Airworthiness Directives; Thrush Aircraft, Inc. Model S2R Series Airplanes

[Federal Register Volume 72, Number 241 (Monday, December 17, 2007)]
[Rules and Regulations]
[Pages 71204-71206]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-24218]



[[Page 71204]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28432; Directorate Identifier 2007-CE-051-AD; 
Amendment 39-15303; AD 2007-26-01]
RIN 2120-AA64


Airworthiness Directives; Thrush Aircraft, Inc. Model S2R Series 
Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Thrush Aircraft, Inc. (Thrush) Model S2R series airplanes. This AD 
requires you to do repetitive visual inspections of the vertical and 
horizontal stabilizer attach fitting, attach fitting bolts, and the 
vertical fin aft spar for cracks or corrosion. This AD also requires 
immediate replacement of the vertical and horizontal stabilizer attach 
fittings and attach fitting bolts if cracked or corroded parts are 
found, and the inspection of the vertical fin aft spar with repair or 
replacement if cracks or corrosion are found. This AD requires the 
eventual replacement of the vertical and horizontal stabilizer attach 
fittings and attach fitting bolts if no corrosion or cracks are found 
as terminating action for the repetitive inspections. This AD results 
from reports of cracks in the empennage of Thrush S2R series airplanes. 
We are issuing this AD to detect and correct these cracks, which could 
cause the vertical stabilizer to lose structural integrity. This 
failure could lead to loss of control.

DATES: This AD becomes effective on January 22, 2008.
    On January 22, 2008, the Director of the Federal Register approved 
the incorporation by reference of certain publications listed in this 
AD.

ADDRESSES: For service information identified in this AD, contact 
Thrush Aircraft, Inc., P.O. Box 3149, 300 Old Pretoria Road, Albany, 
Georgia 31706-3149; telephone: 229-883-1440; facsimile: 229-436-4856; 
or on the Internet at: www.thrushaircraft.com.
    To view the AD docket, go to U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue, SE., Washington, DC 20590, or on the Internet at 
http://www.regulations.gov. The docket number is FAA-2007-28432; 
Directorate Identifier 2007-CE-051-AD.

FOR FURTHER INFORMATION CONTACT ONE OF THE FOLLOWING:

--Cindy Lorenzen, Aerospace Engineer, ACE-115A, Atlanta Aircraft 
Certification Office, One Crown Center, 1895 Phoenix Blvd., Suite 450, 
Atlanta, Georgia 30349; telephone: (770) 703-6078; fax: (770) 703-6097; 
e-mail: [email protected]; or
--Mike Cann, Aerospace Engineer, ACE-117A, Atlanta Aircraft 
Certification Office, One Crown Center, 1895 Phoenix Blvd., Suite 450, 
Atlanta, Georgia 30349; telephone: (770) 703-6038; facsimile: (770) 
703-6097; e-mail: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    On July 26, 2007, 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 certain S2R series airplanes. This proposal was 
published in the Federal Register as a notice of proposed rulemaking 
(NPRM) on July 26, 2007 (72 FR 41042). The NPRM proposed to require 
repetitive visual inspections of the vertical and horizontal stabilizer 
attach fitting, attach fitting bolts, and the vertical fin aft spar for 
corrosion or cracks. The NPRM also proposed to require immediate 
replacement of the vertical and horizontal stabilizer attach fittings 
and attach fitting bolts if cracked or corroded parts are found, and 
inspection of the vertical fin aft spar with repair or replacement if 
cracks or corrosion are found. This AD requires the eventual 
replacement of the vertical and horizontal stabilizer attach fittings 
and attach fitting bolts if no corrosion or cracks are found as 
terminating action for the repetitive inspections.

Comments

    We provided the public the opportunity to participate in developing 
this AD. We received no comments on the proposal or on the 
determination of the cost to the public.

Conclusion

    We have carefully reviewed the available data and determined that 
air safety and the public interest require adopting the AD as proposed 
except for minor editorial corrections. We have determined that these 
minor corrections:
    <bullet> Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM.

Costs of Compliance

    We estimate that this AD affects 910 airplanes in the U.S. 
registry.
    We estimate the following costs to do the inspection:

----------------------------------------------------------------------------------------------------------------
                                                                               Total cost  per    Total cost on
                 Labor cost                             Parts cost                airplane       U.S. operators
----------------------------------------------------------------------------------------------------------------
8 work-hours x $80 per hour = $640..........  Not applicable................             $640          $582,400
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements of 
the vertical fin aft spar that would be required based on the results 
of the inspection. We have no way of determining the number of 
airplanes that may need this replacement:

------------------------------------------------------------------------
                                                          Total cost per
              Labor cost                   Parts cost        airplane
------------------------------------------------------------------------
12 work-hours x $80 per hour = $960...          $3,800           $4,760
------------------------------------------------------------------------

    We estimate the following costs to replace the vertical and 
horizontal stabilizer attach fittings and attachment bolt:

[[Page 71205]]



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                                                                               Total cost  per    Total cost on
                         Labor cost                              Parts cost        airplane      U.S. operators
----------------------------------------------------------------------------------------------------------------
30 work-hours x $80 per hour = $2,400.......................          $1,550           $3,950        $3,594,500
----------------------------------------------------------------------------------------------------------------

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 AD.

Regulatory Findings

    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.
    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 ``Docket 
No. FAA-2007-28432; Directorate Identifier 2007-CE-051-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. FAA amends Sec.  39.13 by adding the following new AD:

2007-26-01 Thrush Aircraft, Inc.: Amendment 39-15303; Docket No. 
FAA-2007-28432; Directorate Identifier 2007-CE-051-AD.

Effective Date

    (a) This AD becomes effective on January 22, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the following airplane models and serial 
numbers that are certificated in any category and are equipped with 
metal empennage part numbers (P/N) 40220 or 95400 (applies to serial 
numbers with or without a ``DC'' suffix):

------------------------------------------------------------------------
               Model                             Serial Nos.
------------------------------------------------------------------------
(1) S2R...........................  1416R through 5100R.
(2) S2R-R1340.....................  R1340-001 through R1340-035.
(3) S2R-R1820.....................  R1820-001 through R1820-036.
(4) S2R-T11.......................  T11-001 through T11-005.
(5) S2R-T15.......................  T15-001 through T15-044 and T27-001
                                     through T27-044.
(6) S2R-T34.......................  6000 through 6049, T34-001 through
                                     T34-279, T36-001 through T36-279,
                                     T41-001 through T41-279, and T42-
                                     001 through T42-279.
(7) S2RHG-T34.....................  T34HG-101 through T34HG-107.
(8) S2R-T45.......................  T45-001 through T45-015.
(9) S2R-T65.......................  T65-001 through T65-018.
(10) S2RHG-T65....................  T65-001 through T65-018 and T65HG-
                                     011 through T65HG-019.
(11) S2R-G1.......................  G1-101 through G1-115.
(12) S2R-G5.......................  G5-101 through G5-105.
(13) S2R-G6.......................  G6-101 through G6-155.
(14) S2R-G10......................  G10-101 through G10-168.
(15) S2R-T660.....................  T660-101 through T660-120.
------------------------------------------------------------------------

Unsafe Condition

    (d) This AD results from reports of cracks in the empennage of 
Thrush Aircraft, Inc., S2R series airplanes. We are issuing this AD 
to detect and correct these cracks, which could cause the vertical 
stabilizer to lose structural integrity. This condition could lead 
to loss of control.

Compliance

    (e) To address this problem, you must do the following, unless 
already done:

[[Page 71206]]



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                  Actions                                Compliance                        Procedures
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(1) Perform a visual inspection of the       Within the next 50 hours time-in-  Follow Thrush Aircraft, Inc.
 vertical stabilizer attach fitting (P/N      service (TIS) after January 22,    Service Bulletin No. SB-AG-45,
 40301-7), the horizontal stabilizer attach   2008 (the effective date of this   Revision B, dated June 1, 2007.
 fitting (P/N 40303-1/-4/-7 or 95267-1),      AD) and repetitively thereafter
 attachment bolt (P/N NAS1105-68), and the    at intervals not to exceed 100
 vertical fin aft spar (P/N 40261-24 or P/N   hours TIS.
 95253-1) for corrosion and cracks.
(2) If corrosion or cracks are found in P/N  Before further flight after any    Follow Thrush Aircraft, Inc.
 40301-7, 40303-1/-4/-7, 95267-1, NAS1105-    inspection where corrosion or      Service Bulletin No. SB-AG-45,
 68, 40261-24, or 95253-1 during any          cracks are found. This action      Revision B, dated June 1, 2007.
 inspection required in paragraph (e)(1) of   terminates the repetitive
 this AD:                                     inspections required in
(i) Replace the vertical stabilizer attach    paragraph (e)(1) of this AD.
 fitting with new P/N 95266-3; the
 horizontal stabilizer attach fitting with
 new P/N 95267-5; and the attachment bolt
 with NAS6207-68; and.
(ii) If corrosion or cracks are found in
 the P/N 40261-24 or P/N 95253-1 vertical
 fin aft spar, repair in accordance with
 Thrush SB-AG-45, Revision B, or replace
 with a new P/N 40261-24 or new P/N 95253-1.
(3) If no corrosion or cracks are found in   Within the next 2,000 hours TIS    Follow Thrush Aircraft, Inc.
 P/N 40301-7, 40303-1/-4/-7, 95267-1,         after January 22, 2008 (the        Service Bulletin No. SB-AG-45,
 NAS1105-68, 40261-24, or 95253-1 during      effective date of this AD) or      Revision B, dated June 1, 2007.
 any inspection required in paragraph         within 2 years after January 22,
 (e)(1) of this AD:                           2008 (the effective date of this
(i) Replace the vertical stabilizer attach    AD), whichever occurs first.
 fitting with new P/N 95266-3; the            This action terminates the
 horizontal stabilizer attach fitting with    repetitive inspections required
 new P/N 95267-5; and the attachment bolt     in paragraph (e)(1) of this AD.
 with NAS6207-68; and.
(ii) Perform a visual inspection of the
 vertical fin aft spar (P/N 40261-24 or P/N
 95253-1) for corrosion and cracks, and.
(iii) If corrosion or cracks are found in
 the P/N 40261-24 or P/N 95253-1 vertical
 fin aft spar, repair in accordance with
 Thrush SB-AG-45, Revision B, or replace
 with a new P/N 40261-24 or new P/N 95253-1.
----------------------------------------------------------------------------------------------------------------

Special Flight Permit

    (f) Under 14 CFR part 39.23, we are limiting the special flight 
permits authorized for this AD to ferry aircraft to a maintenance 
facility for inspection by the following conditions:
    (1) Hopper must be empty;
    (2) Vne reduced to 126 m.p.h. (109 knots); and
    (3) No flight into known turbulence.

Alternative Methods of Compliance (AMOCs)

    (g) The Manager, 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: Cindy Lorenzen, Aerospace Engineer, ACE-
115A, Atlanta Aircraft Certification Office, One Crown Center, 1895 
Phoenix Blvd., Suite 450, Atlanta, GA 30349; telephone: (770) 703-
6078; facsimile: (770) 703-6097; e-mail: [email protected]; or 
Mike Cann, Aerospace Engineer, ACE-117A, Atlanta Aircraft 
Certification Office, One Crown Center, 1895 Phoenix Blvd., Suite 
450, Atlanta, Georgia 30349; telephone: (770) 703-6038; facsimile: 
(770) 703-6097; e-mail: [email protected]. 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.

Material Incorporated by Reference

    (h) You must use Thrush Aircraft, Inc. Service Bulletin No. SB-
AG-45, Revision B, dated June 1, 2007, 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 this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Thrush Aircraft, Inc., P.O. Box 3149, 300 Old Pretoria Road, Albany, 
Georgia 31706-3149; telephone: 229-883-1440; facsimile: 229-436-
4856; or on the Internet at: http://www.thrushaircraft.com.
    (3) 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 December 10, 2007.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-24218 Filed 12-14-07; 8:45 am]
BILLING CODE 4910-13-P

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