[Federal Register Volume 68, Number 47 (Tuesday, March 11, 2003)]
[Proposed Rules]
[Pages 11479-11481]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-5691]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-03-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc RB211 Trent 800 Series 
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) RB211 Trent 875, Trent 877, Trent 884, Trent 892, Trent 892B, and 
Trent 895 turbofan engines with high pressure (HP) compressor rotor 
rear stage 5 and 6 discs and cone shafts, part numbers (P/Ns) FK25230 
and FK27899 installed. This proposal would require removal from service 
of these HP compressor rotor rear stage 5 and 6 discs and cone shafts, 
before reaching newly reduced life limits. This proposal is prompted by 
three reports of crack indications in the stage 5 and stage 6 blade 
loading slots, found during engine overhaul. The actions specified by 
the proposed AD are intended to prevent crack initiation and 
propagation leading to uncontained disc failure and damage to the 
airplane.

DATES: Comments must be received by May 12, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2003-NE-03-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location, by appointment, between 8 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: ``[email protected]''. 
Comments sent via the Internet must contain the docket number in the 
subject line.

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:

[[Page 11480]]

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 2003-NE-03-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. 2003-NE-03-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom (U.K.), recently notified the FAA that 
an unsafe condition may exist on RR RB211 Trent 875, Trent 877, Trent 
884, Trent 892, Trent 892B, and Trent 895 turbofan engines. The CAA 
advises that three HP compressor rotor rear stage 5 and 6 discs and 
cone shafts, P/Ns FK25230 and FK27899, were found with crack 
indications in the stage 5 and 6 blade loading slots, during overhaul 
inspection. The manufacturer's analysis has not yet been able to 
identify the root cause of these cracks, or to fully explain the crack 
propagation rate. As a result of the analysis thus far, a new lower 
life limit of 7,500 cycles-since-new (CSN) has been assigned by the 
manufacturer to these HP compressor rotor rear stage 5 and 6 discs and 
cone shafts. This condition, if not corrected, could result in stage 5 
and 6 disc crack initiation and propagation leading to uncontained disc 
failure and damage to the airplane.

Bilateral Agreement Information

    These engine models are manufactured in the U.K. 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.

Proposed Requirements of This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other RR RB211 Trent 875, Trent 877, Trent 884, 
Trent 892, Trent 892B, and Trent 895 turbofan engines of the same type 
design that are used on airplanes registered in the United States, the 
proposed AD would require replacing HP compressor rotor rear stage 5 
and 6 discs and cone shafts, P/Ns FK25230 and FK27899, at or before 
reaching the new reduced life cycle limit of 7,500 CSN.

Interim Action

    These proposed actions are considered interim action and the FAA 
may take additional actions in the future.

Economic Analysis

    There are approximately 350 engines of the affected design in the 
worldwide fleet. The FAA estimates that 90 engines installed on 
airplanes of U.S. registry would be affected by this proposed AD. The 
FAA also estimates that the prorated cost of the life reduction per 
engine would be approximately $112,195. Based on these figures, the 
total cost of the proposed AD is estimated to be $10,097,550.

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. 2003-NE-03-AD.

    Applicability: This airworthiness directive (AD) is applicable 
to Rolls-Royce plc (RR) RB211 Trent 875, Trent 877, Trent 884, Trent 
892, Trent 892B, and Trent 895 turbofan engines with high pressure 
(HP) compressor rotor rear stage 5 and 6 discs and cone shafts, part 
numbers (P/Ns) FK25230 and FK27899 installed. These engines are 
installed on, but not limited to Boeing 777 airplanes.

    Note 1: This 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 (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by

[[Page 11481]]

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 stage 5 and 6 disc crack initiation and propagation 
leading to uncontained disc failure and damage to the airplane, do 
the following:
    (a) Remove HP compressor rotor rear stage 5 and 6 discs and cone 
shafts, from service at or before accumulating 7,500 cycles-since-
new (CSN).
    (b) After the effective date of this AD, do not install any HP 
compressor rotor rear stage 5 and 6 discs and cone shaft, listed in 
this AD, that exceed 7,500 CSN.

Alternative Methods of Compliance

    (c) 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

    (d) 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.

    Note 3: The subject of this AD is addressed in CAA airworthiness 
directive 002-08-2002, dated November 22, 2002.


    Issued in Burlington, Massachusetts, on March 5, 2003.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 03-5691 Filed 3-10-03; 8:45 am]
BILLING CODE 4910-13-P