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Proposed Rule

Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

Document Details

Information about this document as published in the Federal Register.

Published Document

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Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

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: 9-ane-adcomment@faa.gov.

You may examine the AD docket at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

Start Further Info

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.

End Further Info End Preamble Start Supplemental Information

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-Start Printed Page 51201part 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 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:

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
Hub, Front CompressorAll72-31-07Insp/Check-0251A357
Hub, Turbine, Front Assembly (Stage 1)All72-52-05Insp/Check-0251A357
Hub, Turbine, Intermediate Rear (Stage 2)All72-52-06Insp/Check-0251A357

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

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
Hub, LPC AssemblyAll72-31-07Insp/Check-0251A357
Hub, Turbine, Front Assembly (Stage 1)All72-52-05Insp/Check-0251A357
Seal—Air, HPT Stage 2All72-52-22Insp/Check-0251A357
Hub, Turbine, Rear (Stage 2)All72-52-06Insp/Check-0251A357
Start Printed Page 51202

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

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
Hub, LPC AssemblyAll72-31-07Insp/Check-0251A750
Seal—Air, HPT Stage 1All72-52-19Insp/Check-0251A750
Hub, Turbine, Front Assembly (Stage 1)All72-52-05Insp/Check-0251A750
Seal—Air, HPT Stage 2 AssemblyAll72-52-22Insp/Check-0251A750
Hub, Turbine Rear Assembly (Stage 2)All72-52-06Insp/Check-0251A750

For Engine Manuals 50A443, 50A605, and 50A822, add the following table data:

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
HPC Stage 5 DiskAll72-35-06Insp/Check-0251A357
HPC Front Drum RotorAll72-35-07Insp/Check-0251A357
HPC Rear Drum RotorAll72-35-08Insp/Check-0251A357
HPC Rear Drum RotorAll72-35-10Insp/Check-0251A357

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

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
HPC Stage 5 DiskAll72-35-06Insp/Check-0251A357
HPC Front Drum RotorAll72-35-07Insp/Check-0251A357
HPC Rear Drum RotorAll72-35-10Insp/Check-0251A357

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

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
HPC Stage 5 DiskAll72-35-06Insp/Check-0251A750
HPC Front Drum RotorAll72-35-07Insp/Check-0251A750
HPC Rear Drum RotorAll72-35-10Insp/Check-0251A750
HPC Stage 15 DiskAll72-35-92Insp/Check-0251A750
HPT Stage 1 AirsealAll72-52-19Insp/Check-0251A750
HPT Front HubAll72-52-05Insp/Check-0251A750
HPT Stage 2 AirsealAll72-52-22Insp/Check-0251A750
HPT Rear HubAll72-52-06Insp/Check-0251A750

For Engine Manuals 50A443, 50A605 and 50A822, add the following table data:

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
Stage 3 LPT DiskAll72-53-13Insp/Check-0251A357
Stage 4 LPT DiskAll72-53-14Insp/Check-0251A357
Stage 5 LPT DiskAll72-53-15Insp/Check-0251A357
Stage 6 LPT DiskAll72-53-16Insp/Check-0251A357

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

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
Stage 3 LPT DiskAll72-53-13Insp/Check-0251A357
Stage 4 LPT DiskAll72-53-14Insp/Check-0251A357
Stage 5 LPT DiskAll72-53-15Insp/Check-0251A357
Start Printed Page 51203
Stage 6 LPT DiskAll72-53-16Insp/Check-0251A357
Stage 7 LPT DiskAll72-53-61Insp/Check-0251A357

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

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
Stage 3 LPT DiskAll72-53-13Insp/Check-02, Config-151A750
Stage 4 LPT DiskAll72-53-14Insp/Check-0251A750
Stage 5 LPT DiskAll72-53-60Insp/Check-0251A750
Stage 6 LPT DiskAll72-53-16Insp/Check-02, Config-151A750
Stage 7 LPT DiskAll72-53-72Insp/Check-0251A750
Stage 8 LPT DiskAll72-53-62Insp/Check-02, Config-151A750
Stage 9 LPT DiskAll72-53-63Insp/Check-0251A750

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

Part nomenclaturePart No.CIR manual sectionCIR manual inspectionCIR manual
Stage 3 LPT DiskAll72-53-13Insp/Check-02, Config-2 See Note (1)51A750
Stage 4 LPT DiskAll72-53-14Insp/Check-0251A750
Stage 5 LPT DiskAll72-53-60Insp/Check-0251A750
Stage 6 LPT DiskAll72-53-16Insp/Check-02, Config-2 See Note (1)51A750
Stage 7 LPT DiskAll72-53-72Insp/Check-0251A750
Stage 8 LPT DiskAll72-53-62Insp/Check-02, Config-2 See Note (1)51A750
Stage 9 LPT DiskAll72-53-63Insp/Check-0251A750

(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.

Start Signature

Issued in Burlington, Massachusetts, on August 12, 2004.

Ann Mollica,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 04-18924 Filed 8-17-04; 8:45 am]

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