
[Federal Register Volume 78, Number 93 (Tuesday, May 14, 2013)]
[Rules and Regulations]
[Pages 28125-28128]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-10498]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0393; Directorate Identifier 2012-CE-025-AD; 
Amendment 39-17446; AD 2013-09-05]
RIN 2120-AA64


Airworthiness Directives; Twin Commander Aircraft LLC Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Twin Commander Aircraft LLC Models 690, 690A, and 690B airplanes. This 
AD requires inspection for cracking of the outer fuselage attachments, 
the lower wing main spar, the vertical channels, the upper picture 
window channels, aft cabin pressure web, external wing to fuselage 
fillets, and fasteners; repair or replacement of damaged parts as 
necessary; and modification of the structure with reinforced parts. 
This AD

[[Page 28126]]

was prompted by cracks found in the upper picture window frame 
channels, left- and right-hand wing main spar frame support channels, 
and aft pressure bulkhead web. This condition, if not corrected, could 
result in structural failure of the airplane. We are issuing this AD to 
correct the unsafe condition on these products.

DATES: This AD is effective May 29, 2013.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of May 29, 2013.
    We must receive comments on this AD by June 28, 2013.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     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.
    For service information identified in this AD, contact Twin 
Commander Aircraft LLC; 1176 Telecom Drive, Creedmoor, NC 27522; 
telephone: (360) 403-0258; email: gpence@twincommander.com; Internet: 
http://www.twincommander.com. You may review copies of the referenced 
service information at the FAA, Small Airplane Directorate, 901 Locust, 
Kansas City, Missouri 64106. For information on the availability of 
this material at the FAA, call (816) 329-4148.

Examining the AD Docket

    You may examine the AD docket 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 AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Office (phone: 800-647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

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

SUPPLEMENTARY INFORMATION:

Discussion

    We were notified of cracks found in the left and right wing main 
spar frame support channels, the aft pressure bulkhead web, and the 
left and right picture window upper frame channels of a Twin Commander 
Aircraft LLC Model 690B airplane. Nineteen airplanes were inspected 
with one having severe cracking in the left and right wing main spar 
frame support channels, the aft pressure bulkhead web, and the left and 
right picture window upper frame channels. Five other of the inspected 
airplanes had similar but less severe damage. This condition, if not 
corrected, could result in structural failure of the aircraft.

Relevant Service Information

    We reviewed Twin Commander Aircraft LLC Service Bulletin 241, dated 
September 26, 2012. The service information describes procedures for 
access, disassembly, and inspecting the outer fuselage attachments, the 
lower wing main spar, the vertical channels, the upper picture window 
channels, aft cabin pressure web, external wing to fuselage fillets, 
and fasteners for cracking. The service information also describes 
procedures for modifying the structure with reinforced parts and 
reassembly.

FAA's Determination

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

AD Requirements

    This AD requires inspection for cracking of the outer fuselage 
attachments, the lower wing main spar, the vertical channels, the upper 
picture window channels, aft cabin pressure web, external wing to 
fuselage fillets, and fasteners; repair or replacement of damaged parts 
as necessary; and modification of the structure with reinforced parts.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because 
cracking in the upper picture window frame channels, left- and right-
hand wing main spar frame support channels, and/or aft pressure 
bulkhead web could result in structural failure of the aircraft. 
Therefore, we find that notice and opportunity for prior public comment 
are impracticable and that good cause exists for making this amendment 
effective in less than 30 days.

Comments Invited

    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 send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the docket number FAA-2013-0393 and 
Directorate Identifier 2012-CE-025-AD at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this AD. We will 
consider all comments received by the closing date and may amend this 
AD because 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 about this AD.

Costs of Compliance

    We estimate that this AD affects 280 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

[[Page 28127]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
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Disassembly, inspection, and            584 work-hours x $85 per          $8,450         $58,090     $16,265,200
 modification.                           hour = $49,640.
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    The scope of damage found in the required inspection could vary 
significantly from airplane to airplane. We have no way of determining 
how much damage may be found on each airplane or the cost to repair 
damaged parts on each airplane. The damage could be as minor as 
replacing rivets or fasteners or as extensive as a major wing/fuselage 
repair or replacement.

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

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA) 
establishes as a principle of regulatory issuance that agencies shall 
endeavor, consistent with the objective of the rule and of applicable 
statutes, to fit regulatory and informational requirements to the scale 
of the businesses, organizations, and governmental jurisdictions 
subject to regulation.
    To achieve that principle, the RFA requires agencies to solicit and 
consider flexible regulatory proposals and to explain the rationale for 
their actions. The RFA covers a wide-range of small entities, including 
small businesses, not-for-profit organizations, and small governmental 
jurisdictions.
    Agencies must perform a review to determine whether a proposed or 
final rule will have a significant economic impact on a substantial 
number of small entities. In accordance with Section 608 of the 
Regulatory Flexibility Act, an agency head may waive or delay 
completion of some or all of the requirements of Section 603 by 
providing a written finding that this final rule is being promulgated 
in response to an emergency that makes compliance or timely compliance 
with the provisions of Section 603 impracticable.
    We are performing a review to determine whether this final rule AD 
action will have a significant economic impact on a substantial number 
of small entities. However, the immediate safety of flight conditions 
of this AD action make compliance with the provisions of Section 603 
impracticable. Our justification for immediate adoption of this rule, 
and therefore of impracticability, is stated in FAA's Justification and 
Determination of the Effective Date. After we determine whether this 
final rule AD action has a significant economic impact on a substantial 
number of small entities or not, we will publish in the Federal 
Register our determination and, if required, our final regulatory 
flexibility analysis.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    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 adding the following new airworthiness 
directive (AD):

2013-09-05 Twin Commander Aircraft LLC: Amendment 39-17446 ; Docket 
No. FAA-2013-0393; Directorate Identifier 2012-CE-025-AD.

(a) Effective Date

    This AD is effective May 29, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to the following Twin Commander Aircraft LLC 
airplanes, certificated in any category:
    (1) Model 690, all serial numbers except 11057;
    (2) Model 690A, all serial numbers except 11104, 11106, 11129, 
11134, 11146, 11159, 11173, 11192, 11220, 11237, 11252, 11263, 
11280, 11287, 11298, 11303, 11317, 11339, and 11341; and
    (3) Model 690B, all serial numbers except 11383, 11384, 11401, 
and 11436.
    (4) Aircraft equipped with AVIADESIGN, Inc. STC No. SA5740NM 
(You may find information on STC No. SA5740NM at Internet: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/FEC5B7544E15F14C85256CC200122B19?OpenDocument&Highlight=sa5740nm) 
are not compatible with the modifications contained in Twin 
Commander Aircraft LLC Service Bulletin 241, dated September 26, 
2012. When an airplane has been modified, altered, or repaired in 
the area addressed by the AD action, according to 14 CFR part 39.15, 
the AD action still applies to that airplane. Following 14 CFR 
39.19, the owner/operator of that airplane must request approval 
from the FAA for an alternative method of compliance (AMOC) 
following the instructions in paragraph (j) of this AD.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 53; Fuselage.

(e) Unsafe Condition

    This AD was prompted by cracks found in the upper picture window 
frame channels, left- and right-hand wing main spar frame support 
channels, and aft pressure bulkhead web. This condition, if not 
corrected, could result in structural failure of the airplane. We 
are issuing this AD to correct the unsafe condition on these 
products.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Inspection

    (1) Inspect the airplane structural components, at the 
compliance times specified in paragraphs (g)(1)(i) through 
(g)(1)(iv) of this AD following Part I of Twin Commander Aircraft 
LLC Service Bulletin 241, September 26, 2012:
    (i) For airplanes with 10,000 or more hours time-in-service 
(TIS), inspect within the next 30 days after the effective date of 
this AD.

[[Page 28128]]

    (ii) For airplanes with 7,500 through 9,999 hours TIS, inspect 
within the next 60 days after the effective date of this AD.
    (iii) For airplanes with 5,000 through 7,499 hours TIS, inspect 
within the next 6 months after the effective date of this AD.
    (iv) For airplanes with less than 5,000 hours TIS, inspect when 
the airplane accumulates a total of 5,000 hours TIS or within the 
next 12 months after the effective date of this AD, whichever occurs 
later.

(h) Repair

    If any damage, cracks, and/or cracks that exceed the allowable 
limits specified in the service bulletin are found during the 
inspection required in paragraph (g)(1) of this AD, before further 
flight, repair or replace parts as necessary following Twin 
Commander Aircraft LLC Service Bulletin 241, dated, September 26, 
2012. If Twin Commander Aircraft LLC Service Bulletin 241, dated, 
September 26, 2012, does not give procedures for repair of the 
damaged area, before further flight, you must contact Twin Commander 
Aircraft LLC to obtain repair instructions approved by the Seattle 
Aircraft Certification Office (ACO) specifically for compliance with 
this AD and incorporate those instructions. You can find contact 
information for Twin Commander Aircraft LLC in paragraph (l)(2) of 
this AD.

(i) Modification and Reassembly

    (1) Before further flight after completing the actions in 
paragraphs (g) and (h) of this AD, modify and reassemble the 
airplane using the modification and reassembly procedures in Part II 
of Twin Commander Aircraft LLC Service Bulletin 241, dated, 
September 26, 2012.
    (2) Although Twin Commander Aircraft LLC Service Bulletin 241, 
dated September 26, 2012, states that at least one person on the 
modification team must have completed the Twin Commander Aircraft 
LLC approved training, the FAA does not require that a mechanic 
complete this specialized training to do the modification work 
required in this AD. Regulations 14 CFR 65.81(a) and 14 CFR 65.81(b) 
provide criteria about qualifications of those performing 
maintenance; in this case, the requirements of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) 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. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    For more information about this AD, contact Vince Massey, 
Aerospace Engineer, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, 
WA 98057; telephone: (425) 917-6475; fax: (425) 917-6590; email: 
vince.massey@faa.gov.

(l) Material Incorporated by Reference

    (1) You must use the following service information to do the 
actions required by this AD, unless the AD specifies otherwise. The 
Director of the Federal Register approved the incorporation by 
reference (IBR) under 5 U.S.C. 552(a) and 1 CFR part 51:
    (i) Twin Commander Aircraft LLC Service Bulletin 241, dated 
September 26, 2012.
    (ii) Reserved.
    (2) For service information identified in this AD, contact Twin 
Commander Aircraft LLC; 1176 Telecom Drive, Creedmoor, NC 27522; 
telephone: (360) 403-0258; email: gpence@twincommander.com; 
Internet: http://www.twincommander.com.
    (3) You may review copies of the service information at the FAA, 
Small Airplane Directorate, 901 Locust, Kansas City, Missouri 64106. 
For information on the availability of this material at the FAA, 
call (816) 329-4148.
    (4) You may also review copies of the service information that 
is incorporated by reference 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/cfr/ibr_locations.html.

    Issued in Kansas City, Missouri, on April 25, 2013.
Earl Lawrence,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2013-10498 Filed 5-13-13; 8:45 am]
BILLING CODE 4910-13-P


