[Federal Register Volume 69, Number 159 (Wednesday, August 18, 2004)]
[Proposed Rules]
[Pages 51200-51203]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-18924]


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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 (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for Pratt & Whitney (PW) PW4000 series turbofan engines. 
That AD currently requires revisions to the engine manufacturer's time 
limits section (TLS) to include enhanced inspection of selected 
critical life-limited parts at each piece-part opportunity. This 
proposed AD would modify the airworthiness limitations section of the 
manufacturer's manuals and an air carrier's approved continuous 
airworthiness maintenance program to add additional inspection 
requirements for PW4000-94'' engine models only. This proposed AD would 
also add the PW4062A engine to the applicability. 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. We are proposing this AD to prevent 
critical life-limited rotating engine part failure, which could result 
in an uncontained engine failure and damage to the airplane.

DATES: We must receive any comments on this proposed AD by October 18, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     By mail: 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.
     By fax: (781) 238-7055.
     By e-mail: [email protected].
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7146, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. 98-ANE-66-AD'' in the 
subject line of your comments. If you want us to acknowledge receipt of 
your mailed comments, send us a self-addressed, stamped postcard with 
the docket number written on it; we will date-stamp your postcard and 
mail it back to you. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. If a person contacts us verbally, and that contact relates to a 
substantive part of this proposed AD, we will summarize the contact and 
place the summary in the docket. We will consider all comments received 
by the closing date and may amend the proposed AD in light of those 
comments.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You may get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Discussion

    On February 5, 2002, the FAA issued AD 2002-03-08, Amendment 39-
12649 (67 FR 7061, February 15, 2002), to require revisions to the Time 
Limits Section (TLS) of the PW4000 series Turbofan Engine Manuals to 
include required enhanced inspection of selected critical life-limited 
parts at each piece-part opportunity.

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 add focused eddy 
current inspections of front compressor hubs on PW4000-94'' engine 
models.

FAA's Determination of an Unsafe Condition and Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other PW4000 series turbofan engines of the same 
type design, the proposed AD would supersede AD 2002-03-08 to add 
focused eddy current inspections of front compressor hubs on PW4000-
94'' engine models to be done at each piece-

[[Page 51201]]

part opportunity, and to add the PW4062A engine model to the 
applicability.

Costs of Compliance

    There are about 2,625 Pratt & Whitney PW4000 series turbofan 
engines of the affected design in the worldwide fleet. We estimate that 
600 engines installed on airplanes of U.S. registry would be affected 
by this proposed AD. We also estimate that it would take about 10 work 
hours per engine to perform the proposed inspections, and that the 
average labor rate is $65 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 additional cost per engine per shop visit is estimated to be 
$650. Based on the current PW4000 engine shop visit rate, the total 
additional cost for the PW4000 fleet is estimated to be $123,000 per 
year.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    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. Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a summary of the costs to comply with this proposal and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 98-ANE-66-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by removing Amendment 39-12649, (67 
FR 7061, June 4, 2002), and by adding a new airworthiness directive to 
read as follows:

Pratt & Whitney: Docket No. 98-ANE-66-AD supersedes AD 2002-03-08, 
Amendment 39-12649.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by October 18, 
2004.

Affected ADs

    (b) This AD supersedes AD 2002-03-08.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) Models PW4050, 
PW4052, PW4056, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4152, 
PW4156, PW4156A, PW4158, PW4160, PW4460, PW4462, PW4650, PW4164, 
PW4168, PW4168A, PW4074, PW4074D, PW4077, PW4077D, PW4084, PW4084D, 
PW4090, PW4090-3, PW4090D, and PW4098 turbofan engines. These 
engines are 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.

Unsafe Condition

    (d) This AD results from the need to add additional inspection 
requirements for PW4000-94'' engine models only, and to add the 
PW4062A engine to the applicability. We are issuing this AD to 
prevent critical life-limited rotating engine part failure, which 
could result in an uncontained engine failure and damage to the 
airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.
    (f) Within the next 60 days after the effective date of this AD, 
revise the Time Limits Section (TLS) of the Engine Manuals (EMs), 
part numbers 50A443, 50A605, 50A822, 51A342, 51A345, and 51A751, as 
applicable, for PW Models PW4050, PW4052, PW4056, PW4060, PW4060A, 
PW4060C, PW4062, PW4062A, PW4152, PW4156, PW4156A, PW4158, PW4160, 
PW4460, PW4462, PW4650, PW4164, PW4168, PW4168A, PW4074, PW4074D, 
PW4077, PW4077D, PW4084, PW4084D, PW4090, PW4090-3, PW4090D, and 
PW4098 turbofan turbofan engines, and for air carriers revise the 
approved 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
         Part nomenclature                 Part No.            section     CIR manual inspection    CIR manual
----------------------------------------------------------------------------------------------------------------
Hub, Front Compressor.............  All..................        72-31-07  Insp/Check-02........  51A357
Hub, Turbine, Front Assembly        All..................        72-52-05  Insp/Check-02........  51A357
 (Stage 1).
Hub, Turbine, Intermediate Rear     All..................        72-52-06  Insp/Check-02........  51A357
 (Stage 2).
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    For Engine Manual 51A342, add the following table data:

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                                                             CIR manual
         Part nomenclature                 Part No.            section     CIR manual 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 Stage 2............  All..................        72-52-22  Insp/Check-02........  51A357
Hub, Turbine, Rear (Stage 2)......  All..................        72-52-06  Insp/Check-02........  51A357
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[[Page 51202]]

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

----------------------------------------------------------------------------------------------------------------
                                                             CIR manual
         Part nomenclature                 Part No.            section     CIR manual inspection    CIR manual
----------------------------------------------------------------------------------------------------------------
Hub, LPC Assembly.................  All..................        72-31-07  Insp/Check-02........  51A750
Seal--Air, HPT Stage 1............  All..................        72-52-19  Insp/Check-02........  51A750
Hub, Turbine, Front Assembly        All..................        72-52-05  Insp/Check-02........  51A750
 (Stage 1).
Seal--Air, HPT Stage 2 Assembly...  All..................        72-52-22  Insp/Check-02........  51A750
Hub, Turbine Rear Assembly (Stage   All..................        72-52-06  Insp/Check-02........  51A750
 2).
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    For Engine Manuals 50A443, 50A605, and 50A822, add the following 
table data:

----------------------------------------------------------------------------------------------------------------
                                                             CIR manual
         Part nomenclature                 Part No.            section     CIR manual inspection    CIR manual
----------------------------------------------------------------------------------------------------------------
HPC Stage 5 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..................        72-35-08  Insp/Check-02........  51A357
HPC Rear Drum Rotor...............  All..................        72-35-10  Insp/Check-02........  51A357
----------------------------------------------------------------------------------------------------------------

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

----------------------------------------------------------------------------------------------------------------
                                                             CIR manual
         Part nomenclature                 Part No.            section     CIR manual inspection    CIR manual
----------------------------------------------------------------------------------------------------------------
HPC Stage 5 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
         Part nomenclature                 Part No.            section     CIR manual inspection    CIR manual
----------------------------------------------------------------------------------------------------------------
HPC Stage 5 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 Stage 15 Disk.................  All..................        72-35-92  Insp/Check-02........  51A750
HPT Stage 1 Airseal...............  All..................        72-52-19  Insp/Check-02........  51A750
HPT Front Hub.....................  All..................        72-52-05  Insp/Check-02........  51A750
HPT Stage 2 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 50A822, 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........  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
         Part nomenclature                 Part No.            section     CIR manual 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

[[Page 51203]]

 
Stage 6 LPT Disk..................  All..................        72-53-16  Insp/Check-02........  51A357
Stage 7 LPT Disk..................  All..................        72-53-61  Insp/Check-02........  51A357
----------------------------------------------------------------------------------------------------------------

    For Engine Manual 51A345, 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
                                                                            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
                                                                            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
                                                                            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 manufacturer's 
engine manual to either part number level listed in the table above, 
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.''

Alternative Methods of Compliance

    (g) You must perform these mandatory inspections using the TLS 
and the applicable Engine Manual unless you receive approval to use 
an alternative method of compliance under paragraph (h) of this AD. 
Section 43.16 of the Federal Aviation Regulations (14 CFR 43.16) may 
not be used to approve alternative methods of compliance or 
adjustments to the times in which these inspections must be 
performed.
    (h) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Maintaining Records of the Mandatory Inspections

    (i) You have met the requirements of this AD by using a TLS of 
the manufacturer's engine manual changed as specified in paragraph 
(f) of this AD, and, for air carriers operating under part 121 of 
the Federal Aviation Regulations (14 CFR part 121), by modifying 
your continuous airworthiness maintenance plan to reflect those 
changes. You must maintain records of the mandatory inspections that 
result from those changes to the TLS according to the regulations 
governing your operation. You do not need to record each piece-part 
inspection as compliance to this AD. For air carriers operating 
under part 121, you may use either the system established to comply 
with section 121.369 or use an alternative system that your 
principal maintenance inspector has accepted if that alternative 
system:
    (1) Includes a method for preserving and retrieving the records 
of the inspections resulting from this AD; and
    (2) Meets the requirements of section 121.369(c); and
    (3) Maintains the records either indefinitely or until the work 
is repeated.
    (j) These record keeping requirements apply only to the records 
used to document the mandatory inspections required as a result of 
revising the TLS as specified in paragraph (f) of this AD, and do 
not alter or amend the record keeping requirements for any other AD 
or regulatory requirement.

Related Information

    (k) None.

    Issued in Burlington, Massachusetts, on August 12, 2004.
Ann Mollica,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-18924 Filed 8-17-04; 8:45 am]
BILLING CODE 4910-13-P