DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-1174; Project Identifier MCAI-2019-00135-E;
Amendment 39-21594; AD 2021-12-07]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG
(Type Certificate Previously Held by Rolls-Royce Deutschland GmbH,
Formerly BMW Rolls-Royce GmbH) Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
for
certain Rolls-Royce Deutschland Ltd & Co KG (RRD) BR700-710A1-10,
BR700-710A2-20 and BR700-710C4-11 model turbofan engines. This AD was
prompted by an investigation by RRD, which revealed a quality escape
during the high-pressure turbine (HPT) stage 1 disk rim cooling air
hole manufacturing process. This AD requires removing affected HPT
disks from service prior to reaching specified compliance times or at
the next engine shop visit, whichever occurs first. The FAA is issuing
this AD to address the unsafe condition on these products.
DATES: This AD is effective August 12, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 12,
2021.
ADDRESSES: For service information identified in this AD, contact
Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11, Dahlewitz 15827,
Germany; phone: +49 33 7086 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-2020-1174.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-1174; 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: Wego Wang, Aviation Safety Engineer,
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone:
(781) 238-7134; fax: (781) 238-7199; email: wego.wang@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 BR700-
710A1-10, BR700-710A2-20 and BR700-710C4-11 model turbofan engines. The
NPRM published in the Federal Register on January 21, 2021 (86 FR
6271). The NPRM was prompted by an investigation by RRD, which revealed
a quality escape during the HPT stage 1 disk rim cooling air hole
manufacturing process. In the NPRM, the FAA proposed to require
removing affected HPT disks from service prior to reaching specified
compliance times or at the next engine shop visit, whichever occurs
first. The FAA is issuing this AD to address the unsafe condition on
these products.
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Community, has
issued EASA AD 2019-0299, dated December 10, 2019 (referred to after
this as ``the MCAI''), to address the unsafe condition on these
products. The MCAI states:
An occurrence was reported of an HPT stage 1 disc burst on an
industrial gas turbine engine. Subsequent investigation revealed a
quality escape during HPT stage 1 disc rim cooling air hole
manufacturing process. A review revealed that 28 HPT stage 1 discs
were subject to a similar quality escape, two of which have been
recovered and removed from service. The consequence of this
manufacturing error is that the affected parts can no longer safely
reach their Declared Safe Cyclic Life (DSCL).
This condition, if not corrected, may lead to failure of an
affected part, possibly resulting in release of high-energy debris,
with consequent damage to, and/or reduced control of, the aeroplane.
To address this potentially unsafe condition, RRD issued the NMSB,
providing instructions to remove the engine from service for in-shop
replacement of the affected part.
For the reasons described above, this [EASA] AD reduces the DSCL
for the affected parts, requires identification of the affected parts
and removal
from service of each affected engine for replacement of the affected
part. This [EASA] AD also prohibits (re)installation of affected
parts.
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-2020-1174.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from two commenters. The commenters were
the Air Line Pilots Association, International (ALPA) and an anonymous
commenter. ALPA supported the NPRM without change. The anonymous
commenter supported the NPRM but stated their opinion on the estimated
costs.
Request for Rolls-Royce To Share Replacement Part Cost
An anonymous commenter indicated that Rolls-Royce could share the
cost of new HPT disks since it was their manufacturing process that
caused the defects in the HPT disks.
The FAA does not determine who pays for the costs of an AD. The
Estimated Costs paragraph indicates that, according to the
manufacturer, all of the costs of this AD may be covered under a
manufacturer warranty, thereby reducing the cost impact on affected
operators.
Conclusion
The FAA reviewed the relevant data, considered the comments
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes, this
AD is adopted as proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Rolls-Royce Alert Non-Modification Service
Bulletin (NMSB) SB-BR700-72-A900659, Revision 1, dated November 5, 2019
(the NMSB). The Alert NMSB provides the part numbers and serial numbers
for affected HPT disks, the serial numbers for all engines with an
affected HPT disk installed, and instructions for replacement of the
affected HPT disk. 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 21 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
|
Replace HPT disk |
20 work-hours x $85 per hour
= $1,700 |
$550,000
|
$551,700
|
$11,585,700
|
The FAA has included all known costs
in its cost estimate.
According to the manufacturer, however, all of the costs of this AD may
be covered under warranty, thereby reducing the cost impact on affected
operators.
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.
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
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:
|