Airworthiness Directives; Pratt & Whitney Canada Turboprop Engines

[Federal Register Volume 76, Number 239 (Tuesday, December 13, 2011)]
[Rules and Regulations]
[Pages 77380-77382]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-31868]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1298; Directorate Identifier 2011-NE-39-AD; 
Amendment 39-16888; AD 2011-25-12]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Canada 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 AD requires the removal of certain affected 
part manufacturer approval (PMA) replacement Timken Alcor Aerospace 
Technologies, Inc. (TAATI) first stage reduction sun gears and/or the 
interacting planetary gear sets from the propeller reduction gearbox 
assembly. This AD was prompted by a failure report of a certain TAATI 
PMA sun gear, installed since December 22, 2008. We are issuing this AD 
to prevent failure of the sun gear, which will result in an engine in-
flight shut down, possible uncontained engine failure, aircraft damage, 
and serious injuries.

DATES: This AD is effective December 28, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of December 28, 
2011.
    We must receive any comments on this AD by January 27, 2012.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: (202) 493-2251.
    <bullet> 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.
    <bullet> 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 Timken Alcor 
Aerospace Technologies, Inc., 3110 N. Oakland, Mesa, Arizona 85215; 
phone: (480) 632-1039; Web site: http://www.timken.com/mro. You may 
review copies of the referenced service information at the FAA, Engine 
& Propeller Directorate, 12 New England Executive Park, Burlington, MA. 
For information on the availability of this material at the FAA, call 
(781) 238-7125.

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: 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; 
email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    On October 12, 2011, we issued AD 2011-20-51, Amendment 39-16843 
(76 FR 64001, October 17, 2011), for Pratt & Whitney Canada PT6A-15AG, 
-27, -28, -34, -34AG, -34B, and -36 series turboprop engines having a 
TAATI PMA replacement first stage reduction sun gear, part number (P/N) 
E3024765, installed.

Actions Since AD 2011-20-51 (76 FR 64001, October 17, 2011) Was Issued

    Since we issued AD 2011-20-51, we received a report of another 
failure of a sun gear not listed in that AD. Analysis has revealed that 
additional PMA replacement TAATI gears, installed since December 22, 
2008, have the same failure potential as the gears affected by that AD. 
The additional gears are identified as follows:
    <bullet> Replacement first stage reduction sun gears, P/N E3024765, 
serial numbers (S/Ns) PC5-051 through PC5-089, and S/Ns SG36-051 
through SG36-120, including the associated planetary gears in propeller 
reduction gearbox assembly.
    <bullet> Replacement planetary gear sets, P/N E3101455-02, S/Ns EE-
051 through EE-197, S/Ns EE-4051 through EE-4094, and S/N EE-4113, 
including the associated sun gear in the propeller reduction gearbox 
assembly.

FAA's Determination

    We are issuing this AD because we evaluated all the relevant 
information and determined that 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 sun gears and planetary 
gear sets described previously.

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 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 we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. 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-2011-1298 and directorate identifier 2011-NE-39-
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.

[[Page 77381]]

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 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, records 
identifying the gear S/N for each gearbox do not exist, so that it will 
take about 10 work-hours to inspect gears for affected S/Ns and then to 
reassemble the reduction gearbox. 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.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA 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. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2011-25-12 Pratt & Whitney Canada: Amendment 39-16888; Docket No. 
FAA-2011-1298; Directorate Identifier 2011-NE-39-AD.

(a) Effective Date

    This AD is effective December 28, 2011.

(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 the first 
stage reduction sun gear or planetary gear set replacement since 
December 22, 2008, and having a:
    (1) 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) PC5-051 
through PC5-089, or S/Ns SG36-051 through SG36-120, installed; or
    (2) TAATI PMA replacement planetary gear set, P/N E3101455-02, 
S/Ns EE-051 through EE-197, or S/Ns EE-4051 through EE-4094, or S/N 
EE-4113, installed.

(d) Unsafe Condition

    This AD was prompted by a failure report of a certain TAATI PMA 
sun gear, installed since December 22, 2008. We are issuing this AD 
to prevent failure 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) Chip Detector Inspections

    (1) Within 10 operating hours after the effective date of this 
AD:
    (i) Inspect the chip detector on the propeller reduction gearbox 
assembly for metal debris.
    (ii) Do the inspections in accordance with paragraph 1 of the 
Accomplishment Instructions of Timken Alcor Aerospace Technologies, 
Inc. Alert Service Bulletin No. T-804, Revision B, dated November 7, 
2011. If the amount of metal debris found exceeds the allowable 
limits then, before further flight, permanently remove from service 
the affected gears as specified in paragraph (g) of this AD.
    (2) Repeat the chip detector inspections within every 25 
additional operating hours thereafter, until the affected gears are 
removed from service.

(g) Gear Removals From Service

    Within 60 operating hours or 365 days after the effective date 
of this AD, whichever occurs first, permanently remove from service 
the PMA replacement TAATI first stage reduction sun gear and the 
interacting planetary gears, and the PMA replacement TAATI planetary 
gear sets and interacting gears, listed in paragraph (c) of this AD, 
from the propeller reduction gearbox assembly.

(h) Installation Prohibition

    (1) 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-
051 through PC5-089, or S/Ns SG36-051 through SG36-120, or the 
associated planetary gears in the propeller reduction gearbox 
assembly.
    (2) After the effective date of this AD, do not install on any 
airplane, any engine or power section module with a TAATI PMA 
planetary gear set, P/N E3101455-02, S/Ns EE-051 through EE-197, or 
S/Ns EE-4051 through EE-4094, or S/N EE-4113, or the associated 
first stage sun gear in the propeller reduction gearbox assembly.

(i) Gears Are Matched Sets

    The sun gear and planetary gear sets as-installed are considered 
to be matched sets. Therefore, the sun gear and planetary gear sets 
associated as mating parts with an affected gear in the propeller 
reduction gearbox assembly must also be permanently removed from 
service.

(j) 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.

(k) 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; email: [email protected].

(l) Material Incorporated by Reference

    You must use the following service information to do the chip 
detector

[[Page 77382]]

inspections required by this AD, unless the AD specifies otherwise. 
The Director of the Federal Register approved the incorporation by 
reference under 5 U.S.C. 552(a) and 1 CFR part 51 of the following 
service information on the date specified:
    (1) Timken Alcor Aerospace Technologies, Inc. Alert Service 
Bulletin No. T-804, Revision B, dated November 7, 2011, approved for 
IBR December 28, 2011.
    (2) For service information identified in this AD, contact 
Timken Alcor Aerospace Technologies, Inc., 3110 N. Oakland, Mesa, 
Arizona 85215; phone: (480) 632-1039; Web site: http://www.timken.com/mro.
    (3) You may review copies of the service information at the FAA, 
New England Region, 12 New England Executive Park, Burlington, MA. 
For information on the availability of this material at the FAA, 
call (781) 238-7125.
    (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 an NARA facility, call (202) 741-6030 or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on December 1, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-31868 Filed 12-12-11; 8:45 am]
BILLING CODE 4910-13-P

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