[Federal Register: April 28, 2008 (Volume 73, Number 82)]
[Rules and Regulations]
[Page 22795-22800]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28ap08-7]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0476; Directorate Identifier 2008-CE-018-AD;
Amendment 39-15491; AD 2008-09-10]
RIN 2120-AA64
Airworthiness Directives; Air Tractor, Inc. Models AT-300, AT-
301, AT-302, AT-400, and AT-400A Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) to
supersede AD 2003-06-01, which applies to all Air Tractor, Inc. (Air
Tractor) Models AT-300, AT-301, AT-302, and AT-400A airplanes that have
aluminum spar caps; certain Air Tractor Models AT-400 airplanes that
have aluminum spar caps; and all Models AT-300 and AT-301 airplanes
that have aluminum spar caps and are or have been converted to turbine
power. AD 2003-06-01 requires replacing the wing spar lower caps at a
specified safe life limit; allows extending the safe life limit on
certain airplanes if a wing lower spar cap splice rework is done;
allows a limited time of continued operation beyond the safe life limit
provided parts are ordered, the replacement is scheduled, and
repetitive inspections reveal no cracks; and requires a report of any
cracks found during any inspection to the FAA. This AD results from a
recent report of cracks found on a Model AT-301 airplane at hours below
the modification time specified in AD 2003-06-01. Consequently, this AD
retains the wing spar lower cap replacement and reporting requirements
from AD 2003-06-01 and adds a repetitive eddy-current inspection. We
are issuing this AD to detect and correct cracks in the wing centerline
splice joint. If not detected and corrected, these cracks could result
in the wing separating from the airplane during flight.
DATES: This AD becomes effective on May 8, 2008.
On May 8, 2008, the Director of the Federal Register approved the
incorporation by reference of Snow Engineering Co. Service Letter
55, revised October 4, 2004, listed in this AD.
As of April 4, 2003, (68 FR 13221, March 19, 2003), the Director of
the Federal Register approved the incorporation by reference of Snow
Engineering Co. Service Letter 55, revised October 23, 2002,
and Snow Engineering Co. Process Specification Number 197, revised June
4, 2002, listed in this AD.
We must receive any comments on this AD by June 27, 2008.
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; facsimile: (940) 564-5612.
To view the comments to this AD, go to http://www.regulations.gov.
The docket number is FAA-2008-0476; Directorate Identifier 2008-CE-018-
AD.
FOR FURTHER INFORMATION CONTACT: Rob Romero, Aerospace Engineer, FAA,
Fort Worth Airplane Certification Office (ACO), 2601 Meacham Boulevard,
Fort Worth, Texas 76193-0150; telephone: (817) 222-5102; facsimile:
(817) 222-5960; or Andrew McAnaul, Aerospace Engineer, FAA, Fort Worth
ACO (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, Texas
78216; telephone: (210) 308-3365; facsimile: (210) 308-3370.
SUPPLEMENTARY INFORMATION:
Discussion
An incident on an Air Tractor Model AT-400A where the wing
separated from the airplane caused us to issue AD 2002-13-02, Amendment
39-12789 (67 FR 44024, July 1, 2002). Investigation revealed that the
right-hand lower spar cap failed due to fatigue at the \3/8\-inch
outboard bolt, which is located 6.5 inches outboard of the fuselage
centerline.
[[Page 22796]]
The airplanes affected by AD 2002-13-02 have a similar type design
to that of the accident airplane. AD 2002-13-02 required inspecting
(one-time) the wing centerline splice joint for cracks and, if any
crack was found, replacing the affected wing spar lower cap; reporting
the results of the inspection to the FAA; and replacing the wing spar
lower caps after a certain amount of usage.
The inspection reports submitted to the FAA (as required in AD
2002-13-02) revealed a Model AT-400A airplane with a cracked spar cap.
The damage was significant enough to require spar cap replacement.
Based on this damage and the results of the inspection reports, we
determined that the mandatory replacement time for the wing spar lower
cap on the affected turbine engine powered airplanes should be reduced.
This prompted us to issue AD 2003-06-01, Amendment 39-13088 (68 FR
13221, March 19, 2003) to supersede AD 2002-13-02. AD 2003-06-01
requires replacing the wing spar lower caps at a specified safe life
limit; allows extending the safe life limit on certain airplanes if a
wing lower spar cap splice rework is done; allows a limited time of
continued operation beyond the safe life limit provided parts are
ordered, the replacement is scheduled, and repetitive inspections
reveal no cracks; and requires a report of any cracks found during any
inspection to the FAA.
The FAA recently received a report of cracks found on a Model AT-
301 airplane with less hours than the modification time specified in AD
2003-06-01. Based on this incident, we reevaluated the fatigue
management plan for the AT-300 and AT-400 series airplanes that have
aluminum spar caps without part number 20990-1/-2 steel web plate
installed. We have determined that repetitive eddy-current inspections
are needed on these airplanes in order to detect any cracks that may
develop on the wing spar lower cap before reaching the safe life limit.
This condition, if not corrected, could result in the wing
separating from the airplane during flight.
Relevant Service Information
The manufacturer has issued the following service information to
address this situation:
Snow Engineering Co. Service Letter 55, revised
October 23, 2002, which includes procedures and information for doing
the wing lower spar cap splice joint modification rework on all AT-300
and AT-301 series airplanes;
Snow Engineering Co. Service Letter 55, revised
October 4, 2004, which includes revised procedures and information for
doing the wing lower spar cap splice joint modification rework on all
AT-300 and AT-301 series airplanes; and
Snow Engineering Co. Process Specification Number 197,
revised June 4, 2002, which provides procedures for accomplishing eddy
current inspections of the wing lower spar caps.
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
supersedes AD 2003-06-01 with a new AD that:
Requires repetitive eddy-current inspections;
Requires you to replace the wing spar lower caps at
specified times;
Allows you to extend the time for replacement on certain
airplanes if a wing lower spar cap splice rework is done;
Requires you to inspect the wing lower spar cap
immediately prior to modification; and
Requires you to report any cracks found during the
inspections to the FAA.
We are not retaining from AD 2003-06-01 the provision to allow a
limited time of continued operation beyond the safe life limit.
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.
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-2008-0476;
Directorate Identifier 2008-CE-018-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.
Regulatory Findings
We 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.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866;
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); 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.
[[Page 22797]]
We prepared a regulatory evaluation of the estimated costs to
comply with this AD and placed it in the AD docket.
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)
2003-06-01, Amendment 39-13088 (68 FR 13221, March 19, 2003), and by
adding a new AD to read as follows:
2008-09-10 Air Tractor, Inc.: Amendment 39-15491; Docket No. FAA-
2008-0476; Directorate Identifier 2008-CE-018-AD.
Effective Date
(a) This AD becomes effective on May 8, 2008.
Affected ADs
(b) This AD supersedes AD 2003-06-01, Amendment 39-13088.
Applicability
(c) This AD applies to the following airplanes that are
certificated in any category:
(1) Models AT-300, AT-301, AT-302, and AT-400A airplanes, all
serial numbers, that have aluminum spar caps;
(2) Models AT-400 airplanes, serial numbers 400-0244 through
400-0415, that have aluminum spar caps; and
(3) Models AT-300 and AT-301 airplanes, all serial numbers that
have aluminum spar caps and are or have been converted to turbine
power.
Unsafe Condition
(d) This AD is the result of service reports and analysis done
on wing lower spar caps of Air Tractor, Inc. airplanes. The actions
specified by this AD are intended to prevent fatigue cracks from
occurring 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 failure of the spar cap and
lead to wing separation and loss of control.
Compliance
(e) To address this problem, you must do the following, unless
already done:
(1) For all affected airplanes without steel web plates, part
numbers (P/N) 20990-1 or 20990-2, or steel spar caps installed,
eddy-current inspect the left and right wing spar lower cap outboard
holes for cracks following Snow Engineering Co. Process
Specification 197, revised June 4, 2002. Do the inspections
at the following compliance times:
------------------------------------------------------------------------
Initial compliance Repetitive
Affected airplanes time compliance time
------------------------------------------------------------------------
(i) For all airplanes....... Initially inspect Repetitively inspect
upon reaching 3,500 thereafter at
total hours time-in- intervals not to
service (TIS) on exceed 450 hours
the wing spar lower TIS until the wing
cap or within the spar center splice
next 10 hours TIS joint modification
after May 8, 2008 or the required
(the effective date wing spar lower cap
of this AD), replacement. After
whichever occurs each replacement,
later. initially inspect
upon reaching 3,500
total hours TIS on
either wing spar
lower cap, and
repetitively
inspect thereafter
at intervals not to
exceed 450 hours
TIS until the wing
spar center splice
joint modification
or the required
wing spar lower cap
replacement.
(ii) Airplanes that have had You may take credit Repetitively inspect
an eddy-current inspection for that thereafter at
done on the wing spar lower inspection. intervals not-to-
cap within the last 450 Continue with the exceed 450 hours
hours TIS before the required repetitive TIS from the time
effective date of this AD. inspection of the last
intervals. inspection until
the wing spar
center splice joint
modification or the
required wing spar
lower cap
replacement. After
each replacement,
initially inspect
upon reaching 3,500
total hours TIS on
either wing spar
lower cap, and
repetitively
inspect thereafter
at intervals not to
exceed 450 hours
TIS until the wing
spar center splice
joint modification
or the required
wing spar lower cap
replacement.
------------------------------------------------------------------------
(2) For all affected Models AT-300 and AT-301 airplanes with
reciprocating engines, the 450-hour repetitive inspections required
in this AD are terminated after the wing spar center splice joint
modification is incorporated in accordance with paragraph (g) of
this AD or when the wing lower spar caps are replaced. The
replacement specified in paragraph (f)(2) of this AD is still
applicable.
(3) If cracks are found during any inspection required in
paragraphs (e)(1)(i), (e)(1)(ii), or (g)(2) of this AD, replace the
wing lower spar cap before further flight.
(f) Replace each wing lower spar cap in accordance with the
applicable maintenance manual, as follows:
[[Page 22798]]
------------------------------------------------------------------------
Repetitive
Initial replacement replacement/
Affected airplanes compliance time inspection
compliance time
------------------------------------------------------------------------
(1) For all affected Models Upon reaching 5,000 Replace each time
AT-300 and AT-301 airplanes total hours TIS on the safe life limit
with reciprocating engines either wing spar of 5,000 total
and that do not incorporate lower cap or within hours TIS on either
the wing spar center splice the next 25 hours wing spar lower cap
joint modification. TIS after April 4, is reached. After
2003 (the effective each replacement,
date of AD 2003-06- inspect as
01), whichever specified in
occurs later. paragraph (e)(1) of
this AD until the
wing spar center
splice joint
modification or the
required wing spar
lower cap
replacement.
(2) For all affected Models Upon reaching the Replace each time
AT-300 and AT-301 airplanes safe life limit of the safe life limit
with reciprocating engines 7,000 total hours of 7,000 total
that do incorporate the TIS on either wing hours TIS on either
wing spar center splice spar lower cap or wing spar lower cap
joint modification done in within the next 25 is reached. After
accordance paragraph (g) of hours TIS after each replacement,
this AD. April 4, 2003 (the inspect as
effective date of specified in
AD 2003-06-01), paragraph (e)(1) of
whichever occurs this AD until the
later. wing spar center
splice joint
modification or the
required wing spar
lower cap
replacement.
(3) For all affected AT-302, Upon reaching 4,450 Replace each time
AT-400, and AT-400A total hours TIS on the safe life limit
airplanes with aluminum either wing spar of 4,450 total
spar caps; and all affected lower cap or within hours TIS on the
Models AT-300 and AT-301 the next 25 hours wing spar lower cap
airplanes with aluminum TIS after April 4, is reached. After
spar caps that are or have 2003 (the effective each replacement
ever been converted to date of AD 2003-06- inspect as
turbine power. 01), whichever specified in
occurs later. paragraph (e)(1) of
this AD until the
required wing spar
lower cap
replacement.
------------------------------------------------------------------------
(g) For airplanes specified in paragraph (f)(1) of this AD, you
may extend the safe life limit of the wing spar lower cap to 7,000
hours TIS by incorporating the wing spar center splice joint
modification following the procedures in Snow Engineering Co.
Service Letter 55, revised October 23, 2002; or Snow
Engineering Co. Service Letter 55, revised October 4, 2004,
with the following requirements:
(1) This modification must be done no earlier than 4,600 total
hours TIS on the wing spar lower cap and no later than 5,000 total
hours TIS on the wing spar lower cap.
(2) Immediately before incorporating the modification, you must
do an eddy-current inspection for cracks following Snow Engineering
Co. Process Specification 197, revised June 4, 2002.
(3) After each replacement, inspect as specified in paragraph
(e)(1) of this AD until the wing spar center splice joint
modification or the required wing spar lower cap replacement.
(h) Eddy-current inspections required by this AD must be done by
one of the following:
(1) 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
(2) 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.
Note 1: We are not retaining from AD 2003-06-01 the provision to
allow a limited time of continued operation beyond the safe life
limit provided parts are ordered, the replacement is scheduled, and
repetitive inspections reveal no cracks. That provision was put in
AD 2003-06-01 to prevent airplanes from being inadvertently grounded
if parts were not available. If parts availability were to ever
become a problem in the future, the owner/operator could request an
alternative method of compliance following the procedures in 14 CFR
39.19 and this AD.
(i) Report the results of any inspection required by this AD
where cracks are found to the FAA.
(1) Submit this report within 10 days after the inspection.
(2) Use the form (Figure 1 of this AD) and submit it to FAA,
Fort Worth Airplane Certification Office (ACO), 2601 Meacham
Boulevard, Fort Worth, Texas 76193-0150; telephone: (817) 222-5156;
facsimile: (817) 222-5960.
(3) 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 et seq.) and assigned OMB Control Number 2120-0056.
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[[Page 22799]]
[GRAPHIC] [TIFF OMITTED] TR28AP08.001
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Alternative Methods of Compliance (AMOCs)
(j) The Manager, Fort Worth ACO, 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: Rob Romero, Aerospace
Engineer, FAA, Fort Worth ACO, 2601 Meacham Boulevard, Fort Worth,
Texas 76193-0150; telephone: (817) 222-5102; facsimile: (817) 222-
5960; or 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. 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.
(k) AMOCs approved for AD 2003-06-01 are approved for this AD.
[[Page 22800]]
Special Flight Permit
(l) Under 14 CFR part 39.23, we are limiting the special flight
permits for this AD by the following conditions:
(1) Operate only 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.
Material Incorporated by Reference
(m) You must use Snow Engineering Co. Service Letter
55, revised October 23, 2002; Snow Engineering Co. Service
Letter 55, revised October 4, 2004; and Snow Engineering
Co. Process Specification Number 197, revised June 4, 2002, 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
55, revised October 4, 2004, under 5 U.S.C. 552(a) and 1
CFR part 51.
(2) On April 4, 2003, (68 FR 13221, March 19, 2003), the
Director of the Federal Register approved the incorporation by
reference of Snow Engineering Co. Service Letter 55,
revised October 23, 2002, and Snow Engineering Process Specification
Number 197, revised June 4, 2002.
(3) For service information identified in this AD, contact
Tractor, Inc., P.O. Box 485, Olney, Texas 76374.
(4) You may review copies at the FAA, Central Region, Office of
the Regional Counsel, 901 Locust, Kansas City, Missouri 64106; or 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 April 18, 2008.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-9058 Filed 4-25-08; 8:45 am]
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