# AGENCY:

 Federal Aviation Administration, DOT. 

# ACTION:

 Final rule. 

# SUMMARY:

 This amendment supersedes an existing airworthiness directive (AD), applicable to certain Pratt & Whitney JT9D series turbofan engines, that currently requires revisions to the Airworthiness Limitations Section (ALS) of the manufacturer's Instructions for Continued Airworthiness (ICA) to include required enhanced inspection of selected critical life-limited parts at each piece-part exposure. This action adds additional critical life-limited parts for enhanced inspection. This amendment is prompted by additional focused inspection procedures for other critical life-limited rotating engine parts that have been developed by the manufacturer. The actions specified by this 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:

 Effective February 23, 2000. 

# ADDRESSES:

 The information referenced in this AD may be examined at the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA. 

# FOR FURTHER INFORMATION CONTACT:

 Wego Wang, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7134, fax (781) 238-7199. 

# SUPPLEMENTARY INFORMATION:

                     A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding (AD) 99-08-12, Amendment 39-11118 (64 FR 17954, April 13, 1999), that is applicable to Pratt & Whitney (PW) JT9D series turbofan engine was published in the                     **Federal Register**                     on August 16, 1999 (64 FR 44446). That action proposed to require revisions to the Time Limits section in the Engine Manual (EM) for certain Pratt & Whitney (PW) JT9D series turbofan engines to include required enhanced inspection of selected critical life-limited parts at each piece-part exposure.                 

Since the issuance of that AD, additional focused inspection procedures for other critical life-limited rotating engine parts have been developed by PW. 

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the two comments received. 

Both commenters suggest having the same format for the two tables in the AD. One also suggests using the term “all” rather than individual part numbers to simplify recordkeeping tasks for the operators. The FAA concurs with their suggestions, and has combined the two tables into one and substituted the word “all” rather than using specific part numbers. . 

No comments were received on the economic analysis contained in the proposed rules. Based on that analysis, the FAA has determined that the annual per engine cost of $60 does not create a significant economic impact on small entities. 

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. 

                    For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from 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

## Adoption of the Amendment 

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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 

2. Section 39.13 is amended by removing Amendment 39-11118 ( 63 FR 40220, April 13, 1999), and by adding a new airworthiness directive, to read as follows: 

**AD 2000-01-13 Pratt & Whitney:**                         Amendment 39-11511 Docket No. 98-ANE-47-AD. Supersedes AD 99-08-12, Amendment 39-11118.                     

#### Applicability: 

Pratt & Whitney (PW) JT9D-7, -7A, -7H, -7AH, -7F, -7J, -20, -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:*                         Required as indicated, unless accomplished previously. For all the fan hubs and HPT disks listed in the following tables, the focused inspections should shall be conducted per the applicable documents.                     

                        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:                         Start Printed Page 2865

(a) Within the next 35 days after the effective date of this AD, revise the Engine Time Limits Section (TLS) of the Engine Manual (EM), JT9D Part Numbers 646028, 754459, 770407, 770408, 777210, 785058, 785059, 789328, as indicated below, and for air carrier operations revise as appropriate 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: 

(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 shall be performed only in accordance with the ALS of the manufacturer's ICA. 

(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 (ECO). Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector (PMI), who may add comments and then send it to the 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.

(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. 

(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)) 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. Alternately, 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. 

(f) This amendment becomes effective on February 23, 2000. 

Issued in Burlington, Massachusetts, on January 6, 2000. 

Mark C. Fulmer, 

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

[FR Doc. 00-1193 Filed 1-18-00; 8:45 am] 

BILLING CODE 4910-13-P