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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-0213; Project Identifier 2019-NE-03-AD; Amendment
39-21324; AD 2020-23-08]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG
(Type Certificate Previously Held by Rolls-Royce plc) Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD)
for
certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Tay 611-8C model
turbofan engines. This AD was prompted by reports of low-pressure
compressor (LPC) rotor blade retention lug failure. This AD requires
limiting the service life of the LPC rotor blades based on the number
of dry-film lubricant (DFL) re-applications. The FAA is issuing this AD
to address the unsafe condition on these products.
DATES: This AD is effective December 18, 2020.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of December 18,
2020.
ADDRESSES: For service information identified in this final rule,
contact Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11, Dahlewitz,
Blankenfelde-Mahlow, Germany; phone: +49 0 33-7086-4040; fax: +49 0 33-
7086-51-4040; email: rrd.techhelp@rolls.royce.com. You may view this
service information at the FAA, Airworthiness Products Section,
Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803.
For information on the availability of this material at the FAA, call
(781) 238-7759. It is also available at https://www.regulations.gov by
searching for and locating Docket No.FAA-2019-0213.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2019-0213; or in person at
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket contains this final rule, the
mandatory continuing airworthiness information (MCAI), any comments
received, and other information. The address for Docket Operations is
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: Barbara Caufield, Aviation Safety
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
phone: (781) 238-7146; fax: (781) 238-7199; email:
barbara.caufield@faa.gov.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain RRD Tay 611-8C
model turbofan engines. The NPRM published in the Federal Register on
May 6, 2019 (84 FR 19745). The NPRM was prompted by reports of LPC
rotor blade retention lug failures. In the NPRM, the FAA proposed to
require a determination of the number of DFL re-applications that have
been applied to the LPC rotor blades and, depending on the number of
DFL re-applications, replacement of LPC rotor blades. The FAA is
issuing this AD to address the unsafe condition on these products.
The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued EASA
AD 2018-0055, dated March 12, 2018 (referred to after this as ``the
MCAI''), to address the unsafe condition on these products. The MCAI
states:
The airworthiness limitations for the Tay 611-8C engines, which
are approved by EASA, are currently defined and published in the
ALS. Among others, the ALS contains limitation(s) applicable to the
maximum number of Dry Film Lubrication (DFL) treatments applied on
fan blade retention lugs. These instructions have been identified as
mandatory for continued airworthiness. Failure to accomplish these
instructions could result in an unsafe condition.
In addition to the ALS, RRD issued the NMSB to provide
alternative methods to establish, in case this cannot be determined
from the engine maintenance records, the number of DFL treatments
that have been applied to an engine.
You may obtain further information by examining the MCAI in the AD
docket at https://www.regulations.gov by searching for and locating
Docket No. FAA-2019-0213.
Comments
The FAA gave the public the opportunity to participate in
developing this final rule. The following presents the comments
received on the NPRM and the FAA's response to each comment.
Request To Modify Applicability
NetJets Aviation (NJA) requested that engines which have
incorporated the 12,000 cycle life limit on LPC rotor blade, part
number JR58319, per the Airworthiness Limitations section 05-10-01-870-
002, chapter 05-10-01, Rolls-Royce (RR) Tay Propulsion System Time
Limits Manual, be excluded from the applicability of this AD.
The FAA disagrees because the low cycle fatigue life limit of
12,000 cycles for the LPC rotor blade is a separate requirement from
the requirement of this AD to also limit the number of dry film
lubricant re-applications.
Comment Regarding DFL Re-application Limit
NJA noted that dry film re-application is only accomplished in an
engine overhaul shop, and the 12 DFL-application limit every 1,300
cycles will not be exceeded if the life limit is being tracked. The FAA
disagrees. The FAA notes that there are tasks in the Aircraft
Maintenance Manual (AMM) for DFL re-applications that are not limited
to shop visits. Therefore, this AD is necessary to address those cases
in which the AMM DFL re-application tasks are necessary and the engine
is not in the shop. This AD requires that when a complete
record of the total number of DFL re-applications is unavailable, count
one DFL re-application for every 1,300 flight cycles of blade use.
Request to Add Engine Serial Numbers
NJA requested that the serial numbers for the 12 affected engines
be included in this AD.
The FAA disagrees. The applicability of this AD is to RRD Tay 611-
8C model turbofan engines, with LPC rotor blades, P/N JR58319,
installed, and is not based on serial numbers of the engines. The
number ``12'' in the Costs of Compliance section is an estimate of the
number of affected engines installed on airplanes of U.S. registry.
Conclusion
The FAA reviewed the relevant data, considered the comments
received, and determined that air safety and the public interest
require adopting this final rule as proposed except for minor editorial
changes. The FAA has determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
Related Service Information under 1 CFR Part 51
The FAA reviewed RRD Non-Modification Service Bulletin TAY-72-1835,
Initial Issue, dated December 15, 2017. The service information
describes procedures for marking the LPC rotor blades with a suffix
code during the next scheduled LPC fan blade removal. This service
information is reasonably available because the interested parties have
access to it through their normal course of business or by the means
identified in ADDRESSES.
Costs of Compliance
The FAA estimates that this AD affects 12 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
Estimated costs
|
Action
|
Labor cost
|
Parts cost
|
Cost per
product
|
Cost on
U.S. operators
|
| Record Search to establish number
of DFL re-applications |
1.5 work-hours x $85 per
hour = $127.50 |
$0
|
$127.50
|
$1,530
|
The FAA estimates the following costs
to do any necessary
replacements that would be required based on the results of the
inspection. The agency has no way of determining the number of aircraft
that might need these replacements.
On-condition costs
|
Action
|
Labor cost
|
Parts cost
|
Cost per
product
|
| Replace LPC rotor blade |
2 work-hours x $85 per hour =
$170 |
$11,270
|
$11,440
|
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.
The FAA is 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 this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Will not affect intrastate aviation in Alaska, and
(3) 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.
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
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]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
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