection 
time at 2,000 hours TIS for airplanes without the steel web plate based 
on this new information.
    The recurring inspection intervals specified in the NPRM are based 
on FAA-approved damage tolerance testing and analysis. The specified 
intervals allow for performing at least two inspections before a 
detectable crack would grow to critical length. For further 
conservatism, the crack growth testing and analysis and resultant 
intervals are based on a usage spectrum that the FAA believes 
represents usage more severe than would be expected in routine service.

Relevant Service Information

    We have reviewed the following Snow Engineering Co. service 
information:
     Process Specification 197, revised June 4, 2002, 
Drawing 20776, Sheet 2, Revision A, dated August 30, 2004;
     Service Letter 204, revised March 26, 2001;
     Service Letter 240, dated September 30, 2004;
     Drawing 20998, Revision B, dated September 28, 2004; and
     Service Letter 244, dated April 25, 2005.
    The service information includes procedures for:
     Preparing the airplane and the eddy current machine for 
inspection of the lower wing spar caps;
     Inspecting the lower wing spar caps for cracks;
     Verifying suspected cracks for steel lower wing spar caps;
     Repairing the cracks by installing a web plate and 8-bolt 
splice block; and
     Replacing the spar caps and associated hardware.
    Snow Engineering Co. has a licensing agreement with Air Tractor 
that allows them to produce technical data for use on Air Tractor 
products.

FAA's Determination and Requirements of This Proposed AD

    Since issuing the earlier NPRM, the FAA has received and evaluated 
new information that decreases the compliance time to initially inspect 
on certain S/Ns. This proposed AD includes the new compliance times in 
the table located in paragraph (e)(2) of this proposed AD.
    After examining the circumstances and reviewing all available 
information related to the incidents described above, we have 
determined that:
     The unsafe condition referenced in this document exists or 
could develop on other Air Tractor Model AT-602 airplanes of the same 
type design that are on the U.S. registry;
     We should change the NPRM to eliminate the inspection 
requirements for all S/Ns beginning with 602-0585, to shorten the 
compliance times for the initial inspection on S/Ns 602-0337 through S/
N 602-0584, and to provide terminating action for repetitive 
inspections on S/Ns 602-0337 through S/N 602-0584; and
     We should take AD action to correct this unsafe condition.

The Supplemental NPRM

    Proposing a shorter compliance time for the initial inspection for 
certain airplanes goes beyond the scope of what was originally proposed 
in the NPRM. Therefore, we are reopening the comment period and 
allowing the public the chance to comment on these additional actions.

[[Page 45470]]

    The proposed AD would require you to repetitively inspect (using 
the eddy current method) the wing center splice joint two outboard 
fastener holes in the wing main spar lower caps for cracks and repair 
or replace any cracked spar cap.

Costs of Compliance

    We estimate that this proposed AD affects 107 airplanes in the U.S. 
registry.
    We estimate the following costs to do this proposed inspection:

----------------------------------------------------------------------------------------------------------------
                                                                   Eddy current   Total cost per   Total cost on
                   Labor cost                       Parts cost      inspection       airplane     U.S. operators
----------------------------------------------------------------------------------------------------------------
Initial inspection and installation of access               $645           *$500          $3,065        $327,955
 panels -24 work-hours x $80 = $1,920...........
Repetitive Inspection (each)....................             $60           *$800            $860         $92,020
----------------------------------------------------------------------------------------------------------------
* Eddy current inspections are an estimated flat cost that includes labor and use of equipment.

    We estimate the following costs to do any necessary repairs that 
would be required based on the results of the proposed inspection. We 
have no way of determining the number of airplanes that may need this 
repair:

------------------------------------------------------------------------
                                                          Total cost per
               Labor cost                   Parts cost       airplane
------------------------------------------------------------------------
Install web plate, 8-bolt splice blocks,          $6,900         $18,980
 and cold work fastener holes: Air
 Tractor estimated a labor cost of
 $12,100. When broken down into work-
 hours, we estimated 151 work-hours to
 complete the task. 151 work-hours x $80
 = $12,080..............................
Cold work fastener holes following Snow           $1,350          $2,870
 Engineering Co. Service Letter 244, dated April 25, 2005: 19 work-
 hours x $80 = $1,520...................
------------------------------------------------------------------------

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 airplanes 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 AD.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this proposed AD:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979); and
    3. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a summary of the costs to comply with this proposed AD 
(and other information as included in the Regulatory Evaluation) and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket FAA-2004-20007; Directorate Identifier 2004-CE-50-AD'' in 
your request.

Examining the Dockets

    You may examine the docket that contains the proposal, any comments 
received, and any final disposition on the Internet at http://dms.dot.gov, or in person at the DOT Docket Offices between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The Docket 
Office (telephone 1-800-647-5227) is located on the plaza level of the 
Department of Transportation NASSIF Building at the street address 
stated in ADDRESSES. Comments will be available in the AD docket 
shortly after the Docket Management Facility receives them.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 14 
CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Air Tractor, Inc.: Docket No. FAA-2004-20007; Directorate Identifier 
2004-CE-50-AD.

Comments Due Date

    (a) We must receive comments on this proposed airworthiness 
directive (AD) by October 10, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD affects Model AT-602 airplanes, all serial numbers 
beginning with 602-0337, that are certificated in any category.

Unsafe Condition

    (d) This AD is the result of fatigue cracking of the wing main 
spar lower cap at the centerline splice joint outboard fastener 
hole. The actions specified in this AD are intended to detect and 
correct cracks in the wing main spar lower cap, which could result 
in failure

[[Page 45471]]

of the spar cap and lead to wing separation and loss of control of 
the airplane.

Compliance

    (e) To address the problem, do the following:
    (1) Before doing the initial eddy current inspection required in 
paragraph (e)(2) of this AD, gain access for the inspection by 
cutting inspection holes, modifying the vent tube, and installing 
cover plates; unless already done. Follow Snow Engineering Co. 
Service Letter 204, dated October 25, 2000, Drawing titled 
``602 Spar Inspection Holes and Vent Tube Mod.,'' dated November 13, 
2003.
    (2) Eddy current inspect the wing center splice joint outboard 
two fastener holes in both the right and left wing main spar lower 
caps for cracks. Follow Snow Engineering Co. Process Specification 
197, Revised June 4, 2002. For the following airplanes, use 
the wing spar lower cap hours time-in-service (TIS) schedule below 
in Table 1.--Compliance Times for Inspection to do the initial and 
repetitive inspections:

                                    Table 1.--Compliance Times for Inspection
----------------------------------------------------------------------------------------------------------------
                                                                                          Repetitively inspect
           Serial Nos.                     Condition              Initially inspect         thereafter at the
                                                                                           following intervals
----------------------------------------------------------------------------------------------------------------
(i) 602-0337 through 602-0584....  As manufactured..........  Upon accumulating 2,000   1,000 hours TIS.
                                                               hours TIS or within 50
                                                               hours TIS after the
                                                               effective date of this
                                                               AD, whichever occurs
                                                               later, unless already
                                                               done.
(ii) 602-0337 through 602-0584...  Modified with cold-worked  If performing the cold-   2,000 hours TIS.
                                    fastener holes following   working procedure in
                                    Snow Engineering Co.       Service Letter 244, it includes the
                                    i>244, dated April 25,     eddy current inspection.
                                    2005.
----------------------------------------------------------------------------------------------------------------

    (3) Do an eddy current inspection as part of the cold working 
procedure in Service Letter 244, dated April 25, 2005, even 
if the wing spar was previously inspected.
    (4) One of the following must do the inspection:
    (i) A level 2 or 3 inspector certified in eddy current 
inspection using the guidelines established by the American Society 
for Nondestructive Testing or NAS 410; or
    (ii) A person authorized to perform AD maintenance work and who 
has completed and passed the Air Tractor, Inc. training course on 
Eddy Current Inspection on wing lower spar caps.
    (f) For the airplanes listed in paragraph (e)(2) of this AD, as 
terminating action for the inspection requirements, you may modify 
your wing by installing part number (P/N) 20996-2 steel web plate 
and P/N 20985-1/2 8-bolt splice blocks following Snow Engineering 
Co. Drawing 20998, Revision B, dated September 28, 2004, and cold 
work the lower spar cap two outboard fastener holes at the wing 
center section splice connection following Snow Engineering Co. 
Service Letter 240, dated September 30, 2004.
    (g) For all affected airplanes listed in paragraph (e)(2) of 
this AD, repair or replace any cracked spar cap before further 
flight. For repair or replacement, do one of the following:
    (1) For cracks that can be removed by performing the terminating 
action listed in paragraph (f) of this AD above, perform the actions 
in paragraph (f) of this AD.
    (2) For cracks that can not be removed by performing the 
terminating action in paragraph (f) of this AD, you must replace the 
lower spar caps and associated parts listed in paragraph (h) of this 
AD before continued flight.
    (h) For all Model AT-602 airplanes, upon accumulating 6,500 
hours TIS on the wing spar lower caps or within the next 50 hours 
TIS after the effective date of this AD, whichever occurs later, 
replace the wing lower spar caps, splice blocks and hardware, wing 
attach angles and hardware, and install the steel web plate, P/N 
20996-2, if not already installed, following Snow Engineering Co. 
Drawing 20776, Sheet 2, Revision A, dated August 30, 2004. 
Compliance with this paragraph terminates the inspection 
requirements of paragraph (e)(2) of this AD.
    (i) Report any cracks you find within 10 days after the cracks 
are found or within 10 days after the effective date of this AD, 
whichever occurs later. Include in your report the airplane serial 
number, airplane TIS, wing spar cap TIS, crack location and size, 
corrective action taken, and a point of contact name and phone 
number. 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. 
The Office of Management and Budget (OMB) approved the information 
collection requirements contained in this regulation under the 
provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 
and those following sections) and assigned OMB Control Number 2120-
0056.

Alternative Methods of Compliance (AMOCs)

    (j) The Manager, Fort Worth Airplane Certification Office, FAA, 
ATTN: Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 
10100 Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: 
(210) 308-3365; facsimile: (210) 308-3370, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19.

Related Information

    (k) To get copies of the documents referenced in this AD contact 
Air Tractor, Inc. at address P.O. Box 485, Olney, Texas 76374; 
telephone: (940) 564-5616; or facsimile: (940) 564-5612. To view the 
AD docket, go to the Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-
401, Washington, DC, or on the Internet at http://dms.dot.gov. The 
docket number is FAA-2004-20007.

    Issued in Kansas City, Missouri, on August 3, 2006.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-12949 Filed 8-8-06; 8:45 am]
BILLING CODE 4910-13-P