[Federal Register Volume 66, Number 194 (Friday, October 5, 2001)]
[Proposed Rules]
[Pages 50888-50891]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-25055]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 14 CFR Part 39

[Docket No. 98-ANE-66-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to Pratt & Whitney (PW) PW4000 
series turbofan engines, that currently requires revisions to the Time 
Limits Section of the manufacturer's Engine Manuals (EMs) to include 
required enhanced inspection of selected critical life-limited parts at 
each piece-part exposure. This proposal would modify the airworthiness 
limitations section of the manufacturer's manual and an air carrier's 
approved continuous airworthiness maintenance program to incorporate 
additional inspection requirements. 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 December 4, 2001.

ADDRESSES: Submit comments to the Federal Aviation Administration 
(FAA), New England Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 98-ANE-66-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299. 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. 
Comments may be inspected at this location by appointment between 8 
a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Robert McCabe, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7138, 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 notice 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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-ANE-66-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    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. 98-ANE-66-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On June 5, 2000, the Federal Aviation Administration (FAA) issued 
airworthiness directive (AD) 2000-12-02, Amendment 39-11780 (65 FR 
37473, June 15, 2000), to require revisions to the Time Limits Section 
in the Engine Manuals (EMs) for certain Pratt & Whitney (PW) PW4000 
series turbofan engines to include required enhanced inspection of 
selected critical life-limited rotating components in the fan rotor at 
each piece-part exposure.

[[Page 50889]]

New Inspection Procedures

    Since the issuance of that AD, an FAA study of in-service events 
involving uncontained failures of critical rotating engine parts has 
indicated the need for additional 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. This proposal would modify the time limitations 
section of the manufacturer's manual and an air carrier's approved 
continuous airworthiness maintenance program to incorporate additional 
inspection requirements.

Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 2000-12-02 to require the additional 
critical life-limited rotating engine parts to be subject to focused 
inspection at each piece-part opportunity.

Economic Analysis

    The FAA estimates that 500 engines installed on airplanes of US 
registry would be affected by this proposed AD, and that it would take 
approximately 10 work hours per engine to accomplish the proposed 
actions. The average labor rate is $60 per work hour, the average Shop 
Visit Rate is .097, and the average usage is 3,250hrs/year/engine. 
Based on these figures, the total cost impact of the proposed AD on US 
operators is estimated to be about $94,000 per year.

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 removing Amendment 39-11780 (65 FR 
37473, June 15, 2000), and by adding a new airworthiness directive, to 
read as follows:

Pratt & Whitney: Docket No. 98-ANE-66-AD. Supersedes AD 2000-12-02, 
Amendment 39-11780.

    Applicability: Pratt & Whitney (PW) Model PW4050, PW4052, 
PW4056, PW4060, PW4060A, PW4060C, PW4062, PW4152, PW4156, PW4156A, 
PW4158, PW4160, PW4460, PW4462, PW4168, PW4168A, PW4164, PW4074, 
PW4074D, PW4077, PW4077D, PW4084, PW4084D, PW4090, PW4090-3, 
PW4090D, and PW4098 turbofan engines, installed on but not limited 
to Airbus A300, A310, and A330 series, Boeing 747, 767, and 777 
series, and McDonnell Douglas MD-11 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 (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: 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:

Inspections

    (a) Within the next 30 days after the effective date of this AD, 
(1) revise the Time Limits section of the manufacturer's Engine 
Manual, Part Numbers 50A342, 50A345, 50A443, 50A605, 50A751, 51A342, 
50A822, 51A751 and 51A345, as appropriate for the Pratt & Whitney 
PW4050, PW4052, PW4056, PW4060, PW4060A, PW4062, PW4060C, PW4152, 
PW4156, PW4156A, PW4158, PW4160, PW4460, PW4462, PW4164, PW4168, 
PW4168A, PW4074, PW4074D, PW4077, PW4077D, PW4084, PW4084D, PW4090, 
PW4090-3, PW4090D, and PW4098 series turbofan engines, and (2) for 
air carrier's, revise the approved mandatory inspections section of 
the continuous airworthiness maintenance program, by adding the 
following: ``MANDATORY INSPECTIONS
    (1) Perform inspections of the following parts at each piece-
part opportunity in accordance with the instructions provided in the 
PW4000 series Engine Cleaning, Inspection and Repair (CIR) Manuals:
    For Engine Manuals 50A443, 50A605, and 50A822, add the following 
table data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
Hub, Front Compressor............  All.................     72-31-07  Insp/Check-02.......  51A357
Hub, Turbine Front Assy (Stage 1)  All.................     72-52-05  Insp/Check-02.......  51A357
Hub, Turbine Intermediate Rear     All.................     72-52-06  Insp/Check-02.......  51A357
 (Stage 2).
----------------------------------------------------------------------------------------------------------------

    For Engine Manual 50A342, add the following table data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
Hub, LPC Assembly................  All.................     72-31-07  Insp/Check-02.......  51A357
Hub, Turbine Front Assembly        All.................     72-52-05  Insp/Check-02.......  51A357
 (Stage 1).
Seal--Air, HPT 2nd Stage.........  All.................     72-52-22  Insp/Check-02.......  51A357

[[Page 50890]]

 
Hub, Turbine Rear (Stage 2)......  All.................     72-52-06  Insp/Check-02.......  51A357
----------------------------------------------------------------------------------------------------------------

    For Engine Manuals 50A345 and 50A751, add the following table 
data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
Hub, LPC Assembly................  All.................     72-31-07  Insp/Check-02.......  51A750
Seal--Air, HPT 1st Stage.........  All.................     72-52-19  Insp/Check-02.......  51A750
Hub, Turbine Front Assembly (1st   All.................     72-52-05  Insp/Check-02.......  51A750
 Stage).
Seal--Air, HPT 2nd Stage Assembly  All.................     72-52-22  Insp/Check-02.......  51A750
Hub, Turbine rear Assembly (2nd    All.................     72-52-06  Insp/Check-02.......  51A750
 Stage).
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    For Engine Manuals 50A443, 50A605, and 50A882, add the following 
table data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
HPC 5th Stage Disk...............  All.................  (\1\) 72-35  Insp/Check-02.......  51A357
                                                                 -06
HPC Front Drum Rotor.............  All.................  (\1\) 72-35  Insp/Check-02.......  51A357
                                                                 -07
HPC Rear Drum Rotor..............  All.................  (\2\) 72-35  Insp/Check-02.......  51A357
                                                                 -08
HPC Rear Drum Rotor..............  All.................  (\3\) 72-35  Insp/Check-02.......  51A357
                                                                 -10
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(\1\) For PW4000-94'' Phase I & III ONLY.
(\2\) For PW4000-94'' Phase I ONLY.
(\3\) For PW4000-94'' Phase III ONLY.

    For Engine Manuals 51A342, add the following table data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
HPC 5th Stage Disk...............  All.................     72-35-06  Insp/Check-02.......  51A357
HPC Front Drum Rotor.............  All.................     72-35-07  Insp/Check-02.......  51A357
HPC Rear Drum Rotor..............  All.................     72-35-10  Insp/Check-02.......  51A357
----------------------------------------------------------------------------------------------------------------

    For Engine Manuals 51A345 and 51A751, add the following table 
data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
HPC 5th Stage Disk...............  All.................     72-35-06  Insp/Check-02.......  51A750
HPC Front Drum Rotor.............  All.................     72-35-07  Insp/Check-02.......  51A750
HPC Rear Drum Rotor..............  All.................     72-35-10  Insp/Check-02.......  51A750
HPC 15th Stage Disk..............  All.................     72-35-92  Insp/Check-02.......  51A750
HPT 1st Stage Airseal............  All.................     72-52-19  Insp/Check-02.......  51A750
HPT Front Hub....................  All.................     72-52-05  Insp/Check-02.......  51A750
HPT 2nd Stage Airseal............  All.................     72-52-22  Insp/Check-02.......  51A750
HPT Rear Hub.....................  All.................     72-52-06  Insp/Check-02.......  51A750
----------------------------------------------------------------------------------------------------------------

    For Engine Manuals 50A443, 50A605, and 50A882, add the following 
table data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
Stage 3 LPT Disk.................  All.................     72-53-13  Insp/Check-02.......  51A357
Stage 4 LPT Disk.................  All.................     72-53-14  Insp/Check-02.......  51A357
Stage 5 LPT Disk.................  All.................     72-53-15  Insp/Check-02.......  51A357
Stage 6 LPT Disk.................  All.................     72-53-16  Insp/Check-02.......  51A357
----------------------------------------------------------------------------------------------------------------

    For Engine Manual 51A342, add the following table data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
Stage 3 LPT Disk.................  All.................     72-53-13  Insp/Check-02.......  51A357
Stage 4 LPT Disk.................  All.................     72-53-14  Insp/Check-02.......  51A357
Stage 5 LPT Disk.................  All.................     72-53-15  Insp/Check-02.......  51A357
Stage 6 LPT Disk.................  All.................     72-53-16  Insp/Check-02.......  51A357
Stage 7 LPT Disk.................  All.................     72-53-61  Insp/Check-02.......  51A357
----------------------------------------------------------------------------------------------------------------


[[Page 50891]]

    For Engine Manual 51A345, add the following table data:

----------------------------------------------------------------------------------------------------------------
                                                          CIR manual       CIR manual
        Part nomenclature                Part No.          section         inspection            CIR manual
----------------------------------------------------------------------------------------------------------------
Stage 3 LPT Disk.................  All.................     72-53-13  Insp/Check-02,        51A750
                                                                       Config-1.
Stage 4 LPT Disk.................  All.................     72-53-14  Insp/Check-02.......  51A750
Stage 5 LPT Disk.................  All.................     72-53-60  Insp/Check-02.......  51A750
Stage 6 LPT Disk.................  All.................     72-53-16  Insp/Check-02,        51A750
                                                                       Config-1.
Stage 7 LPT Disk.................  All.................     72-53-72  Insp/Check-02.......  51A750
Stage 8 LPT Disk.................  All.................     72-53-62  Insp/Check-02,        51A750
                                                                       Config-1.
Stage 9 LPT Disk.................  All.................     72-53-63  Insp/Check-02.......  51A750
----------------------------------------------------------------------------------------------------------------

    For Engine Manual 51A751, add the following table data:

----------------------------------------------------------------------------------------------------------------
                                                                CIR manual
          Part nomenclature                   Part No.           section     CIR manual inspection    CIR manual
----------------------------------------------------------------------------------------------------------------
Stage 3 LPT Disk....................  All....................     72-53-13  Insp/Check-02, Config-        51A750
                                                                             2. See Note (1).
Stage 4 LPT Disk....................  All....................     72-53-14  Insp/Check-02..........       51A750
Stage 5 LPT Disk....................  All....................     72-53-60  Insp/Check-02..........       51A750
Stage 6 LPT Disk....................  All....................     72-53-16  Insp/Check-02, Config-        51A750
                                                                             2. See Note (1).
Stage 7 LPT Disk....................  All....................     72-53-72  Insp/Check-02..........       51A750
Stage 8 LPT Disk....................  All....................     72-53-62  Insp/Check-02, Config-        51A750
                                                                             2. See Note (1).
Stage 9 LPT Disk....................  All....................     72-53-63  Insp/Check-02..........      51A750
----------------------------------------------------------------------------------------------------------------
(1) FPI method only.

    (2) For the purposes of these mandatory inspections, piece-part 
opportunity means:
    (i) The part is considered completely disassembled when done in 
accordance with the disassembly instructions in the manufacturers 
engine manual; and
    (ii) The part has accumulated more than 100 cycles in service 
since the last piece-part opportunity inspection, provided that the 
part was not damaged or related to the cause for its removal from 
the engine.''
    (b) Except as provided in paragraph (d) of this AD, and 
notwithstanding contrary provisions in section 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these enhanced inspections 
shall be performed only in accordance with the TLS of the 
appropriate PW4000 series Engine Manuals.

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 shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, 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.

Special Flight Permits

    (d) 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 airplane to a location where 
the requirements of this AD can be accomplished.

Continuous Airworthiness Maintenance Program

    (e) The record of the mandatory inspections required as a result 
of revising the Time Limits of the PW4000 series Engine Manuals as 
provided by paragraph (a) of this AD shall be maintained by FAA 
certificated air carriers who have an approved continuous 
airworthiness maintenance program in accordance with the record 
keeping system currently specified in their manual required by 
sections 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 sections 121.380(a)(2)(vi) of 
the Federal Aviation Regulations (14 CFR 121.380(a)(2)(vi)), 
certificated air carriers may establish an alternate system of 
record retention that provides a method for preservation and 
retrieval of the maintenance record that includes the inspections 
resulting from this AD, and include the policy and procedures for 
implementing this alternate method in the manual required by 
sections 121.369 (c) of the Federal Aviation Regulations (14 CFR 
121.369 (c)) provided the alternate system must require the 
maintenance record 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 enhanced inspections required 
as a result of revising the Time Limits section of the PW4000 series 
Engine Manuals as provided in paragraph (a) of this AD, and do not 
alter 1 or amend the record keeping requirements for any other AD or 
regulatory requirement.


    Issued in Burlington, Massachusetts, on October 1, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 01-25055 Filed 10-4-01; 8:45 am]
BILLING CODE 4910-13-P