[Federal Register Volume 67, Number 221 (Friday, November 15, 2002)]
[Proposed Rules]
[Pages 69160-69161]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-28954]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NE-12-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc Model RB211 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 RB211-535E4-B-37 and RB211-535E4-B-75 turbofan engines. This 
proposal would require removal from service of certain high pressure 
(HP) turbine discs before they reach newly established life limits. 
This proposal is prompted by the manufacturer's inspections and 
analysis of HP turbine discs that have accumulated high cycles. The 
analysis reveals these discs to be sensitive to corrosion-induced 
cracking in the disc rim cooling hole area, which could result in 
uncontained HP disc failure. The actions specified by the proposed AD 
are intended to prevent corrosion-induced cracking of the HP turbine 
disc which could cause an uncontained HP turbine disc failure and 
damage to the airplane.

DATES: Comments must be received by January 14, 2002.

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

Discussion

    The manufacturer has inspected and analyzed some HP turbine discs 
that have accumulated high cycles that were installed in model RB211-
535E4-B-37 and RB211-535E4-B-75 turbofan engines. The inspection and 
analysis reveals these discs to be sensitive to corrosion and crack 
propagation in the disc rim cooling hole area, which could result in 
uncontained HP turbine disc failure. The manufacturer has determined 
that the affected HP turbine discs are unable to achieve the previously 
published life limit of 20,000 cycles-since-new (CSN), due to the 
potential for corrosion-induced cracking

[[Page 69161]]

to occur at or near that published life limit.

Proposed Requirements of This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other RR model RB211-535E4-B-37 and RB211-535E4-B-
75 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 HP turbine discs, P/N's UL27680, UL27681, UL39766, and 
UL39767 before reaching the new life limit of 15,000 CSN.

Economic Analysis

    There are approximately 400 RR model RB211-535E4-B-37 and RB211-
535E4-B-75 turbofan engines in the worldwide fleet containing the 
affected HP turbine discs, P/N's UL27680, UL27681, UL39766, and 
UL39767. The FAA estimates that 346 engines installed on airplanes of 
U.S. registry will be affected by this AD, that it will take 
approximately 112 work hours per engine to replace an affected disc, 
and that the average labor rate is $60 per work hour. The FAA estimates 
that the prorated cost of the life reduction per engine would be 
approximately $64,000. Based on these figures, the total cost of the AD 
to remove from service the HP turbine discs at the new life limit of 
15,000 CIS, rather than the former life limit of 20,000 CIS, is 
estimated to be $24,469,120.

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-12-AD.

    Applicability: This airworthiness directive (AD) is applicable 
to Rolls-Royce plc (RR) model RB211-535E4-B-37 and RB211-535E4-B-75 
turbofan engines with high pressure (HP) turbine disc, P/N UL27680, 
UL27681, UL39766, or UL39767 installed. These engines are installed 
on, but not limited to Boeing 757 and Tupolev Tu204 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 (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 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 HP 
turbine disc which could cause an uncontained HP turbine disc 
failure and damage to the airplane, do the following:
    (a) Remove HP turbine disc from service before accumulating 
15,000 cycles-since-new (CSN).
    (b) After the effective date of this AD, do not install any HP 
turbine disc listed in this AD that exceeds 15,000 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.

    Issued in Burlington, Massachusetts, on November 6, 2002.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 02-28954 Filed 11-14-02; 8:45 am]
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