Document ID: FAA-2009-0778-0006
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Twin Commander Aircraft LLC Models 690, 690A, and 690B Airplanes
Posted Date: 2009-12-04T05:00Z

[Federal Register: December 4, 2009 (Volume 74, Number 232)]
[Rules and Regulations]               
[Page 63565-63568]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04de09-7]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0778; Directorate Identifier 2009-CE-040-AD; 
Amendment 39-16119; AD 2009-25-02]
RIN 2120-AA64

 
Airworthiness Directives; Twin Commander Aircraft LLC Models 690, 
690A, and 690B Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Twin Commander Aircraft LLC Models 690, 690A, and 690B airplanes. This 
AD requires you to inspect between the surface of the left-hand (LH) 
and right-

[[Page 63566]]

hand (RH) upper wing skins and the engine mount beam support straps for 
any signs of corrosion, replace the upper steel straps with parts of 
improved design, and modify both wings. This AD results from reports 
that corrosion was found between the mating surfaces of the wing upper 
skin surface and the engine mount beam support straps. We are issuing 
this AD to detect and correct corrosion on the engine mount beam 
support straps and the upper wing skins, which could result in failure 
of the engine mount beam support straps. This failure could lead to 
loss of the engine and possible loss of control of the airplane.

DATES: This AD becomes effective on January 8, 2010.
    On January 8, 2010, the Director of the Federal Register approved 
the incorporation by reference of certain publications listed in this 
AD.

ADDRESSES: To get the service information identified in this AD, 
contact Twin Commander Aircraft LLC, 18933-59th Avenue, NE., Suite 115, 
Arlington, WA 98223, telephone: (360) 435-9797; fax: (360) 435-1112; 
Internet: http://www.twincommander.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-2009-0778; 
Directorate Identifier 2009-CE-040-AD.

FOR FURTHER INFORMATION CONTACT: Vince Massey, Aerospace Engineer, FAA, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone: (425) 917-6475; fax: (425) 917-6590; 
e-mail: vince.massey@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    On August 21, 2009, 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 Twin Commander Aircraft LLC Models 690, 690A, 
and 690B airplanes. This proposal was published in the Federal Register 
as a notice of proposed rulemaking (NPRM) on August 28, 2009 (74 FR 
44308). The NPRM proposed to require you to inspect between the surface 
of the LH and RH upper wing skins and the engine mount beam support 
straps for any signs of corrosion, replace the upper steel straps with 
parts of improved design, and modify both wings.

Comments

    We provided the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and FAA's response to each comment:

Comment Issue: Extend Compliance Time

    Michael Curtis Pidek, William I. Smith, and Tom Bayer all state 
that with 275 airplanes affected by this AD and only 15 service centers 
available to do the actions required in this AD, there is not enough 
time to comply with the AD.
    All three commenters request an extension of the compliance time to 
allow enough time for the service centers to schedule the work without 
grounding airplanes until the work can be done.
    We do not agree with the commenters. Over 65 airplanes are already 
in compliance with this AD. We have consulted with Twin Commander 
Aircraft LLC and they have covered this issue with the service centers. 
The service centers know how much work is required since they have 
already done the work on over 65 of the affected airplanes. The service 
centers plan on using multiple teams to work on several airplanes at 
the same time. They have confirmed they can perform the actions 
required in this AD in the compliance time as proposed.
    Part of the alternative method of compliance (AMOC) provisions of 
14 CFR 39.19 is an extension of the compliance time provided a level of 
safety acceptable to the FAA is met. The FAA will review any AMOCs of 
this nature on a case-by-case basis. If we determine the proposal 
presents an acceptable level of safety, we will approve it as an AMOC 
to the AD.
    We are not changing the final rule AD action based on these 
comments.

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:
     Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.

Costs of Compliance

    We estimate that this AD will affect 275 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
----------------------------------------------------------------------------------------------------------------
80 work-hours x $80 per hour = $6,400........  Not applicable.................          $6,400       $1,760,000
----------------------------------------------------------------------------------------------------------------

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

                     Short Modification--Option A *
------------------------------------------------------------------------
                                                          Total cost per
            Labor cost                  Parts cost         airplane per
                                                               side
------------------------------------------------------------------------
250 work-hours x $80 per hour =    $9,170 per kit per           $29,170
 $20,000 per side.                  side.
------------------------------------------------------------------------

[[Page 63567]]

                     Middle Modification--Option B *
------------------------------------------------------------------------
                                                          Total cost per
            Labor cost                  Parts cost         airplane per
                                                               side
------------------------------------------------------------------------
280 work-hours x $80 per hour =    $9,170 per kit per           $31,570
 $22,400 per side.                  side.
------------------------------------------------------------------------

                      Long Modification--Option C *
------------------------------------------------------------------------
                                                          Total cost per
            Labor cost                  Parts cost         airplane per
                                                               side
------------------------------------------------------------------------
320 work-hours x $80 per hour =    $9,170 per kit per           $34,770
 $25,600 per side.                  side.
------------------------------------------------------------------------

    Note: * Depending on airplane configuration, airplanes with 
rectangular plates will need the Plate and Hardware Kit (SB237-4) at 
$2,090 per side. Labor to install this kit is included in Options A, 
B, and C.

                    Strap Only Replacement--Option D
------------------------------------------------------------------------
                                                          Total cost per
            Labor cost                  Parts cost         airplane per
                                                               side
------------------------------------------------------------------------
75 work-hours x $80 per hour =     $6,190 per strap per         $12,190
 $6,000 per side.                   side.
------------------------------------------------------------------------

    We estimate the following costs to do the installation of access 
holes:

----------------------------------------------------------------------------------------------------------------
                                                                                 Total cost per   Total cost on
                          Labor cost                              Parts cost        airplane      U.S. operators
----------------------------------------------------------------------------------------------------------------
30 work-hours x $80 per hour = $2,400........................          $1,293           $3,693       $1,015,575
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do the wing fastener 
modification:

----------------------------------------------------------------------------------------------------------------
                                                                                 Total cost per   Total cost on
                          Labor cost                              Parts cost        airplane      U.S. operators
----------------------------------------------------------------------------------------------------------------
8.5 work-hours x $80 per hour = $680.........................            $250             $930         $255,750
----------------------------------------------------------------------------------------------------------------

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-2009-0778; Directorate Identifier 2009-CE-040-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,

[[Page 63568]]

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 a new AD to read as follows:

2009-25-02 Twin Commander Aircraft LLC: Amendment 39-16119; Docket 
No. FAA-2009-0778; Directorate Identifier 2009-CE-040-AD.

Effective Date

    (a) This AD becomes effective on January 8, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the following airplane models and serial 
numbers that are certificated in any category:

------------------------------------------------------------------------
              Models                         Serial Nos. (S/Ns)
------------------------------------------------------------------------
690...............................  All S/Ns
690A..............................  All S/Ns except 11195 and 11279.
690B..............................  All S/Ns except 11361, 11383, 11527,
                                     and 11536.
------------------------------------------------------------------------

Unsafe Condition

    (d) This AD results from reports that corrosion was found 
between the mating surfaces of the wing upper skin surface and the 
engine mount beam support straps. We are issuing this AD to detect 
and correct corrosion on the engine mount beam support straps and 
upper wing skins, which could result in failure of the engine mount 
beam support straps. This failure could lead to loss of the engine 
and possible loss of control of the airplane.

Compliance

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

------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Inspect between the       Within the next 150   Follow Twin
 surface of the left-hand      hours time-in-        Commander Aircraft
 (LH) and right-hand (RH)      service after         LLC Alert Service
 upper wing skins and the      January 8, 2010       Bulletin No. 237,
 engine mount beam support     (the effective date   dated May 13, 2005,
 straps for any signs of       of this AD) or        pages 1 through 14.
 corrosion and determine the   within the next 12
 extent of any corrosion       months after
 found.                        January 8, 2010
                               (the effective date
                               of this AD),
                               whichever occurs
                               first.
(2) Install modification      Before further        Follow the
 access holes in the LH and    flight after the      Accomplishment
 RH lower wing skins.          inspection required   Instructions, steps
                               in paragraph (e)(1)   1 through 4 and 6
                               of this AD.           through 9, of Twin
                                                     Commander Aircraft
                                                     Corporation Custom
                                                     Kit No. 150, dated
                                                     July 8, 1994, as
                                                     specified in Twin
                                                     Commander Aircraft
                                                     LLC Alert Service
                                                     Bulletin No. 237,
                                                     dated May 13, 2005.
(3) If corrosion damage is    Before further        Follow Twin
 found during the inspection   flight after the      Commander Aircraft
 required in paragraph         inspection required   LLC Alert Service
 (e)(1) of this AD, perform    in paragraph (e)(1)   Bulletin No. 237,
 necessary modification.       of this AD.           dated May 13, 2005,
                                                     Part II, Options A,
                                                     B, or C, on pages
                                                     15 through 29 and
                                                     31.
(4) If corrosion damage is    Before further        Follow Twin
 not found during the          flight after the      Commander Aircraft
 inspection required in        inspection required   LLC Alert Service
 paragraph (e)(1) of this      in paragraph (e)(1)   Bulletin No. 237,
 AD, do the upper steel        of this AD.           dated May 13, 2005,
 strap replacements.                                 Part II, Option D,
                                                     on pages 30 and 31.
(5) Install additional wing   Before further        Follow Gulfstream
 fasteners on the LH and RH    flight after the      American
 wing.                         inspection required   Corporation Service
                               in paragraph (e)(1)   Bulletin No. 182,
                               of the AD.            dated March 2,
                                                     1981.
------------------------------------------------------------------------

    Note: Although not required by this AD, we highly recommend 
compliance with Twin Commander Aircraft Corporation Service Bulletin 
No. 217, Revision No. 1, dated May 26, 1993, Engine Nacelle Firewall 
Reinforcement; and Twin Commander Aircraft LLC Alert Service 
Bulletin No. 239, dated February 13, 2006, Outboard Flap--Inboard 
Hinge Inspection & Reinforcement.

Alternative Methods of Compliance (AMOCs)

    (f) The Manager, Seattle Aircraft Certification Office (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: Vince Massey, Aerospace Engineer, FAA, Seattle ACO, 1601 Lind 
Avenue, SW, Renton, Washington 98057-3356; telephone: (425) 917-
6475; fax: (425) 917-6590; email: vince.massey@faa.gov. 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

    (g) You must use Twin Commander Aircraft LLC Alert Service 
Bulletin No. 237, dated May 13, 2005; Twin Commander Aircraft 
Corporation Custom Kit No. 150, dated July 8, 1994; and Gulfstream 
American Corporation Service Bulletin No. 182, dated March 2, 1981, 
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 Twin 
Commander Aircraft LLC, 18933--59th Avenue, NE., Arlington, WA 
98223, telephone: (360) 435-9797; fax: (360) 435-1112; Internet: 
http://www.twincommander.com.
    (3) You may review copies of the service information 
incorporated by reference for this AD at the FAA, Central Region, 
Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 
64106. For information on the availability of this material at the 
Central Region, call (816) 329-3768.
    (4) You may also review copies of the service information 
incorporated by reference for this AD at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call (202) 741-6030, or go to: http://
www.archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.

    Issued in Kansas City, Missouri, on November 20, 2009.
Margaret Kline,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-28548 Filed 12-3-09; 8:45 am]

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