Airworthiness Directives; Rolls-Royce Corporation Turboshaft Engines

[Federal Register Volume 77, Number 132 (Tuesday, July 10, 2012)]
[Rules and Regulations]
[Pages 40479-40481]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-16797]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0961; Directorate Identifier 2011-NE-22-AD; 
Amendment 39-17120; AD 2012-14-06]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation Turboshaft 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Rolls-Royce Corporation (RRC) 250-C20, -C20B, and -C20R/2 turboshaft 
engines. This AD was prompted by seven cases reported of released 
turbine blades and shrouds, which led to loss of power and engine in-
flight shutdowns (IFSDs). This AD requires a one-time visual inspection 
and fluorescent penetrant inspection (FPI) on certain 3rd and 4th stage 
turbine wheels for cracks in the turbine blades. We are issuing this AD 
to prevent failure of 3rd or 4th stage turbine wheel blades which could 
cause engine failure and damage to the airplane.

DATES: This AD is effective August 14, 2012.

ADDRESSES: For service information identified in this AD, contact 
Rolls-Royce Corporation Customer Support, P.O. Box 420, Indianapolis, 
IN 46206-0420; phone: 888-255-4766 or 317-230-2720; fax: 317-230-3381, 
email: royce.com">helicoptercustsupp@rolls-royce.com, and Web site: www.rolls-
royce.com. 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

[[Page 40480]]

docket contains this AD, the regulatory evaluation, any comments 
received, and other information. The address for the Docket Office 
(phone: 800-647-5527) is Document Management Facility, U.S. Department 
of Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: John Tallarovic, Aerospace Engineer, 
Chicago Aircraft Certification Office, FAA, 2300 E. Devon Ave., Des 
Plaines, IL 60018; phone: 847-294-8180; fax: 847-294-7834; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on December 20, 2011 (76 FR 
78863). That NPRM proposed to require a one-time visual inspection and 
FPI on certain 3rd and 4th stage turbine wheels for cracks in the 
turbine blades.

Comments

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

Proposed AD Applicability Clarity

    One commenter said that the proposed AD applicability is unclear. 
The commenter stated that the RRC Commercial Engine Bulletins (CEBs) 
referenced in the proposed AD apply to specific model 250 engines in MD 
Helicopter, Inc. aircraft only. However, the proposed AD appears to 
cover the subject part number (P/N) wheels in three engine models in 
all applications. Also, the subject P/N wheels can be installed in many 
engine models in addition to the 250-C20, C20B, and C20R/2 engines 
called out in the proposed AD. The original issue with the wheels 
cracking was tied to specific power turbine speed ranges as manifested 
in specific aircraft applications. As the proposed AD is written, there 
are airframe applications where one model of installed engine would be 
subject to the AD and another model being only slightly different and 
identical in the power turbine section concerned, would not be subject 
to the AD.
    We do not agree. The proposed AD is only applicable to the model 
250-C20, C20B, and C20R/2 turboshaft engines on all installations. The 
affected turbine wheels, P/N 23065818 and P/N 23055944, can be 
installed on other model 250 engines. However, the proposed AD is only 
applicable to the model 250-C20, C20B, and C20R/2 turboshaft engines. 
While RRC Alert CEB-A-1407, Revision 1, dated February 7, 2011 and CEB-
A-72-4098, Revision 1, dated February 7, 2011 (combined in one 
document) is directed at engines installed on MD Helicopters Inc. 
aircraft, the proposed AD is applicable to all installations of model 
250-C20, C20B, and C20R/2 turboshaft engines. The service bulletins do 
not establish the applicability for the proposed AD. The service 
bulletins are referenced as related information only. We did not change 
the AD.

Overhaul Period

    One commenter pointed out that paragraph (e)(1) of the proposed AD 
stated to remove the turbine wheels at the next 1,750 hour overhaul. 
The overhaul period in these engines is 3,500 hours, not 1,750 hours.
    We agree. We changed paragraph (e)(1) to state to remove the 3rd 
stage turbine wheel, P/N 23065818, and the 4th stage turbine wheel, P/N 
23055944, before accumulating 1,750-hours since last inspection.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the change described previously.

Costs of Compliance

    We estimate that this AD will affect 500 RRC C250-C20, -C20B, and -
C20R/2 turboshaft engines installed on aircraft of U.S. registry. We 
also estimate that it will take about 5 hours to perform a one-time 
visual inspection and FPI of the 3rd stage turbine wheel and the 4th 
stage turbine wheel for each engine. The average labor rate is $85 per 
work-hour. Based on these figures, we estimate the total cost of the AD 
to U.S. operators to be $212,500.

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 
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 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):

2012-14-06 Rolls-Royce Corporation (Formerly Allison Engine Company 
and Allison Gas Turbine Division of General Motors): Amendment 39-
17120; Docket No. FAA-2011-0961; Directorate Identifier 2011-NE-22-
AD.

(a) Effective Date

    This AD is effective August 14, 2012.

(b) Affected ADs

    None.

[[Page 40481]]

(c) Applicability

    This AD applies only to Rolls-Royce Corporation 250-C20, -C20B, 
and -C20R/2 turboshaft engines with 3rd stage turbine wheel, part 
number (P/N) 23065818, and 4th stage turbine wheel, P/N 23055944.

(d) Unsafe Condition

    This AD was prompted by seven cases reported of released turbine 
blades and shrouds, which led to loss of power and engine in-flight 
shutdowns. We are issuing this AD to prevent failure of 3rd or 4th 
stage turbine wheel blades which could cause engine failure and 
damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Remove the 3rd stage turbine wheel, P/N 23065818, and the 
4th stage turbine wheel, P/N 23055944, within 1,750-hours since last 
inspection.
    (2) Perform a one-time visual inspection and a fluorescent 
penetrant inspection on the 3rd and 4th stage turbine wheels for 
cracks at the trailing edge of the turbine blades near the fillet at 
the rim.
    (3) If any cracks in the trailing edge near the rim are 
detected, do not return the wheel to service.

(f) Alternative Methods of Compliance (AMOCs)

    The Manager, Chicago Aircraft Certification Office, FAA, may 
approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 
to make your request.

(g) Related Information

    (1) For more information about this AD, contact John Tallarovic, 
Aerospace Engineer, Chicago Aircraft Certification Office, FAA, 2300 
E. Devon Ave., Des Plaines, IL 60018; phone: 847-294-8180; fax: 847-
294-7834; email: [email protected].
    (2) Rolls-Royce Corporation Alert Commercial Engine Bulletin No. 
CEB-A-1407, Revision 1, dated February 7, 2011 and CEB-A-72-4098, 
Revision 1, dated February 7, 2011 (combined in one document) 
pertain to the subject of this AD.
    (3) For service information identified in this AD, contact 
Rolls-Royce Corporation Customer Support, P.O. Box 420, 
Indianapolis, IN 46206-0420; phone: 888-255-4766 or 317-230-2720; 
fax: 317-230-3381; email: royce.com">helicoptercustsupp@rolls-royce.com, and 
Web site: www.rolls-royce.com.
    (4) You may review copies of the referenced service information 
at the FAA, Engine & Propeller Directorate, 12 New England Executive 
Park, Burlington, MA 01803. For information on the availability of 
this material at the FAA, call 781-238-7125.

    Issued in Burlington, Massachusetts, on June 25, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-16797 Filed 7-9-12; 8:45 am]
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