Airworthiness Directives; Rolls-Royce plc Turbofan Engines

[Federal Register Volume 81, Number 69 (Monday, April 11, 2016)]
[Rules and Regulations]
[Pages 21233-21234]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-08092]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-4076; Directorate Identifier 2015-NE-30-AD; 
Amendment 39-18483; AD 2016-08-07]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Rolls-Royce plc (RR) RB211-22B and RB211-524 turbofan engines with low-
pressure turbine (LPT) support roller bearing, part number (P/N) 
LK30313 or P/N UL29651, installed. This AD requires removal of certain 
LPT support roller bearings installed in RR RB211-22B and RB211-524 
engines. This AD was prompted by a report of a breach of the turbine 
casing and release of engine debris through a hole in the engine 
nacelle. We are issuing this AD to prevent failure of the LPT support 
roller bearing, loss of radial position following LPT blade failure, 
uncontained part release, damage to the engine, and damage to the 
airplane.

DATES: This AD becomes effective May 16, 2016.

ADDRESSES: See the FOR FURTHER INFORMATION CONTACT section.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
4076; 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 mandatory continuing airworthiness information 
(MCAI), 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: Brian Kierstead, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 
District Avenue, Burlington, MA 01803; phone: 781-238-7772; fax: 781-
238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to the specified products. The 
NPRM was published in the Federal Register on December 9, 2015 (80 FR 
76402). The NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    An RB211-524G2-T engine experienced an in-service event that 
resulted in breach of a turbine casing and some release of core 
engine debris through a hole in the engine nacelle. The 
investigation of the event determined the primary cause to have been 
fracture and release of a Low Pressure (LP) turbine stage 2 blade. 
The blade release caused secondary damage to the LP turbine, 
producing significant out-of-balance forces. The event engine was 
fitted with an LP turbine support bearing where the roller retention 
cage is constructed from two halves that are riveted together. The 
LP turbine imbalance resulted in an overload of the LP turbine 
support bearing and caused separation of the riveted, two -piece 
roller retention cage. Radial location of the LP turbine shaft was 
lost, allowing further progression of the event that resulted in a 
breach of the IP turbine casing.

    You may obtain further information by examining the MCAI in the AD 
docket on the Internet at http://www.regulations.gov by searching for 
and locating Docket No. FAA-2015-4076.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received.

Support for the NPRM (80 FR 76402, December 9, 2015)

    Boeing concurred with the NPRM.

Request To Change Compliance

    Orbital ATK and Lockheed Martin requested that the compliance time 
be based on LPT blade cycles instead of calendar time. Orbital ATK 
cites correspondence with the U.S. Rolls-Royce representative who 
recommends a 15,000 cycles-since-new (CSN) duration for the LPT blade 
design life. Since there is no calendar time driving the unsafe 
condition, Orbital ATK believes this is a good mitigation factor for 
low utilization rate operators. Orbital ATK believes that routine 
borescope inspections of the LPT blades and removal of the engine prior 
to reaching an LPT blade limit of 15,000 CSN offers an equivalent level 
of safety.
    We partially agree. We agree that the failure mode of the bearing 
support is not a time-based dependency. However, a compliance time of 
24 months is specified to allow for a shop visit interval. We have 
determined that removal of the LPT support roller bearing addresses the 
unsafe condition. Operators with unique circumstances may apply for an 
alternative method of compliance using the procedures listed in this 
AD. We did not change this AD.

Request To Change Costs of Compliance

    Lockheed Martin requested an adjustment to the estimated costs of 
compliance. The costs to low utilization operators would be 
significantly increased by imposing an unscheduled shop visit and/or 
unscheduled engine removal. Another possible contributor for increased 
costs is the lack of an approved repair station within the United 
States.
    We partially agree. We disagree that no repair stations exist 
within the U.S. that may perform the work required by this AD. We agree 
that this AD may drive low utilization operators to the shop faster. 
Operators with unique circumstances may apply for an alternative method 
of compliance using the procedures listed in this AD. We did not change 
this AD.

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
this AD as proposed.

Costs of Compliance

    We estimate that this AD affects 9 engines installed on airplanes 
of U.S. registry. We also estimate it will take 0 hours to comply with 
this AD. Removing the LPT support roller bearing is required during a 
shop visit; therefore, no additional time is needed for removal. 
Required parts cost about $8,184 per engine. The average labor rate is 
$85 per hour. Based on these figures, we estimate the cost of this AD 
on U.S. operators to be $73,656.

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

[[Page 21234]]

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

    We 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 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),
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction, 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):

2016-08-07 Rolls-Royce plc: Amendment 39-18483; Docket No. FAA-2015-
4076; Directorate Identifier 2015-NE-30-AD.

(a) Effective Date

    This AD becomes effective May 16, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Rolls-Royce plc RB211-22B-02, RB211-22B (MOD 
72-8700), RB211-524B-02, RB211-524B-B-02, RB211-524B2-19, RB211-
524B2-B-19, RB211-524B3-02, RB211-524B4-02, RB211-524B4-D-02, RB211-
524C2-19, RB211-524C2-B-19, RB211-524D4-19, RB211-524D4-B-19, RB211-
524D4X-19, RB211-524D4X-B-19, RB211-524D4-39, RB211-524D4-B-39, 
RB211-524G2-19, RB211-524G3-19, RB211-524-G2-T-19, RB211-524G3-T-19, 
RB211-524H-36, RB211-524H2-19, RB211-524H-T-36, and RB211-524H2-T-19 
turbofan engines, all serial numbers, with low-pressure turbine 
(LPT) support roller bearing, part number (P/N) LK30313 or P/N 
UL29651, installed.

(d) Reason

    This AD was prompted by a report of a breach of the turbine 
casing and release of engine debris through a hole in the engine 
nacelle. We are issuing this AD to prevent failure of the LPT 
support roller bearing, loss of radial position following LPT blade 
failure, uncontained part release, damage to the engine, and damage 
to the airplane.

(e) Actions and Compliance

    Comply with this AD within the compliance times specified, 
unless already done. At the next shop visit or within 24 months 
after the effective date of this AD, whichever occurs first, remove 
from service LPT support roller bearing, P/N LK30313 or P/N UL29651, 
and replace with a part eligible for installation.

(f) Installation Prohibition

    After the effective date of this AD, do not install an LPT 
support roller bearing, P/N LK30313 or P/N UL29651, onto any engine.

(g) Definition

    For the purpose of this AD, a ``shop visit'' is defined as 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine flanges, except that the 
separation of engine flanges solely for the purposes of 
transportation without subsequent engine maintenance does not 
constitute an engine shop visit.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: [email protected].

(i) Related Information

    (1) For more information about this AD, contact Brian Kierstead, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7772; fax: 781-238-7199; email: 
[email protected].
    (2) Refer to MCAI European Aviation Safety Agency AD 2015-0187, 
dated September 9, 2015, for more information. You may examine the 
MCAI in the AD docket on the Internet at http://www.regulations.gov 
by searching for and locating it in Docket No. FAA-2015-4076.

(j) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on April 4, 2016.
Colleen M. D'Alessandro,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.


[FR Doc. 2016-08092 Filed 4-8-16; 8:45 am]
BILLING CODE 4910-13-P

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T02:28:38.167483+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

f67ad6714fa3d9a53246dd14fa6be6a0fb64a1a70513315d832f80a45b5678f6

Text SHA-256

e5026a2b5ced1d63fc178e8f48a22d9bdd8de62d5c2d0fa47a0411c99801da41