
[Federal Register Volume 76, Number 200 (Monday, October 17, 2011)]
[Rules and Regulations]
[Pages 64001-64003]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-26840]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1038; Directorate Identifier 2011-NE-31-AD; 
Amendment 39-16843; AD 2011-20-51]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Canada PT6A-15AG, -27, 
-28, -34, -34AG, -34B, and -36 Series Turboprop Engines

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 Pratt & 
Whitney Canada PT6A-15AG, -27, -28, -34, -34AG, -34B, and -36 series 
turboprop engines. This emergency AD was sent previously to all known 
U.S. owners and operators of these engines. This AD requires the 
removal of affected part manufacturer approval (PMA) replacement Timken 
Alcor Aerospace Technologies, Inc. (TAATI) first stage reduction sun 
gears and the interacting planet gears, from the propeller reduction 
gearbox assembly. This AD was prompted by failures of certain PMA 
replacement first stage reduction sun gears, manufactured by TAATI. We 
are issuing this AD to correct the unsafe condition on these products.

DATES: This AD is effective November 1, 2011 to all persons except 
those persons to whom it was made immediately

[[Page 64002]]

effective by Emergency AD 2011-20-51, issued on September 15, 2011, 
which contained the requirements of this amendment.
    We must receive comments on this AD by December 1, 2011.

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: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations Office 
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 Operations 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: Paul Craig, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, FAA, 3960 Paramount Blvd., Suite 
100, Lakewood, CA 90712; phone: 562-627-5252; fax: 562-627-5210; e-
mail: paul.craig@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    On September 15, 2011, we issued Emergency AD 2011-20-51, which 
requires the removal of affected PMA replacement TAATI first stage 
reduction sun gears and the interacting planet gears, from the 
propeller reduction gearbox assembly. This action was prompted by 
failures of certain replacement PMA first stage reduction sun gears, 
manufactured by TAATI. This condition, if not corrected, could result 
in failure of the shaft portion of the sun gear, which will result in 
an engine in-flight shut down, possible uncontained engine failure, 
aircraft damage, and serious injuries.

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 the removal of affected PMA replacement TAATI 
first stage reduction sun gear and the interacting planet gears, from 
the propeller reduction gearbox assembly, within 15 operating hours or 
15 days after the effective date of this AD, whichever occurs first.

FAA's 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 of 
the short compliance time required in this AD to remove any affected 
parts from service. 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-2011-1038 and 
Directorate Identifier 2011-NE-31-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 the inspection in this AD will affect about 5,000 
engines installed on airplanes of U.S. registry. We also estimate that 
disassembly of reduction gearboxes will affect about 50 engines, and 
the sun gear removal will affect about 40 engines. We also estimate 
that it will take about 1 work-hour per engine for inspecting the 
engine records. We also estimate that for about 10 engines, it will 
take about 10 work-hours for the inspection of the sun gear serial 
number (S/N) and reassembly of the reduction gearbox, due to the 
records not identifying the S/N. We also estimate that it would take 
about 16 work-hours for parts replacement. The average labor rate is 
$85 per work-hour. Required parts for one engine will cost about 
$14,500. Based on these figures, we estimate the cost of the AD on U.S. 
operators to be $1,067,900.

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

    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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

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

[[Page 64003]]

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):

2011-20-51 Pratt & Whitney Canada: Amendment 39-16843; Docket No. 
FAA-2011-1038; Directorate Identifier 2011-NE-31-AD.

(a) Effective Date

    This AD is effective November 1, 2011 to all persons except 
those persons to whom it was made immediately effective by Emergency 
AD 2011-20-51, issued on September 15, 2011, which contained the 
requirements of this amendment.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pratt & Whitney Canada PT6A-15AG, -27, -28, -
34, -34AG, -34B, and -36 series turboprop engines that have had 
maintenance done to the power section module involving first stage 
reduction sun gear replacement since February 3, 2010, and having a 
Timken Alcor Aerospace Technologies, Inc. (TAATI) part manufacturer 
approval (PMA) replacement first stage reduction sun gear, part 
number (P/N) E3024765, serial numbers (S/Ns) PC5-091 through PC5-
176, installed.

(d) Unsafe Condition

    This AD was prompted by failures of certain first stage 
reduction sun gears, manufactured by TAATI. We are issuing this AD 
to prevent failure of the shaft portion of the sun gear, which will 
result in an engine in-flight shut down, possible uncontained engine 
failure, aircraft damage, and serious injuries.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (f) For affected engines, remove the PMA replacement TAATI first 
stage reduction sun gear and the interacting planet gears from the 
propeller reduction gearbox assembly within 15 operating hours or 15 
days after the effective date of this AD, whichever occurs first.

(g) Installation Prohibition

    After the effective date of this AD, do not install on any 
airplane, any engine or power section module with a TAATI PMA 
replacement first stage reduction sun gear, P/N E3024765, S/Ns PC5-
091 through PC5-176.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Los Angeles Aircraft Certification Office, FAA, has 
the authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19.

(i) Related Information

    For further information about this AD, contact: Paul Craig, 
Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, 
3960 Paramount Blvd., Suite 100, Lakewood, CA 90712; phone: 562-627-
5252; fax: 562-627-5210; e-mail: paul.;craig@faa.gov.

    Issued in Burlington, Massachusetts, on October 12, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-26840 Filed 10-14-11; 8:45 am]
BILLING CODE 4910-13-P


