[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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