[Federal Register: December 2, 2002 (Volume 67, Number 231)]
[Proposed Rules]
[Page 71495-71497]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02de02-29]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NE-10-AD]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce plc Model RB211-22B
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The Federal Aviation Administration (FAA) proposes to adopt a
new airworthiness directive (AD) that is applicable to Rolls-Royce plc
(RR) model RB211-22B turbofan engines with intermediate pressure (IP)
compressor stage 6 to 7 rotor shaft assembly part number (P/N) UL37094
installed. This proposal would require removal from service of IP
compressor stage 6 to 7 rotor shaft assemblies P/N UL37094 before
reaching newly reduced life limits. This proposal is prompted by the
discovery of corrosion during inspection and analysis of IP compressor
stage 6 to 7 rotor shaft assemblies returned from the field. The
actions specified by the proposed AD are intended to prevent corrosion-
induced cracking of the IP compressor stage 6 to 7 rotor shaft
assembly, resulting in an uncontained engine failure and damage to the
airplane.
DATES: Comments must be received by January 31, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 2002-NE-10-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at
this location, by appointment, between 8:00 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. Comments may also be sent via
the Internet using the following address: ``9-ane-adcomment@faa.gov''.
Comments sent via the Internet must contain the docket number in the
subject line.
[[Page 71496]]
Information regarding this action may be examined, by appointment,
at the FAA, New England Region, Office of the Regional Counsel, 12 New
England Executive Park, Burlington, MA.
FOR FURTHER INFORMATION CONTACT: Keith Mead, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803-5299, telephone (781) 238-
7744; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this action may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2002-NE-10--AD.'' The postcard will be date stamped
and returned to the commenter.
Availability of NPRM's
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 2002-NE-10-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Discussion
The manufacturer has recently analyzed the conditions of some IP
compressor stage 6 to 7 rotor shaft assemblies, P/N 37094, that were
returned from the field, and has determined that rotor shafts of this
part number are unable to achieve currently published life limits. This
is due to the potential for corrosion-induced cracking to occur at
these published life limits. As a result of this analysis, new lower
life limits have been assigned to this P/N IP compressor stage 6 to 7
rotor shaft assembly. This condition, if not corrected, could result in
corrosion-induced cracking of the IP compressor stage 6 to 7 rotor
shaft assembly, resulting in an uncontained engine failure and damage
to the airplane.
Proposed Requirements of this AD
Since an unsafe condition has been identified that is likely to
exist or develop on other RR model RB211-22B turbofan engines of the
same type design that are used on airplanes registered in the United
States, the proposed AD would require removing from service IP
compressor stage 6 to 7 rotor shaft assemblies, P/N UL37094, before
reaching new reduced life limits. The life limits are established based
on whether or not the engine has incorporated service bulletin (SB) RR
SB 72-8700. That SB increases the engine thrust rating.
Economic Analysis
The FAA estimates that one engine installed on aircraft of U.S.
registry would be affected by this proposed AD. The FAA also estimates
that no additional labor cost will be incurred to remove the affected
part, which will be at time of engine shop visit. Required parts would
cost approximately $33,150 per engine, based on a part life reduction
estimate. Based on these figures, the total cost of the proposed AD to
U.S. operators is estimated to be $33,150.
Regulatory Analysis
This proposed rule does not have federalism implications, as
defined in Executive Order 13132, because it would 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.
Accordingly, the FAA has not consulted with state authorities prior to
publication of this proposed rule.
For the reasons discussed above, I certify that this proposed
regulation (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);
and (3) if promulgated, 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. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new
airworthiness directive:
Rolls-Royce plc: Docket No. 2002-NE-10-AD.
Applicability: This airworthiness directive (AD) is applicable
to Rolls-Royce (RR) model RB211-22B turbofan engines with
intermediate pressure (IP) compressor stage 6 to 7 rotor shaft
assembly part number (P/N) UL37094 installed. These engines are
installed on, but not limited to Lockheed Martin L1011 airplanes.
Note 1: This airworthiness directive (AD) applies to each engine
identified in the preceding applicability provision, regardless of
whether it has been modified, altered, or repaired in the area
subject to the requirements of this AD. For engines that have been
modified, altered, or repaired so that the performance of the
requirements of this AD is affected, the owner/operator must request
approval for an alternative method of compliance in accordance with
paragraph (d) of this AD. The request should include an assessment
of the effect of the modification, alteration, or repair on the
unsafe condition addressed by this AD; and, if the unsafe condition
has not been eliminated, the request should include specific
proposed actions to address it.
Compliance:
Compliance with this AD is required as indicated, unless already
done.
To prevent corrosion-induced cracking of the IP compressor stage
6 to 7 rotor shaft assembly, resulting in an uncontained engine
failure and damage to the airplane, do the following:
(a) For engines that have not incorporated RR service bulletin
(SB) 72-8700, remove IP compressor stage 6 to 7 rotor shaft
assemblies from service before accumulating 13,500 cycles-since-new
(CSN).
[[Page 71497]]
(b) For engines that have incorporated RR service bulletin (SB)
72-8700, remove IP compressor stage 6 to 7 rotor shaft assemblies
from service before accumulating 12,980 cycles-since-new (CSN).
(c) After the effective date of this AD, do not install any IP
compressor stage 6 to 7 rotor shaft assembly, P/N UL37094, that has
accumulated the CSN specified in paragraph (a) or (b) of this AD.
Alternative Methods of Compliance
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Engine Certification Office (ECO).
Operators must submit their request through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, ECO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the ECO.
Special Flight Permits
(e) Special flight permits may be issued in accordance with
Sec. Sec. 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be done.
Issued in Burlington, Massachusetts, on November 20, 2002.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 02-30350 Filed 11-29-02; 8:45 am]
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