[Federal Register Volume 65, Number 46 (Wednesday, March 8, 2000)]
[Rules and Regulations]
[Pages 12084-12085]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-4929]



[[Page 12084]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-59-AD; Amendment 39-11605; AD 2000-04-22]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc 524 Series and Trent 
768-60 and 772-60 Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Rolls-Royce plc (RR) RB211-524G2-T-19; RB211-524G3-T-
19; RB211-524H2-T-19; RB211 Trent 768-60; and RB211 Trent 772-60 
turbofan engines. This AD requires the replacement of the joint bolt 
assemblies that secure the high-pressure compressor (HPC) to the high-
pressure turbine (HPT) of the RB211-524 series and Trent 768 and 772 
series turbofan engines. This amendment is prompted by six incidents of 
bolt failure, one of which resulted in a damaged stage 6 HPC disk 
following an impact with a separated bolt head. The actions specified 
in this AD are intended to prevent failure of the HPC-to-HPT joint bolt 
assemblies, which could result in a cracked stage 6 HPC disk, possible 
uncontained engine failure, and damage to the airplane.

DATES: Effective April 7, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 7, 2000.
    Comments for inclusion in the Rules Docket must be received on or 
before May 8, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 99-NE-59-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ane-
[email protected].'' Comments sent via the Internet must contain the 
docket number in the subject line.
    The service information referenced in this AD may be obtained from 
Rolls-Royce plc, PO Box 31, Derby, England; telephone: International 
Access Code 011, Country Code 44, 1332-249428, fax: International 
Access Code 011, Country Code 44, 1332-249223. This information may be 
examined at the FAA, New England Region, Office of the Regional 
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: James Lawrence, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone 781-
238-7176, fax 781-238-7199.

SUPPLEMENTARY INFORMATION: The Civil Aviation Authority (CAA), which is 
the airworthiness authority for the United Kingdom (UK), recently 
notified the Federal Aviation Administration (FAA) that an unsafe 
condition may exist on Rolls-Royce plc (RR) RB211-524G2-T-19; RB211-
524G3-T-19; RB211-524H2-T-19; and RB211 Trent 768-60 and 772-60 
turbofan engines. The CAA advises that it has received six reports of 
failures of high-pressure compressor (HPC)-to-high-pressure turbine 
(HPT) joint bolt assemblies, part number (P/N) BLT5543. In one case, a 
bolt head separated from the rest of the bolt and was propelled toward 
the HPC stage 6 disk where it caused impact damage to the stage 6 disk. 
A crack could initiate from the damage and propagate to disk failure. 
The investigation by the CAA has revealed that material selection, INCO 
909, contributed to the failure of the HPC-to-HPT joint bolt 
assemblies, P/N BLT5543. This condition, if not corrected, could result 
in failure of the HPC-to-HPT joint bolt assemblies, which could result 
in a cracked stage 6 HPC disk, possible uncontained engine failure, and 
damage to the airplane.

Manufacturer's Service Information

    RR has issued mandatory service bulletin (SB) RB.211-72-C491, 
Revision 1, dated October 8, 1999, that specifies procedures for 
replacement of the INCO 909 HPC-to-HPT joint bolt assemblies, P/N 
BLT5543, with INCO 718 HPC-to-HPT joint bolt assemblies, P/N BLT5541, 
during the next normal overhaul when the module is sufficiently 
disassembled to allow access to the bolts, but no later than June 30, 
2000. The CAA classified this service bulletin as mandatory and issued 
AD 004-10-99, dated October 8, 1999, in order to assure the 
airworthiness of these RR engines in the UK.

Bilateral Airworthiness Agreement

    These engine models are manufactured in the UK and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the CAA has kept the FAA informed of 
the situation described above. The FAA has examined the findings of the 
CAA, reviewed all available information, and determined that AD action 
is necessary for products of this type design that are certificated for 
operation in the United States.

Required Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of the same type design registered in 
the United States, this AD requires replacement of the INCO 909 HPC-to-
HPT joint bolt assemblies, P/N BLT5543, with INCO 718 HPC-to-HPT joint 
bolt assemblies, P/N BLT5541, before further flight. The actions would 
be required to be accomplished in accordance with the SB described 
previously.

Difference of Compliance Times Between the Manufacturer's Service 
Bulletin and This AD

    RR SB No. RB.211-72-C491, Revision 1, dated October 8, 1999, 
requires that the joint bolts be replaced before June 30, 2000. The FAA 
has determined that since none of these engines are currently in use in 
the United States, the AD may require that the joint bolts be replaced 
before further flight.

Immediate Adoption

    Since there are currently no domestic operators of this engine 
model, notice and opportunity for prior public comment are 
impracticable. Therefore, a situation exists that allows the immediate 
adoption of this regulation.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and was not preceded by notice and 
an opportunity for public comment, comments are invited on this rule. 
Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that

[[Page 12085]]

supports the commenter's ideas and suggestions is extremely helpful in 
evaluating the effectiveness of the AD action and determining whether 
additional rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NE-59-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    The FAA has determined that this regulation is a nonsignificant 
regulation that may be issued immediately to correct an unsafe 
condition in engines, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this 
action involves a nonsignificant regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this regulation otherwise would be significant under 
DOT Regulatory Policies and Procedures, a final regulatory evaluation 
will be prepared and placed in the Rules Docket. A copy of it, if 
filed, 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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

2000-04-22  Rolls-Royce plc: Amendment 39-11605. Docket 99-NE-59-AD.

    Applicability: RB211-524G2-T-19; RB211-524G3-T-19; RB211-524H2-
T-19; and RB211 Trent 768-60 and 772-60 turbofan engines installed 
on, but not limited to Airbus Industrie A330 series and The Boeing 
Co. 747 series 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 (b) 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: Required as indicated, unless accomplished 
previously.
    To prevent failure of the HPC-to-HPT joint bolt assemblies, 
which could result in a cracked stage 6 HPC disk, possible 
uncontained engine failure, and damage to the airplane accomplish 
the following:

Replacement of HPC-to-HPT Joint Bolt Assemblies

    (a) Replace INCO 909 HPC-to-HPT joint bolt assemblies, part 
number BLT5543, with INCO 718 HPC-to-HPT joint bolt assemblies, P/N 
BLT5541, before further flight, in accordance with the section 3.A., 
Accomplishment Instructions, of Rolls-Royce Mandatory service 
bulletin (SB) RB.211-72-C491, Revision 1, dated October 8, 1999.

Alternate Methods of Compliance

    (b) 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 shall submit their requests 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

    (c) 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.

Incorporation by Reference

    (d) Perform the actions required by this AD in accordance with 
Rolls-Royce Mandatory SB RB.211-72-C491, Revision 1, dated October 
8, 1999. 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, PO 
Box 31, Derby, England; telephone: International Access Code 011, 
Country Code 44, 1332-249428, fax: International Access Code 011, 
Country Code 44, 1332-249223. Copies may be inspected at the FAA, 
New England Region, Office of the Regional 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.
    (e) This amendment becomes effective on April 7, 2000.


    Issued in Burlington, Massachusetts, on February 21, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-4929 Filed 3-7-00; 8:45 am]
BILLING CODE 4910-13-U