[Federal Register Volume 66, Number 233 (Tuesday, December 4, 2001)]
[Proposed Rules]
[Pages 63009-63012]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-29949]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NE-36-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc. Tay Model 650-15 and 
651-54 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. 
Tay Model 650-15 and 651-54 turbofan engines. This proposal would 
require revisions to the Airworthiness Limitations Section (ALS) of the 
Instructions for Continued Airworthiness (ICA) in the Time Limits 
Section of the Engine Manual for Rolls-Royce plc. Tay model 650-15 and 
651-54 series turbofan engines to include required enhanced inspection 
of selected critical life-limited parts at each piece-part exposure. An 
FAA study of in-service events involving uncontained failures of 
critical rotating engine parts has indicated the need for mandatory 
inspections. The mandatory inspections are needed to identify those 
critical rotating parts with conditions, which if allowed to continue 
in service, could result in uncontained failures. The actions specified 
by this proposed AD are intended to prevent critical life-limited 
rotating engine part failure, which could result in an uncontained 
engine failure and damage to the airplane.

DATES: Comments must be received by February 4, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No.2001-NE-36-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: 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

[[Page 63010]]

Docket Number 2001-NE-36-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. 2001-NE-36-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    A recent FAA study analyzing 15 years of accident data for 
transport category airplanes identified several failure mode root 
causes that can result in serious safety hazards to transport category 
airplanes. This study identified uncontained failure of critical life-
limited rotating engine parts as the leading engine-related safety 
hazard to airplanes. Uncontained engine failures have resulted from 
undetected cracks in rotating parts that initiated and propagated to 
failure. Cracks can originate from causes such as unintended excessive 
stress from the original design, or they may initiate from stresses 
induced from material flaws, handling, or damage from machining 
operations. The failure of rotating parts can present a significant 
safety hazard to the airplanes by release of high energy fragments that 
could injure passengers or crew by penetration of the cabin, damage 
flight control surfaces, sever flammable fluid lines, or otherwise 
compromise the airworthiness of the airplane.
    Accordingly, the certifying authority responsible for the state of 
design for these engines, with FAA concurrence, has developed an 
intervention strategy to significantly reduce uncontained engine 
failures. This intervention strategy was developed after consultation 
with industry and will be used as a model for future initiatives. This 
intervention strategy is to conduct enhanced, nondestructive 
inspections of rotating parts which could most likely result in a 
safety hazard to the airplane in the event of a part fracture. The need 
for additional rule making is also being considered by the FAA. Future 
ADs may be issued introducing additional intervention strategies to 
further reduce or eliminate uncontained engine failures.
    Properly focused enhanced inspections require identification of the 
parts whose failure presents the highest safety hazard to the airplane, 
identifying the most critical features to inspect on these parts, and 
utilizing inspection procedures and techniques that improve crack 
detection. The certifying authority, with close cooperation of the 
engine manufacturer, has completed a detailed analysis that identifies 
the most safety significant parts and features, and the most 
appropriate inspection methods.
    Critical life-limited high energy rotating parts are currently 
subject to some form of recommended crack inspection when exposed 
during engine maintenance or disassembly. As a result of this AD, the 
inspections currently recommended by the manufacturer will become 
mandatory for those parts listed in the compliance section. 
Furthermore, the FAA intends that additional mandatory enhanced 
inspections resulting from this AD serve as an adjunct to the existing 
inspections. The FAA has determined that the enhanced inspections will 
significantly improve the probability of crack detection while the 
parts are disassembled during maintenance. All mandatory inspections 
must be conducted in accordance with detailed inspection procedures 
prescribed in the manufacturer's Engine Manual.
    Additionally, this AD allows for air carriers operating under the 
provisions of 14 CFR part 121 with an FAA-approved continuous 
airworthiness maintenance program, and entities with whom those air 
carriers make arrangements to perform this maintenance, to verify 
performance of the enhanced inspections by retaining the maintenance 
records that include the inspections resulting from this AD, provided 
that the records include the date and signature of the person 
performing the maintenance action. These records must be retained with 
the maintenance records of the part, engine module, or engine until the 
task is repeated. This will establish a method of record preservation 
and retrieval typical to those in existing continuous airworthiness 
maintenance programs. Instructions must be included in an air carrier's 
maintenance manual providing procedures on how this record preservation 
and retrieval system will be implemented and integrated into the air 
carrier's record keeping system.
    For engines or engine modules that are approved for return to 
service by an authorized FAA-certificated entity and that are acquired 
by an operator after the effective date of this AD, the mandatory 
enhanced inspections need not be done until the next piece-part 
opportunity. For example, there is no need for an operator to 
disassemble to piece-part level an engine or module returned to service 
by an FAA-certificated facility simply because that engine or module 
was previously operated by an entity not required to comply with this 
AD. Furthermore, the FAA intends for operators to perform the enhanced 
inspections of these parts at the next piece-part opportunity following 
the initial acquisition, installation, and removal of the part 
following the effective date of this AD. For piece parts that have not 
been approved for return to service prior to the effective date of this 
AD, the FAA does intend that the mandatory enhanced inspections 
required by this AD be performed before such parts are approved for 
return to service. Piece parts that have been approved for return to 
service prior to the effective date of this AD may be installed; 
however, enhanced inspection will be required at the next piece-part 
opportunity.
    This proposal would require, within the next 30 days after the 
effective date of this AD, revisions to the Airworthiness Limitations 
Section (ALS) and Maintenance Scheduling Section (MSS) of the 
Instructions for Continued Airworthiness (ICA) (chapter 05-20-01-800-
001) of the Engine Manuals, as follows:
    Rolls Royce plc. Tay model 650-15, and 651-54 series turbofan 
engines, respectively, and, for air carriers, the approved continuous 
airworthiness maintenance program. Rolls Royce plc., the manufacturer 
of Rolls Royce plc. Tay model 650-15, and 651-54 turbofan engines, used 
on 14 CFR part 25 airplanes, has provided the certifying authority, 
responsible for the state of design of these aircraft engines with a 
detailed proposal, with FAA concurrence, that identifies and 
prioritizes the critical life-limited rotating engine parts with the 
highest potential to hazard the airplane in the event of failure, along 
with instructions for enhanced, focused inspection methods. The 
enhanced inspections resulting from this AD will be conducted at piece-
part opportunity, as defined below in the compliance section, rather 
than at specific time inspection intervals.

Proposed Requirements of This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Rolls-Royce plc. Tay Model 650-15 and 651-54 
turbofan engines of the same type design that are used on Boeing 727 
and Fokker 100 airplanes registered in the United States, the proposed 
AD would require revisions to the Airworthiness Limitations Section 
(ALS) of the Instructions for Continued Airworthiness (ICA) in the Time 
Limits Manual of the Engine Manual for Rolls-Royce plc. Tay model 650-
15, and 651-54 series turbofan engines to include

[[Page 63011]]

required enhanced inspection of selected critical life-limited parts at 
each piece-part exposure.

Economic Analysis

    There are approximately 700 engines of the affected design in the 
worldwide fleet. The FAA estimates that 448 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD. The 
FAA also estimates that it would take approximately twenty work hours 
per engine to accomplish the proposed inspections , and that the 
average labor rate is $60 per work hour. Since this is an added 
inspection requirement, included as part of the normal maintenance 
cycle, no additional part costs are involved. Based on these figures, 
the total cost impact of the proposed AD on U.S. operators is estimated 
to be $537,600.

Regulatory Impact

    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. 2001-NE-36-AD:

Applicability

    This airworthiness directive (AD) is applicable to Rolls-Royce 
plc. Tay Model 650-15 and 651-54 turbofan engines. These engines are 
installed on, but not limited to Boeing 727 and Fokker 100 
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 critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to 
the airplane, accomplish the following:
    (a) Within the next 30 days after the effective date of this AD, 
revise the Airworthiness Limitations Section (ALS) and Maintenance 
Scheduling Section (MSS) of the Instructions for Continued 
Airworthiness (ICA) in the Time Limits Manuals publication number 
(P/N) T-TAY-3RR, and T-TAY-5RR of the Engine Manuals, P/N E-TAY-3RR, 
and E-TAY-5RR as applicable, and for air carrier operations revise 
the approved continuous airworthiness maintenance program, by adding 
the following: ``GROUP A PARTS MANDATORY INSPECTION TASK 05-20-01-
800-001
    (1) General: A full inspection of Group A Parts must be effected 
whenever the following conditions are satisfied.
    (i) When the component has been completely disassembled to 
piece-part level in accordance with the appropriate disassembly 
procedures contained in the Engine Manual.
      and
    (ii) The part has accumulated in excess of 100 flight cycles in 
service or since the last piece-part inspection.
      or
    (iii) The component removal was for damage or a cause directly 
related to its removal.
    (2) Mandatory inspections for individual Group A Parts are 
specified below: For time limits manual T-211(524)-7RR (reference 
engine manual M-211(524)-7RR) only, insert the following Table:

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                                                                                        Inspected per overhaul
               Part nomenclature                              Part No.                       manual task
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Low Pressure Compressor Rotor Disc............  All................................           72-31-11-200-000
I. P. Compressor Rotor--Stage 1 Disc..........  All................................          72-33-31-200--000
I. P. Compressor Rotor--Stage 2 Disc..........  All................................           72-33-32-200-000
I. P. Compressor Rotor--Stage 3 Disk..........  All................................           72-33-33-200-000
L. P. and I. P. Compressor Drive Shaft........  All................................           72-33-40-200-000
H. P. Compressor Rear Drive Shaft.............  All................................           72-37-31-200-000
L. P. Compressor Rotor Drive Shaft............  All................................           72-37-32-200-002
H. P. Compressor Stage 1 Rotor Disc...........  All................................           72-37-33-200-001
H. P. compressor Stages 2 and 3 Rotor Discs...  All................................           72-37-33-200-002
H. P. Compressor Stages 4, 5, 6, and 7 Rotor    All................................           72-37-34-200-000
 Discs.
H. P. Compressor Stages 8, 9, 10, and 11 Rotor  All................................      72-37-35-200-000/-001
 Discs.
H. P. Stage 12 Rotor Disc.....................  All................................           72-37-36-200-001
H. P. Turbine Shaft...........................  All................................           72-41-31-200-000
H. P. Stage 1 Rotor Disc......................  All................................           72-41-32-200-000
H. P. Turbine Stage 2 Rotor Disc..............  All................................           72-41-33-200-001
L. P. Turbine Shaft...........................  All................................           72-52-21-200-003
L. P. Turbine Stage 1 Rotor Disc..............  All................................           72-52-22-200-000
L. P. Turbine Stage 2 Rotor Disc..............  All................................           72-52-23-200-000
L. P. Turbine Stage 3 Rotor Disc..............  All................................         72-52-24-200-000''
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[[Page 63012]]

    (b) Except as provided in paragraph (c) of this AD, and 
notwithstanding contrary provisions in Sec. 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these mandatory inspections 
shall be performed only in accordance with the TLM and applicable 
Engine Manual.

Alternative Method 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 Engine Certification Office. Operators must 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector (PMI), who may add comments and then send it 
to the Engine Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    (d) Special flight permits may be issued in accordance with 
Secs. 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 accomplished.
    (e) The records of the mandatory inspections required as a 
result of revising the TLM and the applicable Engine Manual and the 
air carrier's continuous airworthiness maintenance program as 
provided by paragraph (a) of this AD shall be maintained by FAA-
certificated air carriers which have an approved continuous 
airworthiness maintenance program in accordance with the record 
keeping system currently specified in their manual required by 
Sec. 121.369 of the Federal Aviation Regulations (14 CFR 121.369); 
or, in lieu of the record showing the current status of each 
mandatory inspection required by Sec. 121.380(a)(2)(vi) of the 
Federal Aviation Regulations (14 CFR 121.380(a)(2)(vi)), 
certificated air carriers may establish an approved alternate system 
of record retention that provides a method for preservation and 
retrieval of the maintenance records that include the inspections 
resulting from this AD, and include the policy and procedures for 
implementing this alternate method in the air carrier's maintenance 
manual required by Sec. 121.369 (c) of the Federal Aviation 
Regulations (14 CFR 121.369 (c)); however, the alternate system must 
be accepted by the appropriate PMI and require the maintenance 
records be maintained either indefinitely or until the work is 
repeated.

    Note 3: These record keeping requirements apply only to the 
records used to document the mandatory inspections required as a 
result of revising the ALS and the MSS of the Instructions for 
Continued Airworthiness in the Time Limits Manual (Chapter 05-10-00) 
of the Engine Manuals as provided in paragraph (a) of this AD, and 
do not alter or amend the record keeping requirements for any other 
AD or regulatory requirement.


    Issued in Burlington, Massachusetts, on November 27, 2001.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-29949 Filed 12-3-01; 8:45 am]
BILLING CODE 4910-13-U