Airworthiness Directives; Pratt & Whitney JT8D-200 Series Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Pratt & Whitney JT8D-200 series turbofan engines, that currently requires revisions to the Time Limits Section (TLS) of the JT8D-200 Turbofan Engine Manual to include required enhanced inspection of selected critical life-limited parts at each piece-part exposure. This AD adds additional critical life-limited parts for enhanced inspection. This AD is prompted by additional focused inspection procedures that have been developed by the manufacturer. The actions specified by this AD are intended to prevent the failure of critical, life-limited, rotating engine parts, which could result in an uncontained engine failure and damage to the airplane.

DATES:

Effective date December 30, 2002.

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:

Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone 781-238-7175, fax 781-238-7199.

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 2000-21-07, Amendment 39-11939, which is applicable to Pratt & Whitney (PW) JT8D-200 turbofan engines, was published in the Federal Register on October 24, 2000 (65 FR 63540) to require revisions to the Time Limits Section (TLS) of the PW JT8D-200 series Turbofan Engine Manual 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 comments received.

Removal of HPT Assembly Inspection From AD

One commenter suggests that the HPT assembly inspection be removed from the AD because the part is not at piece part level and the prototype cleaning procedures are inadequate. The FAA disagrees. After assembly at manufacture, the HPT disk and shaft essentially can be treated as a single part. The HPT disk and shaft are not required to be separated at overhaul unless there is unrepairable damage to one of the parts or one of the parts has reached a time limit. Further, separation of the parts can cause mechanical damage to the tie rod holes that requires additional repair. The FAA does not want to force the separation of the disk and shaft at every overhaul but does want to have the HPT disk inspected at each opportunity throughout the life of the disk. Therefore, in order to provide a sufficient number of opportunity inspections over the life of the HPT disk, the original equipment manager (OEM) developed an inspection of the disk and shaft assembly. Further, the OEM has addressed problems associated with the prototype process in the final approved inspection process for the disk and shaft assembly. Accordingly, this AD requires changes to the life-limits section that incorporate that inspection of the disk and shaft assembly.

Publication of NPRM

One commenter objects to the publication of the NPRM prior to having the inspection procedure available in the Engine Manual. The commenter states that air carriers that use the affected engines may not have had an opportunity to comment on the inspection procedure. The FAA disagrees. The FAA believes that the nature and scope of the added inspections will not differ significantly from existing inspection procedures. In addition, the FAA has set the effective date of this AD at 180 days after publication to allow time for the manufacturer to include these specific inspection procedures in the next revision of the Engine Manual. Operators may submit additional comments on those inspection procedures and the FAA will consider either extending the effective date further or additional rulemaking, as necessary. The FAA does not believe, however, that this final rule need be delayed pending publication of the inspection procedures.

Effective Date of AD

One commenter requests a 180-day period between the issue date and the effective date of the AD similar to that permitted by the previous rule. The FAA agrees and the effective date of this AD has been extended to 180 days after publication to allow time for the specific procedures to be published. The extra time until the AD becomes effective should allow the manufacturer to issue a manual revision.

Removal of Part Numbers

One commenter believes that the FAA has reversed its position relative to not incorporating part numbers in the AD. The FAA agrees in part. As the commenter notes, the FAA had previously viewed the engine manual for this engine model to be structured so as to make reference to “all” part numbers impractical. The FAA has reviewed the engine manual again and the proposed new changes and determined that individual part numbers may be removed. Therefore, this AD references “all” part numbers, as with other engine lines. The decision not to include part numbers was originally made to accommodate the industry. The removal of part numbers eliminates the requirement to modify the TLS and Continuous Airworthiness Maintenance programs every time a new part number is introduced by the manufacturer for those parts covered by the AD.

Typographical Error

One commenter notes that a typographical error “JT8D/09200,” occurs in paragraphs (a) and (e) of the Compliance Section of the NPRM and should be changed to read “JT8D-200.” The FAA agrees and the change has been made to the rule.

No comments were received on the economic analysis contained in the proposed rule. Based on that analysis, the FAA has determined that the annual per engine cost of $480 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.

2. Section 39.13 is amended by removing Amendment 39-11939 ( 65 FR 63540, October 24, 2000), and by adding a new airworthiness directive, Amendment 39-12797, to read as follows:

AD 2002-13-09 Pratt & Whitney: Amendment 39-12797. Docket No. 98ANE-43AD. Supersedes AD 2000-21-07, Amendment 39-11939.

Applicability: Pratt & Whitney (PW) JT8D-200 series turbofan engines, installed on but not limited to McDonnell Douglas MD-80 series 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 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 Time Limits Section (TLS) of the JT8D-200 Turbofan Engine Manual, and for air carrier operations revise the approved continuous airworthiness maintenance program, by adding the following:

“Critical Life Limited Part Inspection

A. Inspection Requirements:

(1) This section contains 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 is not damaged or related to the cause of its removal from the engine.

(3) The inspections specified in this section do not replace or make unnecessary 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.

(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 using the TLS of the PW JT8D-200 Turbofan Engine Manual.

Alternative Methods 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 Engine Certification Office (ECO). Operators must 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.

Ferry Flights

(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 airplane 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)) must maintain records of the mandatory inspections that result from revising the TLS of the PW JT8D-200 Turbofan Engine Manual, 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 PW JT8D-200 Turbofan Engine Manual.

Effective Date

(f) This amendment becomes effective on December 30, 2002.