2010-20351. Airworthiness Directives; Pratt & Whitney JT8D-7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR Series Turbofan Engines

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) JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR 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 TLS of the manufacturer's engine manual and an air carrier's approved continuous airworthiness maintenance program to incorporate additional inspection requirements and reduce the model applicability. Pratt & Whitney has developed and the FAA has approved improved inspection procedures for the critical life-limited parts. 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, 2010.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

FOR FURTHER INFORMATION CONTACT:

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2010-0593; Directorate Identifier 98-ANE-48-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

On December 1, 2005, the FAA issued AD 2005-25-05, Amendment 39-14398 (70 FR 73361, December 12, 2005), to require revisions to the TLS of the manufacturer's engine manual for these engines 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, Pratt & Whitney has developed and the FAA has approved improved inspection procedures for the critical life-limited parts. 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 add new inspection methods to the TLS of the manufacturer's engine manual and an air carrier's approved continuous airworthiness maintenance program to incorporate additional inspection requirements for 1st stage compressor hubs, 3rd stage turbine disks, and 4th stage turbine disks.

Removal of Obsolete Engine Models

Also since the issuance of that AD, PW notified us that engine models JT8D-1, -1A, and -1B, have either been converted to other affected engine models or retired from service.

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 PW JT8D-7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR series turbofan engines of the same type design, the proposed AD would supersede AD 2005-25-05 to add new inspection methods for 1st stage compressor hubs, 3rd stage turbine disks, and 4th stage turbine disks, and would remove the -1, -1A, and -1B engine models from the applicability. For reference, this proposed AD carries forward the requirements from AD 2005-25-05. Also for reference, parts that have an Engine Manual Inspection Task and or Sub Task Number reference updated in the table in the compliance section of this AD, are identified by an asterisk (*) that precedes the part nomenclature.

Costs of Compliance

We estimate that this proposed AD would affect 1,527 JT8D -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 10 work-hours per engine to perform the proposed actions, and that the average labor rate is $85 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, we estimate the total cost of the proposed AD to U.S. operators to be $1,297,950.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

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 the proposed AD:

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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-14398 (70 FR 73361, December 12, 2005) and by adding a new airworthiness directive to read as follows:

Pratt & Whitney: Docket No. FAA-2010-0593; Directorate Identifier 98-ANE-48-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by October 18, 2010.

Affected ADs

(b) This AD supersedes AD 2005-25-05, Amendment 39-14398.

Applicability

(c) This AD applies to Pratt & Whitney (PW) JT8D-7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR series turbofan engines. These engines are installed on, but not limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9 series airplanes.

Unsafe Condition

(d) This AD results from the need to require enhanced inspection of selected critical life-limited parts of PW JT8D series turbofan engines. 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 30 days after the effective date of this AD, (1) revise the Time Limits Section (TLS) of the manufacturer's engine manual, part number 481672, as appropriate for PW JT8D-7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR series turbofan engines, and (2) for air carriers, revise the approved mandatory inspections section of the continuous airworthiness maintenance program, by adding the following:

“Critical Life Limited Part Inspection

A. Inspection Requirements:

(1) This section has the definitions for individual engine piece parts and the inspection procedures which are necessary when these parts are removed from the engine.

(2) It is necessary to do the inspection procedures of the piece parts in paragraph B when:

(a) The part is removed from the engine and disassembled to the level specified in paragraph B and

(b) The part has accumulated more than 100 cycles since the last piece part inspection, provided that the part was not damaged or related to the cause for its removal from the engine.

(3) The inspections specified in this paragraph do not replace or make not necessary other recommended inspections for these parts or other parts.

B. Parts Requiring Inspection:

Note:

Piece part is defined as any of the listed parts with all the blades removed.

Description	Section	Inspection No.
Hub (Disk), 1st Stage Compressor:
* Hub Detail—All P/Ns	72-33-31	-03, -04, -05, -06
* Hub Assembly—All P/Ns	72-33-31	-03, -04, -05, -06
2nd Stage Compressor:
Disk—All P/Ns	72-33-33	-02, -03
Disk Assembly—All P/Ns	72-33-33	-02, -03
Disk, 13th Stage Compressor—All P/Ns	72-36-47	-02
HP Turbine Disk, First Stage w/integral Shaft—All P/Ns	72-52-04	-03
HP Turbine, First Stage, w/separable Shaft:
Rotor Assembly—All P/Ns	72-52-02	-04
Disk—All P/Ns	72-52-02	-03
Disk, 2nd Stage Turbine—All P/Ns	72-53-16	-02
* Disk, 3rd Stage Turbine—All P/Ns	72-53-17	-02, -03
* Disk (Separable), 4th Stage Turbine—All P/Ns	72-53-15	-02, -03
Disk (Integral Disk/Hub), 4th Stage Turbine—All P/Ns	72-53-18	-02”

(g) The parts that have an Engine Manual Inspection Task and or Sub Task Number reference updated in the table of this AD, are identified by an asterisk (*) that precedes the part nomenclature.

(h) Except as provided in paragraph (i) of this AD, and notwithstanding contrary provisions in section 43.16 of the Federal Aviation Regulations (14 CFR 43.16), these mandatory inspections shall be performed only in accordance with the TLS of the manufacturer's engine manual.

Alternative Methods of Compliance (AMOC)

(i) You must perform these mandatory inspections using the TLS of the manufacturer's engine manual unless you receive approval to use an AMOC under paragraph (j) 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.

(j) 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

(k) You have met the requirements of this AD when you revise the TLS of the manufacturer's engine manual as specified in paragraph (f) of this AD. For air carriers operating under part 121 of the Federal Aviation Regulations (14 CFR part 121), you have met the requirements of this AD when you modify your continuous airworthiness maintenance plan to reflect those changes. You do not need to record each piece-part inspection as compliance to this AD, but you must maintain records of those inspections according to the regulations governing your operation. For air carriers operating under part 121, you may use either the system established to comply with section 121.369 or an alternative accepted by your principal maintenance inspector if that alternative:

(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.

(l) These record keeping requirements apply only to the records used to document the mandatory inspections required as a result of revising the TLS of the manufacturer's engine manual as specified in paragraph (f) of this AD. These record keeping requirements do not alter or amend the record keeping requirements for any other AD or regulatory requirement.

Related Information

(m) Contact Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone], fax [phone], for more information about this AD.

Issued in Burlington, Massachusetts, on August 6, 2010.

Peter A. White,

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