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Published 2006-04-19 · Federal Register document 06-3613

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

Publication summary

The FAA is adopting a new airworthiness directive (AD) for all Air Tractor, Inc. (Air Tractor) Models AT-802 and AT-802A airplanes. 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. This AD results from in-service fatigue cracking of the wing main spar lower cap at the center splice joint outboard fastener hole at hours time-in-service below the safe life limit established for these airplanes in AD 2002-11-05. 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.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:23:20.745856+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_2006-8d787f8b35bc8016
Source row
results[128]
Raw source SHA-256
8d787f8b35bc80165a417cea66de09cd32a1700face13759db364c607e405963

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
2006-08-09
Effective date printed in this edition
2006-04-21
Read 9 complete recorded clauses
When Does This AD Become Effective?
When Does This AD Become Effective?

    (a) This AD becomes effective on April 21, 2006.

Exact source excerpt. Text positions 16982–17073, end exclusive, in the original decoded publication. SHA-256: 0fe7c7674cdbd1c027dc7c82bc1aac0b1de67dda351cdd92a7f22147b5ca8ec5

What Other ADs Are Affected by This Action?
What Other ADs Are Affected by This Action?

    (b) As of the issuance of this action, AD 2002-11-05 applies to 
Models AT-400, AT-401, AT-401B, AT-402, AT-402A, AT-402B, AT-501, 
AT-802, and AT-802A airplanes. The FAA is revising AD 2002-11-05 to 
remove the AT-400 series and AT-800 series airplanes from the 
applicability. The FAA is also issuing another similar AD on the AT-
400 series airplanes.

Exact source excerpt. Text positions 17073–17478, end exclusive, in the original decoded publication. SHA-256: 1ce59b01211c74beabff0bc153fedb9b3b7c57da040dcac5915c34e2998bf387

Applicability wording · What Airplanes Are Affected by This AD?
What Airplanes Are Affected by This AD?

    (c) This AD affects Model AT-802A airplanes, all serial numbers 
beginning with 802-0001, that are:
    (1) Certificated in any category;
    (2) Engaged in agricultural dispersal operations including those 
airplanes that have been converted between fire fighting and 
agricultural dispersal;
    (3) Not equipped with the factory-supplied computerized fire 
gate (part number 80540); and
    (4) Not engaged in full-time fighting only.

Exact source excerpt. Text positions 17478–17962, end exclusive, in the original decoded publication. SHA-256: 6073d1f462032ad0df9420a62e058aa9d7d99492568b6145153977d80c7b5f02

What Is the Unsafe Condition Presented in This AD?
What Is the Unsafe Condition Presented in This AD?

    (d) This AD is the result of fatigue cracking of the wing main 
spar lower cap at the center 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 of the spar cap and lead to wing separation and loss of 
control of the airplane.

Exact source excerpt. Text positions 17962–18372, end exclusive, in the original decoded publication. SHA-256: a91f71dc74737aab973d787752beee2a54bee4a722694d15bb07c8baf63ba205

What Service Information Must I Use To Do the Actions Required by This AD?
What Service Information Must I Use To Do the Actions Required by This 
AD?

    (e) You must use the following Snow Engineering Co. service 
information to do the actions required by this AD:

[[Page 19997]]

    (1) Process Specification <greek-i>197, page 1, revised June 4, 
2002; pages 2 through 4, dated February 23, 2001; and page 5, dated 
May 3, 2002;
    (2) Process Specification <greek-i>204, Rev. C, dated November 
16, 2004;
    (3) Service Letter <greek-i>215, page 5, titled ``802 Spar 
Inspection Holes and Vent Tube Mod,'' dated Novembe 19, 2003;
    (4) Service Letter <greek-i>420, dated September 30, 2004;
    (5) Service Letter <greek-i>244, dated April 25, 2005;
    (6) Drawing Number 20975, Sheet 2, Rev. A, dated September 1, 
2004;
    (7) Drawing Number 20975, Sheet 3, dated January 6, 2005; and
    (8) Drawing Number 20995, Sheet 2, Rev. C., dated September 28, 
2005.

Exact source excerpt. Text positions 18372–19274, end exclusive, in the original decoded publication. SHA-256: 319475b7983598ccbffd5f7c2d86ff6228fa514250b9d10a98cc3c43b7fb6ddb

What Must I Do To Address This Problem?
What Must I Do To Address This Problem?

    (f) At the initial inspection time specified in paragraph (f)(2) 
of this AD, do the following:
    (1) For the affected airplanes listed in Table 1 in paragraph 
(f)(2) of this AD, gain access for the required inspection listed 
below by installing cover plates following Service Letter 
<greek-i>215, page 5, titled ``802 Spar Inspection Holes and Vent 
tube mod,'' dated November 19, 2003.
    (2) For the following airplanes, eddy current inspect the center 
splice joint outboard two fastener holes in both the right and left 
wing main spar lower caps for cracks following Process Specification 
<greek-i>197. For these airplanes, use the following wing spar lower 
cap hours time-in-service (TIS) schedule to do the initial and 
repetitive inspections:

                                           Table 1.--Inspection Times
----------------------------------------------------------------------------------------------------------------
                                                                                           Repetitively inspect
              Serial No.                      Condition            Initially inspect:    thereafter at intervals
                                                                                              not to exceed:
----------------------------------------------------------------------------------------------------------------
(i) 802-0001 through 802-0091........  As manufactured........  Upon accumulating 1,700  850 hours TIS.
                                                                 hours TIS or within 50
                                                                 hours TIS after April
                                                                 21, 2006 (the
                                                                 effective date of this
                                                                 AD), whichever occurs
                                                                 later.
(ii) 802-0001 through 802-0091.......  Modified with cold-      If performing the cold-  1,700 hours TIS.
                                        worked fastener holes    working procedure in
                                        following Service        Service Letter <greek-
                                        Letter <greek-i>244.     i>244, it includes the
                                                                 eddy current
                                                                 inspection.
----------------------------------------------------------------------------------------------------------------

    (3) 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 MIL-STD-410; or
    (ii) A person authorized to perform AD work and who has 
completed and passed the Air Tractor, Inc. training course on Eddy 
Current Inspection on wing lower spar caps.
    (g) For all affected airplanes listed in paragraphs (f)(2)(i) 
and (f)(2)(ii) of this AD as terminating action for the inspection 
requirements, you may modify your wing by installing part number (P/
N) 20997-2 web plate and P/N 20985-1 and 20985-2 extended 8-bolt 
splice blocks following Drawing 20995, Sheet 2, and cold-working the 
outboard two fastener holes in both the left and right hand lower 
spar caps at the center splice joint following Service Letter 
<greek-i>240.
    (h) For all affected airplanes listed in paragraphs (f)(2)(i) 
and (f)(2)(ii) of this AD, repair or replace any cracked spar cap 
before further flight after the inspection in which cracks are 
found. For repair or replacement, do whichever of the following that 
applies:
    (1) For cracks that can be repaired by incorporating the 
terminating action specified in paragraph (g) of this AD, do the 
actions in paragraphs (g) of this AD before further flight after the 
inspection in which cracks are found.
    (2) For cracks that cannot be repaired by incorporating the 
terminating action specified in paragraph (g) of this AD, replace 
the lower spar caps and associated parts listed in paragraph (i) of 
this AD before further flight after the inspection in which cracks 
are found.
    (i) For all AT-802 and AT-802A airplanes, upon accumulating the 
hours TIS on the wing spar lower caps listed in paragraph (i)(3) of 
this AD or within 50 hours TIS after April 21, 2006 (the effective 
date of this AD), whichever occurs later, replace the wing main spar 
lower spar caps, the center joint splice blocks and hardware, the 
wing attach angles and hardware, and install the steel web splice 
plate (P/N 21106-1 for serial numbers 0001 through -0091, and P/N 
20094-2 for all serial numbers beginning with 0092), unless already 
done. Replace as follows:
    (1) For airplane serial numbers 802-0001 through 802-0091, 
follow Drawing Number 20975, Sheet 3, and Process Specification 
<greek-i>204.
    (2) For airplane serial numbers beginning with 802-0092, follow 
Drawing Number 20975, Sheet 2, and Process Specification 
<greek-i>204.
    (3) The following presents the safe life and replacements times 
as required in paragraph (i) of this AD:

                Table 2.--Safe Life and Replacement Times
------------------------------------------------------------------------
                                                    Wing spar lower cap
                   Serial No.                            safe-life
------------------------------------------------------------------------
AT-802-0001 through AT-802-0059.................  4,132 hours TIS.
AT-802-0060 through AT-802-0091.................  4,188 hours TIS.
All begining with AT-802-0092...................  8,163 hours TIS.
AT-802A-001 through AT-802A-0059................  4,969 hours TIS.
AT-802A-0060 through AT-802-0091................  4,531 hours TIS.
All beginning with AT-802A-0092.................  8,648 hours TIS.
------------------------------------------------------------------------

    (j) After replacing the wing spar lower caps and hardware, 
installing the web splice plate, and cold working the fastener holes 
by following Drawing Number 20975, Sheet 3 (serial numbers 802-0001 
through 802-0091), or Sheet 2 (all serial numbers beginning with 
802-0092), and Process Specification <greek-i>204, the new safe-life 
for wing spar lower caps is as follows:

[[Page 19998]]



            Table 3.--New Safe Life for Wing Spar Lower Caps
------------------------------------------------------------------------
                                                    Wing spar lower cap
                   Serial No.                            safe-life
------------------------------------------------------------------------
All beginning with AT-802-0001..................  8,163 hours TIS.
All beginning with AT-802A-0001.................  8,648 hours TIS.
------------------------------------------------------------------------

    (k) Report any cracks you find within 10 days after the cracks 
are found or within 10 days after April 21, 2006 (the effective date 
of this AD), whichever occurs later.
    (1) Include in your report the aircraft serial number, aircraft 
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; fascimile: (210) 308-3370.
    (2) The Office of Management and Budget (OMB) approved the 
information collection requirements contained in ths regulation 
under the provisions of the Paperwork Reduction Act and assigned OMB 
Control Number 2120-0056.

Exact source excerpt. Text positions 19274–27153, end exclusive, in the original decoded publication. SHA-256: 3ccd5b0b71d5497ca05ae2747f5a30933a939e4534104e99856cf561ff3e60f6

May I Request an Alternative Method of Compliance?
May I Request an Alternative Method of Compliance?

    (l) The Manager, Fort Worth Airplane Certification Office, FAA, 
has the authority to aprove alternative methods of compliance for 
this AD, if requested using the procedures found in 14 CFR 39.19. 
For information on any already approved alternative methods of 
compliance or for information pertaining to this AD, contact Andrew 
McAnual, 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.
    (m) AMOCs approved for AD 2001-10-04, AD 2001-10-04 R1, or AD 
2002-11-05 for the Models AT-802 and AT-802A airplanes are not 
considered approved for this AD.

Exact source excerpt. Text positions 27153–27872, end exclusive, in the original decoded publication. SHA-256: 6ef93605aaf2ab85c286dfd1cb41fc8589864a878f461932272139220096a6b1

Special Flight Permit
Special Flight Permit

    (n) 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.

Exact source excerpt. Text positions 27872–28351, end exclusive, in the original decoded publication. SHA-256: 133ca77d2b5b85fb7866f7246ee62bdc0e1c98d43c9ab9f25d1716e03e375880

Does This AD Incorporate Any Material by References?
Does This AD Incorporate Any Material by References?

    (o) You must do the actions required by this AD following the 
instructions in Snow Engineering Co. Process Specification 
<greek-i>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. Process Specification <greek-i>204, Rev. C, dated November 16, 
2004; Snow Engineering Co. Service Letter <greek-i>215, page 5, 
titled ``802 Spar Inspection Holes and Vent Tube Mod,'' dated 
November 19, 2003; Snow Engineering Co. Service <greek-i>240, dated 
September 30, 2004; Snow Engineering Co. Service Letter 
<greek-i>244, dated April 25, 2005; Snow Engineering Co. Drawing 
Number 20975, Sheet 2, Rev. A, dated September 1, 2004; Snow 
Engineering Co. Drawing Number 20975, Sheet 3, dated January 6, 
2005; and Snow Engineering Co. Drawing Number 20995, Sheet 2, Rev. 
C., dated September 28, 2004. The Director of the Federal Register 
approved the incorporation by reference of this service information 
in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To get a copy 
of this service information, contact Air Tractor, Incorporated, P.O. 
Box 485, Olney, Texas 76374. To review copies of this service 
information, go to the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html or call (202) 741-6030. To 
view the AD docket, go to the Docket Management Facility; US 
Department of Transportation, 400 Seventh Street, SW., Nassif 
Building, Room PL-401, Washington, DC 20590-0001 or on the Internet 
at http://dms.dot.gov. The docket number FAA-2005-20591; Directorate 
Identifier 2005-20591; Directorate Identifier 2005-CE-14-AD.

Exact source excerpt. Text positions 28351–30180, end exclusive, in the original decoded publication. SHA-256: a8cb345e01115465d8d1d904e091e0746c2265d09a529a5ca7ab93413e6d9780

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 2006-08-09 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.2.0. Text SHA-256: 7dd4bfff9a84a5de466c39c6566ed47a398688fab75a4c0f8834908ec3ce4dd7. Source manifest: f91eb9181b8c93d8839993bca9eb957c8e20f47af5cc85e8623206673877a93d.

Official source · 2006-04-19

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Literal source encoding markers are preserved as printed strings. They have not been interpreted as symbols or legal requirements.

Read the complete official publication text
[Federal Register Volume 71, Number 75 (Wednesday, April 19, 2006)]
[Rules and Regulations]
[Pages 19994-19998]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-3613]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20591; Directorate Identifier 2005-CE-14-AD; 
Amendment 39-14565; AD 2006-08-09]
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: The FAA is adopting a new airworthiness directive (AD) for all 
Air Tractor, Inc. (Air Tractor) Models AT-802 and AT-802A airplanes. 
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. This AD results from in-service fatigue cracking 
of the wing main spar lower cap at the center splice joint outboard 
fastener hole at hours time-in-service below the safe life limit 
established for these airplanes in AD 2002-11-05. 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 April 21, 2006.
    As of April 21, 2006, the Director of the Federal Register approved 
the incorporation by reference of certain publications listed in the 
regulation.
    We must receive any comments on this AD by June 2, 2006.

ADDRESSES: Use one of the following to submit comments on this AD:
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
    <bullet> Fax: 1-202-493-2251.
    <bullet> 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 the service information identified in this AD, contact Air 
Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564-
5616; facsimile: (940) 564-5612.
    To view the comments to this AD, go to http://dms.dot.gov. The 
docket number is FAA-2005-20591; Directorate Identifier 2005-CE-14 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:

What is the background of the subject matter?

    There have been five previous airworthiness directives (ADs) issued 
related to the wing spar inspection and safe life on Air Tractor 
airplanes:
    <bullet> AD2000-14-51, Amendment 39-11837 (65 FR 46567, July 31, 
2000).
    <bullet> AD2001-10-04, Amendment 39-12230 (66 FR 27014, May 16, 
2001).
    <bullet> AD2001-10-04 R1, Amendment 39-12247 (66 FR 2990, June 4, 
2001).
    <bullet> AD2002-11-05, Amendment 39-12766 (67 FR 37967, May 31, 
2002).
    <bullet> AD2002-26-05, Amendment 39-12991 (68 FR 18, January 2, 
2003).
    AD 2000-14-51: An Air Tractor Model AT-502A experienced an in-
flight wing separation. As a result, the FAA issued AD 2000-14-51 as an 
emergency AD. This AD required the inspection of the wing lower spar 
cap for cracks on Air Tractor Models AT-501, AT-502, and AT-502A 
airplanes and modification or replacement of any cracked wing lower 
spar cap. Following the release of this AD, the manufacturer evaluated 
the AT-400 and AT-800 series lower spar cap fatigue life.
    AD 2001-10-04: The manufacturer recalculated the fatigue life of 
the wing

[[Page 19995]]

lower spar cap on Air Tractor AT-400, AT-500, and AT-800 series 
airplanes. The manufacturer also received reports of in-service cracks 
on airplanes with hours time-in-service (TIS) less than the published 
safe life. The cracks originated in the wing main spar lower cap at the 
center splice joint outboard \3/8\-inch bolt hole. To address this 
condition, we issued AD 2001-10-04 to lower the safe life for the wing 
lower spar cap on Air Tractor AT-400, AT-500, and AT-800 series 
airplanes. The safe life for the wing lower spar cap ranged from a low 
of 3,000 hours TIS to a high of 13,300 hours TIS depending upon model 
and serial number. This AD superseded AT 2000-14-51 and 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. Operation of the airplane was not allowed if you 
found cracks or you reached TIS limit.
    AD 2001-10-04 R1: We inadvertently included those AT-800 series 
airplanes in the applicability of AD 2001-10-04 that were equipped with 
the factory-supplied computerized fire gate (part number 80540) and 
engaged in full-time firefighting. Consequently, we revised the AD to 
clarify that those airplanes were not affected.
    AD 2002-11-05: In response to AD 2001-10-04 R1, we received a 
comment from the National Transportation Safety Board (NTSB) to 
recommend an eddy-current inspection requirement immediately before 
doing the two-part modification described in Snow Engineering Service 
letter <greek-i>202, revised March 26, 2001. Doing the eddy current 
inspection before the modification makes the crack easier to detect and 
gives the mechanic an area to concentrate on during any post-
modification inspections. We issued AD 2002-11-05 to minimize the 
possibility that a crack existing in a bolt hole before doing the 
modification was still present after doing the modification. Additional 
analysis by the manufacturer also indicated the need to further reduce 
the safe life for certain AT-400 series airplanes and certain AT-500 
series airplanes that either incorporate or have incorporated Marburger 
winglets. These winglets were installed following Supplemental Type 
Certificate (STC) No. SA00490LA. We developed criteria for determining 
what the new safe life would be for airplanes that either incorporate 
or have incorporated these winglets. The safe life was reduced for 
airplanes that either incorporate or have incorporated these winglets 
by a usage factor reduction that is applied to the basic safe life. We 
used this information and issued AD 2002-22-05 to supersede AD 2001-10-
04 R1 and require eddy-current inspections of the wing lower spar cap 
immediately before doing the replacement/modification to detect and 
correct any crack in a bolt hole before it extends to the modified 
center section of the wing. This AD further reduced the safe life for 
certain Models AT-401, AT-401B, AT-402, AT-402A, AT-402B, and AT-501 
airplanes that incorporate or have incorporated Marburger winglets and 
removed the Models AT-502, AT-502A, AT-502B, and AT-503A airplanes from 
the applicability.
    AD 2002-26-05: To address the Models AT-502, AT-502A, AT-502B, and 
AT-503A airplanes that were removed from AD applicability by AD 2002-
11-05, we issued AD 2002-26-05. This AD is still in effect and lowers 
the safe life and requires the eddy-current inspections of the wing 
lower spar cap immediately before doing the replacement/modification. 
This would allow you to detect and correct any crack in a bolt hole 
before it extends to the modified center section of the wing.

What has happened to initiate this AD action?

    The FAA received reports of fatigue cracking found on three AT-400 
series airplanes and on three Model AT-802A airplanes that were below 
the reduced safe life established in AD 2002-11-05. One of the AT-400 
series airplanes had Marburger winglests and the other incident 
airplanes did not. Specifically:
    <bullet> One AT-400 series airplane equipped with winglets cracked 
at 5,340 hours TIS where the reduced safe life was 5,380 hours TIS. A 
second AT-400 series airplane cracked at 3,359 hours TIS where the 
reduced safe life was 4,589 hours TIS. A third AT-400 series airplane 
cracked at 4,176 hours TIS where the reduced safe life was 4,589 hours 
TIS. A third AT-400 series airplane cracked at 4,176 hours TIS where 
the reduced safe life was 4,589 hours TIS, and the cracks were severe 
enough to not allow modification and required immediate wing spar 
replacement; and
    <bullet> One AT-802A airplane cracked at 2,378 hours TIS where the 
reduced safe life was 4,531 hours TIS. A second AT-802A airplane 
cracked at 3,809 hours TIS where the reduced safe life was 4,531 hours 
TIS. A third AT-802A airplane cracked at 4,479 hours TIS where the 
reduced safe life was 4,531 hours TIS.
    Further analysis shows the continued operation of these airplanes 
without inspection and/or modification could severely jeopardize the 
safety of the fleet.

What is the potential impact if the FAA took no action?

    This condition could result in fatigue cracks in the wing lower 
spar cap before the established safe life is reached. Fatigue cracks in 
the wing lower spar cap, if not detected and corrected, could result in 
wing separation and loss of control of the airplane.

Is there service information that applies to this subject?

    Snow Engineering Co. has issued Process Specification <greek-i>197, 
page 1, revised June 4, 2002, pages 2 through 4, dated February 23, 
2001, and page 5, dated May 3, 2002; Process Specification 
<greek-i>204, Rev. C, dated November 16, 2004; Service Letter 
<greek-i>215, page 5, titled ``802 Spar Inspection Holes and Vent Tube 
Mod,'' dated November 19, 2003; Service Letter <greek-i>240, dated 
September 30, 2004; Service letter <greek-i>244, dated April 25, 2005; 
Drawing Number 20975, Sheet 2, Rev. A, dated September 1, 2004; Drawing 
Number 20975, Sheet 3, dated January 6, 2005; and Drawing Number 20995, 
Sheet 2, Rev. C., dated September 28, 2004.
    Snow Engineering Co. has a licensing agreement with Air Tractor 
that allows them to produce technical data to be used for Air Tractor 
products.

What are the provisions of this service information?

    The service letters, process specifications, and drawings include 
procedures for:
    <bullet> Preparing the airplane and the eddy current machine for 
inspection of the lower wing spar caps;
    <bullet> Inspecting the lower wing spar caps for cracks;
    <bullet> Verifying suspected cracks for steel lower wing spar caps;
    <bullet> Installing a web plate and 8-bolt splice block to repair 
cracks and as terminating action for inspections; and
    <bullet> Replacing the spar caps and associated hardware.

The FAA's Determination and Requirements of the AD

What has the FAA decided?

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other Air 
Tractor Model AT-802 and AT-802A airplanes of the same type design. 
Therefore, we are issuing this AD to prevent fatigue cracks from 
occurring in the wing lower spar cap before the originally established 
safe life is reached. Fatigue cracks in the wing lower spar cap, if not 
detected and

[[Page 19996]]

corrected, could result in wing separation and loss of control of the 
airplane. The FAA is also issuing a similar AD on the AT-400 series 
airplanes and revising AD 2002-11-05 to retain the applicability of the 
Model AT-501 airplanes.

What does this AD require?

    This AD requires you to incorporate the actions in the previously 
referenced service information. This AD requires you to use the service 
information described previously to perform these actions.
    This AD changes the inspection interval to address the additional 
cracking found and base the inspection intervals on damage tolerance 
analysis. It also provides a terminating action to the inspection 
requirement and adds serial numbers produced after we issued AD 2002-
11-05. It also retains the safe life for the AT-800 series airplanes 
currently addressed in AD 2002-11-05.
    In preparing this rule, we contacted type clubs and aircraft 
operators to get technical information and information on operational 
and economic impacts. We did not receive any information through these 
contacts. If received, we would have included a discussion of any 
information that may have influenced this action in the rulemaking 
docket.

Comments Invited

Will I have the opportunity to comment before you issue the rule?

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment; however we invite you to submit any written relevant data, 
views, or arguments regarding this AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20591; 
Directorate Identifier 2005-CE-14-AD'' in the subject line of your 
comments. If you want us to acknowledge receipt of your mailed 
comments, send us a self-addressed, stamped postcard with the docket 
number written on it; we will date-stamp your postcard and mail it back 
to you. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify it. If a person contacts us through a non-
written communication, and that contact relates to a substantive part 
of this AD, we will summarize the contact and place the summary in the 
docket. We will consider all comments received by the closing date and 
may amend the AD in light of those comments.

Authority for This Rulemaking

What authority does the FAA have for issuing this rulemaking action?

    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 AD.

Regulatory Findings

Will this AD impact various entities?

    We have determined that 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.

Will this AD involve a significant rule or regulatory action?

    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 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 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-2005-20591; Directorate Identifier 2005-CE-14-AD'' in your 
request.

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 Federal Aviation Administration amends part 39 of the Federal 
Aviation Regulations (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 adding the following new airworthiness 
directive (AD):

2006-08-09 Air Tractor, Inc.: Amendment 39-14565; Docket No. FAA-
2005-20591; Directorate Identifier 2005-CE-14-AD.

When Does This AD Become Effective?

    (a) This AD becomes effective on April 21, 2006.

What Other ADs Are Affected by This Action?

    (b) As of the issuance of this action, AD 2002-11-05 applies to 
Models AT-400, AT-401, AT-401B, AT-402, AT-402A, AT-402B, AT-501, 
AT-802, and AT-802A airplanes. The FAA is revising AD 2002-11-05 to 
remove the AT-400 series and AT-800 series airplanes from the 
applicability. The FAA is also issuing another similar AD on the AT-
400 series airplanes.

What Airplanes Are Affected by This AD?

    (c) This AD affects Model AT-802A airplanes, all serial numbers 
beginning with 802-0001, that are:
    (1) Certificated in any category;
    (2) Engaged in agricultural dispersal operations including those 
airplanes that have been converted between fire fighting and 
agricultural dispersal;
    (3) Not equipped with the factory-supplied computerized fire 
gate (part number 80540); and
    (4) Not engaged in full-time fighting only.

What Is the Unsafe Condition Presented in This AD?

    (d) This AD is the result of fatigue cracking of the wing main 
spar lower cap at the center 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 of the spar cap and lead to wing separation and loss of 
control of the airplane.

What Service Information Must I Use To Do the Actions Required by This 
AD?

    (e) You must use the following Snow Engineering Co. service 
information to do the actions required by this AD:

[[Page 19997]]

    (1) Process Specification <greek-i>197, page 1, revised June 4, 
2002; pages 2 through 4, dated February 23, 2001; and page 5, dated 
May 3, 2002;
    (2) Process Specification <greek-i>204, Rev. C, dated November 
16, 2004;
    (3) Service Letter <greek-i>215, page 5, titled ``802 Spar 
Inspection Holes and Vent Tube Mod,'' dated Novembe 19, 2003;
    (4) Service Letter <greek-i>420, dated September 30, 2004;
    (5) Service Letter <greek-i>244, dated April 25, 2005;
    (6) Drawing Number 20975, Sheet 2, Rev. A, dated September 1, 
2004;
    (7) Drawing Number 20975, Sheet 3, dated January 6, 2005; and
    (8) Drawing Number 20995, Sheet 2, Rev. C., dated September 28, 
2005.

What Must I Do To Address This Problem?

    (f) At the initial inspection time specified in paragraph (f)(2) 
of this AD, do the following:
    (1) For the affected airplanes listed in Table 1 in paragraph 
(f)(2) of this AD, gain access for the required inspection listed 
below by installing cover plates following Service Letter 
<greek-i>215, page 5, titled ``802 Spar Inspection Holes and Vent 
tube mod,'' dated November 19, 2003.
    (2) For the following airplanes, eddy current inspect the center 
splice joint outboard two fastener holes in both the right and left 
wing main spar lower caps for cracks following Process Specification 
<greek-i>197. For these airplanes, use the following wing spar lower 
cap hours time-in-service (TIS) schedule to do the initial and 
repetitive inspections:

                                           Table 1.--Inspection Times
----------------------------------------------------------------------------------------------------------------
                                                                                           Repetitively inspect
              Serial No.                      Condition            Initially inspect:    thereafter at intervals
                                                                                              not to exceed:
----------------------------------------------------------------------------------------------------------------
(i) 802-0001 through 802-0091........  As manufactured........  Upon accumulating 1,700  850 hours TIS.
                                                                 hours TIS or within 50
                                                                 hours TIS after April
                                                                 21, 2006 (the
                                                                 effective date of this
                                                                 AD), whichever occurs
                                                                 later.
(ii) 802-0001 through 802-0091.......  Modified with cold-      If performing the cold-  1,700 hours TIS.
                                        worked fastener holes    working procedure in
                                        following Service        Service Letter <greek-
                                        Letter <greek-i>244.     i>244, it includes the
                                                                 eddy current
                                                                 inspection.
----------------------------------------------------------------------------------------------------------------

    (3) 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 MIL-STD-410; or
    (ii) A person authorized to perform AD work and who has 
completed and passed the Air Tractor, Inc. training course on Eddy 
Current Inspection on wing lower spar caps.
    (g) For all affected airplanes listed in paragraphs (f)(2)(i) 
and (f)(2)(ii) of this AD as terminating action for the inspection 
requirements, you may modify your wing by installing part number (P/
N) 20997-2 web plate and P/N 20985-1 and 20985-2 extended 8-bolt 
splice blocks following Drawing 20995, Sheet 2, and cold-working the 
outboard two fastener holes in both the left and right hand lower 
spar caps at the center splice joint following Service Letter 
<greek-i>240.
    (h) For all affected airplanes listed in paragraphs (f)(2)(i) 
and (f)(2)(ii) of this AD, repair or replace any cracked spar cap 
before further flight after the inspection in which cracks are 
found. For repair or replacement, do whichever of the following that 
applies:
    (1) For cracks that can be repaired by incorporating the 
terminating action specified in paragraph (g) of this AD, do the 
actions in paragraphs (g) of this AD before further flight after the 
inspection in which cracks are found.
    (2) For cracks that cannot be repaired by incorporating the 
terminating action specified in paragraph (g) of this AD, replace 
the lower spar caps and associated parts listed in paragraph (i) of 
this AD before further flight after the inspection in which cracks 
are found.
    (i) For all AT-802 and AT-802A airplanes, upon accumulating the 
hours TIS on the wing spar lower caps listed in paragraph (i)(3) of 
this AD or within 50 hours TIS after April 21, 2006 (the effective 
date of this AD), whichever occurs later, replace the wing main spar 
lower spar caps, the center joint splice blocks and hardware, the 
wing attach angles and hardware, and install the steel web splice 
plate (P/N 21106-1 for serial numbers 0001 through -0091, and P/N 
20094-2 for all serial numbers beginning with 0092), unless already 
done. Replace as follows:
    (1) For airplane serial numbers 802-0001 through 802-0091, 
follow Drawing Number 20975, Sheet 3, and Process Specification 
<greek-i>204.
    (2) For airplane serial numbers beginning with 802-0092, follow 
Drawing Number 20975, Sheet 2, and Process Specification 
<greek-i>204.
    (3) The following presents the safe life and replacements times 
as required in paragraph (i) of this AD:

                Table 2.--Safe Life and Replacement Times
------------------------------------------------------------------------
                                                    Wing spar lower cap
                   Serial No.                            safe-life
------------------------------------------------------------------------
AT-802-0001 through AT-802-0059.................  4,132 hours TIS.
AT-802-0060 through AT-802-0091.................  4,188 hours TIS.
All begining with AT-802-0092...................  8,163 hours TIS.
AT-802A-001 through AT-802A-0059................  4,969 hours TIS.
AT-802A-0060 through AT-802-0091................  4,531 hours TIS.
All beginning with AT-802A-0092.................  8,648 hours TIS.
------------------------------------------------------------------------

    (j) After replacing the wing spar lower caps and hardware, 
installing the web splice plate, and cold working the fastener holes 
by following Drawing Number 20975, Sheet 3 (serial numbers 802-0001 
through 802-0091), or Sheet 2 (all serial numbers beginning with 
802-0092), and Process Specification <greek-i>204, the new safe-life 
for wing spar lower caps is as follows:

[[Page 19998]]



            Table 3.--New Safe Life for Wing Spar Lower Caps
------------------------------------------------------------------------
                                                    Wing spar lower cap
                   Serial No.                            safe-life
------------------------------------------------------------------------
All beginning with AT-802-0001..................  8,163 hours TIS.
All beginning with AT-802A-0001.................  8,648 hours TIS.
------------------------------------------------------------------------

    (k) Report any cracks you find within 10 days after the cracks 
are found or within 10 days after April 21, 2006 (the effective date 
of this AD), whichever occurs later.
    (1) Include in your report the aircraft serial number, aircraft 
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; fascimile: (210) 308-3370.
    (2) The Office of Management and Budget (OMB) approved the 
information collection requirements contained in ths regulation 
under the provisions of the Paperwork Reduction Act and assigned OMB 
Control Number 2120-0056.

May I Request an Alternative Method of Compliance?

    (l) The Manager, Fort Worth Airplane Certification Office, FAA, 
has the authority to aprove alternative methods of compliance for 
this AD, if requested using the procedures found in 14 CFR 39.19. 
For information on any already approved alternative methods of 
compliance or for information pertaining to this AD, contact Andrew 
McAnual, 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.
    (m) AMOCs approved for AD 2001-10-04, AD 2001-10-04 R1, or AD 
2002-11-05 for the Models AT-802 and AT-802A airplanes are not 
considered approved for this AD.

Special Flight Permit

    (n) 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.

Does This AD Incorporate Any Material by References?

    (o) You must do the actions required by this AD following the 
instructions in Snow Engineering Co. Process Specification 
<greek-i>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. Process Specification <greek-i>204, Rev. C, dated November 16, 
2004; Snow Engineering Co. Service Letter <greek-i>215, page 5, 
titled ``802 Spar Inspection Holes and Vent Tube Mod,'' dated 
November 19, 2003; Snow Engineering Co. Service <greek-i>240, dated 
September 30, 2004; Snow Engineering Co. Service Letter 
<greek-i>244, dated April 25, 2005; Snow Engineering Co. Drawing 
Number 20975, Sheet 2, Rev. A, dated September 1, 2004; Snow 
Engineering Co. Drawing Number 20975, Sheet 3, dated January 6, 
2005; and Snow Engineering Co. Drawing Number 20995, Sheet 2, Rev. 
C., dated September 28, 2004. The Director of the Federal Register 
approved the incorporation by reference of this service information 
in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To get a copy 
of this service information, contact Air Tractor, Incorporated, P.O. 
Box 485, Olney, Texas 76374. To review copies of this service 
information, go to the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html or call (202) 741-6030. To 
view the AD docket, go to the Docket Management Facility; US 
Department of Transportation, 400 Seventh Street, SW., Nassif 
Building, Room PL-401, Washington, DC 20590-0001 or on the Internet 
at http://dms.dot.gov. The docket number FAA-2005-20591; Directorate 
Identifier 2005-20591; Directorate Identifier 2005-CE-14-AD.

    Issued in Kansas City, Missouri, on April 10, 2006.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-3613 Filed 4-18-06; 8:45am]
BILLING CODE 4910-13-M


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