01-28707. Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This action revises an earlier proposed airworthiness directive (AD), applicable to certain Pratt & Whitney JT9D series turbofan engines, that would supersede an existing airworthiness directive (AD) by adding additional critical life-limited parts for enhanced inspection. That proposal was prompted by an FAA study of in-service events involving uncontained failures of critical rotating engine parts. This action revises the proposed rule by adding rear compressor drive turbine shafts to the parts to be included in the revision to the manufacturer's Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA), and the approved continuous airworthiness maintenance program for air carrier operations. 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 20, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-47-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8:00 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: “[e-mail].” Comments sent via the Internet must contain the docket number in the subject line.

FOR FURTHER INFORMATION CONTACT:

Tara Goodman, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone [phone], fax [phone].

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 Docket Number 98-ANE-47-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. 98-ANE-47-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to certain Pratt & Whitney JT9D series turbofan engines, was published as a notice of proposed rulemaking (NPRM) in the Federal Register on October 10, 2001 (66 FR 51609). That NPRM would have modified the airworthiness limitations section of the manufacturer's manual and air carrier's approved continuous airworthiness maintenance program to incorporate additional inspection requirements. That NPRM was prompted by an FAA study of in-service events involving uncontained failures of critical rotating engine parts. That condition, if not corrected, could result in an uncontained engine failure and damage to the airplane.

Since the issuance of that NPRM, the FAA has become aware that rear compressor drive turbine shafts were inadvertantly omitted from the list of parts for enhanced inspection, and must be added. This proposal would add to that NPRM, modification of the airworthiness limitations section of the manufacturer's manual and air carrier's approved continuous airworthiness maintenance program to incorporate additional inspection requirements.

Since this change expands the scope of the originally proposed rule, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Economic Analysis

The FAA estimates that 837 engines installed on airplanes of US registry would be affected by this proposed AD, that it would take approximately 1 work hour per engine to do the proposed actions. The average labor rate is $60 per work hour. Based on these figures the total cost impact of the proposed AD on U.S. operators is estimated to be $954,180.

Regulatory Analysis

The regulations adopted herein will 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. Therefore, it is determined that this action does not have federalism implications under Executive Order (EO) 13132.

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 effect, 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.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Pratt & Whitney: Docket No. 98-ANE-47-AD. Supersedes AD 2000-01-13, Amendment 39-11511.

Applicability

This airworthiness directive (AD) is applicable to Pratt & Whitney (PW) JT9D-3A, -7, -7A, -7H, -7AH, -7F, -7J, -20J, -59A, -70A, -7Q, -7Q3, -7R4D, -7R4D1, -7R4E, -7R4E1, -7R4E4, -7R4G2, and -7R4H1 series turbofan engines, installed on but not limited to Boeing 747 and 767 series, McDonnell Douglas DC-10 series, and Airbus Industrie A300 and A310 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, do the following:

Inspections

(a) Within the next 30 days after the effective date of this AD, revise the manufacturer's Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA), and for air carrier operations 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 applicable manual provisions:

Engine model	Engine manual part number	Part nomenclature	FPI per manual section	Inspection
7/7A/7AH/7F, 7H/7J/20/20J	646028 (or the equivalent customized versions, 770407 and 770408)	All Fan Hubs	72-31-04	02
		All HPC Stage 5-15 Disks and Rear Compressor Drive Turbine Shafts	72-35-00	03
		All HPT Stage 1-2 Disks and Hubs	72-51-00	03
		All LPT Stage 3-6 Disks	72-52-00	03
59A/70A	754459	All Fan Hubs	72-31-00	Heavy Maintenance Check.
		All HPC Stage 5-15 Disks and Rear Compressor Drive Turbine Shafts	72-35-00	Heavy Maintenance Check.
		All HPT Stage 1-2 Disks and Hubs	72-51-00	Heavy Maintenance Check-3.
		All LPT Stage 3-6 Disks	72-52-00	Heavy Maintenance Check-3.
7Q/7Q3	777210	All Fan Hubs	72-31-00	03
		All HPC Stage 5-15 Disks and Rear Compressor Drive Turbine Shafts	72-35-00	03
		All HPT Stage 1-2 Disks and Hubs	72-51-00	03
		All LPT State 3-6	72-52-00	03
7R4	785058, 785059, and 789328	All Fan Hubs	72-31-00	03
		All HPC Stage 5-15 Disks and Rear Compressor Drive Turbine Shafts	72-35-00	03
		All HPT Stage 1-2 Disks and Hubs	72-51-00	03
		All LPT Stage 3-6	72-52-00	03
* P/N 770407 and 770408 are customized versions of P/N 646028 engine manual.

(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; 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 (c) of this AD, and notwithstanding contrary provisions in section 43.16 of the Federal Aviation Regulations (14 CFR 43.16), these mandatory inspections must be performed only in accordance with the ALS of the manufacturer's ICA.

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

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO.

Special Flight Permits

(d) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be done.

Continuous Airworthiness Maintenance Program

(e) FAA-certificated air carriers that have an approved continuous airworthiness maintenance program in accordance with the record keeping requirement of § 121.369(c) of the Federal Aviation Regulations (14 CFR 121.369(c)) of this chapter must maintain records of the mandatory inspections that result from revising the Time Limits section of the Instructions for Continuous Airworthiness (ICA) and the air carrier's continuous airworthiness program. Alternatively, certificated air carriers may establish an approved 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 § 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. Records of the piece-part inspections are not required under § 121.380(a)(2)(vi) of the Federal Aviation Regulations (14 CFR 121.380 (a)(2)(vi). All other operators must maintain the records of mandatory inspections required by the applicable regulations governing their operations.

Note 3:

The requirements of this AD have been met when the engine manual changes are made and air carriers have modified their continuous airworthiness maintenance plans to reflect the requirements in the Engine Manuals.

Issued in Burlington, Massachusetts, on November 8, 2001.

Diane S. Romanosky,

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