[Federal Register Volume 60, Number 44 (Tuesday, March 7, 1995)]
[Rules and Regulations]
[Pages 12411-12413]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-4545]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 93-ANE-40; Amendment 39-9154; AD 95-04-02]
Airworthiness Directives; Rolls-Royce, plc RB211-524 Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Rolls-Royce, plc RB211-524 series turbofan
engines, that requires a one-time modification of the nozzle guide vane
(NGV) assembly to incorporate vane core reinforcement inserts which
would prevent release of the stage 2 NGV seal ring, rotor contact, and
severance of the rotor drive arm. This amendment is prompted by a
report of an uncontained stage 1 low pressure turbine failure. The
actions specified by this AD are intended to prevent release of the
stage 2 NGV seal ring, which could result in an uncontained engine
failure.
DATES: Effective May 8, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of May 8, 1995.
ADDRESSES: The service information referenced in this AD may be
obtained from Rolls-Royce, plc, P.O. Box 31, Derby, England DE2 8BJ;
telephone 44-332-242424, 44-332-249936. This information may be
examined at the Federal Aviation Administration (FAA), New England
Region, Office of the Assistant Chief Counsel, 12 New England Executive
Park, Burlington, MA; or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Eugene Triozzi, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (617)
238-7148, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Rolls-Royce, plc (R-R)
RB211-524 series turbofan engines was published in the Federal Register
on October 4, 1993 (58 FR 51585). That action proposed to require a
one-time modification of the nozzle guide vane (NGV) assembly to
incorporate vane core reinforcement inserts which would prevent release
of the stage 2 NGV seal ring, rotor contact, and severance of the rotor
drive arm in accordance with R-R Mandatory Service Bulletin (SB) No.
RB.211-72-9672, Revision 1, dated November 6, 1992.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
One commenter concurs with the rule as proposed.
One commenter states that the proposed rule should provide separate
compliance times for spare engines. The commenter further states that
the proposed rule notes that no U.S. registry engines would be
affected. The commenter has one affected spare engine, and states that
an acceptable [[Page 12412]] level of safety would be maintained
provided the spare engine is modified within 20 months of installation.
The FAA concurs in part. The FAA has revised the economic analysis of
this final rule to include the one domestic spare engine. However, the
FAA does not concur with the proposal to require modifying spare
engines within 20 months after installation on Lockheed L-1011
aircraft, or at the next shop visit. The FAA has determined that the
acceptable level of safety maintained by this AD is based on total
fleet compliance within a finite period after AD issuance. The
commenter's proposal to modify spare engines within 20 months after
installation or at the next shop visit could allow indefinite operation
of unmodified engines, if an engine were removed for use as a spare
engine and subsequently installed without undergoing a shop visit.
Therefore, the FAA concludes that the compliance timetable originally
provided in the NPRM is appropriate to maintain an acceptable level of
safety.
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the change described
previously. The FAA has determined that this change will neither
increase the economic burden on any operator nor increase the scope of
the AD.
There are approximately 300 R-R RB211-524 series turbofan engines
of the affected design in the worldwide fleet. The FAA estimates that 1
spare engine of U.S. registry will be affected by this AD, that it will
take approximately 37 work hours per engine to accomplish the required
actions, and that the average labor rate is $60 per work hour. Required
parts will cost approximately $2,420 per engine. Based on these
figures, the total cost impact of the AD on U.S. operators is estimated
to be $4,640.
The regulations adopted herein will not have substantial direct
effects 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. Therefore, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (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); 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. A final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air Transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
95-04-02 Rolls-Royce, plc: Amendment 39-9154. Docket 93-ANE-40.
Applicability: Rolls-Royce, plc (R-R) Models RB211-524B-02, -
524B-B-02, -524B3-02, -524B2-19, -524B2-B-19, -524C2-19, and -524C2-
B-19 turbofan engines, installed on but not limited to Boeing 747
series and Lockheed L-1011 series aircraft.
Compliance: Required as indicated, unless accomplished
previously.
To prevent release of the stage 2 nozzle guide vane (NGV) seal
ring, which could result in an uncontained engine failure,
accomplish the following:
(a) For engines installed on Boeing 747 series aircraft, modify
the NGV assembly in accordance with R-R Mandatory Service Bulletin
(SB) No. RB.211-72-9672, Revision 1, dated November 6, 1992, at the
next shop visit, but not later than 9 months after the effective
date of this airworthiness directive (AD), whichever occurs first.
(b) For engines installed on Lockheed L-1011 series aircraft,
modify the NGV assembly in accordance with R-R Mandatory SB No.
RB.211-72-9672, Revision 1, dated November 6, 1992, at the next shop
visit, but not later than 20 months after the effective date of this
AD, whichever occurs first.
(c) For the purpose of this AD, a shop visit is defined as an
engine removal where engine maintenance entails separation of pairs
of mating engine flanges or the removal of a disk, hub, or spool.
(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. The
request should be forwarded through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Engine Certification Office.
Note: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(e) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the aircraft to a location where
the requirements of this AD can be accomplished.
(f) The modification shall be done in accordance with the
following SB:
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Document No. Pages Revision Date
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R-R SB No. RB.211-72-9672....... 1-31 1 Nov. 6, 1992.
R-R SB Supplement............... 1-2 1 Nov. 6, 1992.
Total pages 33
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This incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from Rolls-Royce, plc, P.O. Box 31,
Derby, England DE2 8BJ; telephone 44-332-242424, fax 44-332-249936.
Copies may be inspected at the FAA, New England Region, Office of
the Assistant Chief Counsel, 12 New England Executive Park,
Burlington, MA; or at the Office of the Federal Register, 800 North
Capitol Street NW., suite 700, Washington, DC.
(g) This amendment becomes effective on May 8, 1995.
[[Page 12413]] Issued in Burlington, Massachusetts, on February
15, 1995.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 95-4545 Filed 3-6-95; 8:45 am]
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