02-29670. Airworthiness Directives; Pratt & Whitney JT8D-200 Series Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), that is applicable to Pratt & Whitney (PW) JT8D-200 series turbofan engines. This amendment requires initial and repetitive visual inspections, fluorescent magnetic particle inspections (FMPI), and fretting wear inspections of high pressure compressor (HPC) front hubs that have operated with PWA-110 coating in the interface between the hub and the stage 8-9 spacer. This amendment is prompted by the discovery of cracked tierod holes found during routine engine overhauls. The actions specified by this AD are intended to prevent a rupture of the HPC front hub that could result in an uncontained engine failure and damage to the airplane.

DATES:

Effective December 31, 2002. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of December 31, 2002.

ADDRESSES:

The service information referenced in this AD may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108, telephone [phone]; fax [phone]. This information may be examined, by appointment, at the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Christopher Spinney, 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:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that is applicable to PW JT8D-200 series turbofan engines was published in the Federal Register on September 19, 2002 (67 FR 59027). That action proposed to require initial and repetitive visual inspections, FMPI, and fretting wear inspections of HPC front hubs that have operated with PWA-110 coating in the interface between the hub and the stage 8-9 spacer in accordance with PWAlert Service Bulletin (ASB) JT8D A6430, dated September 5, 2002.

Comments

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

Credit for Inspections

Two commenters request that the AD be changed to allow credit for inspections occurring before 9,000 cycles in service (CIS). One commenter requests that the second inspection occur within 6,500 cycles of the initial inspection, while the other commenter requests that the second inspection occur as late as 18,000 cycles.

The FAA partially agrees. The FAA agrees that some credit should be given for inspections occurring before 9,000. We do not agree, however, that the second inspection should be delayed until 18,000 CIS. A 15,500 CIS limit is more appropriate. Further, the shop visit requirement will be relaxed to an accessibility requirement for HPC front hubs inspected before accumulating 9,000 CIS. Accordingly, the inspection interval for HPC front hubs has been modified for hubs with less than 17,000 CIS to account for hubs inspected before 9,000 CIS. These hubs can be reinspected at the first accessibility of the HPC front hub after accumulating 9,000 CIS but not to exceed 15,500 CIS.

Effective Date To Include Sufficient Time for Alternative Methods of Compliance (AMOC) Request

One commenter requests that the effective date be chosen to allow sufficient time for an AMOC request.

The FAA agrees. The FAA provides a 35-day time frame from the date of publication to the effective date of the AD which should provide sufficient time to request an AMOC, if necessary.

Exclude Engine Buildup Shop From the Shop Visit Requirements

One commenter requests that an LPT module replacement performed at an engine buildup shop be excluded from the shop visit requirements of this AD. The commenter feels that there are a small number of engines affected annually for this particular operator.

The FAA does not agree. The variability of every operator's maintenance program makes it difficult to define a shop visit that meets all operator's needs. The FAA believes the current definition is best suited for all operators. If an individual operator believes some engines should be exempt from the shop visit definition of the AD because of some unique features of their maintenance program, then they should seek approval for that provision in accordance with paragraph (f) of this AD.

Understated Financial Impact

One commenter states that the FAA underestimates the economic impact of the AD by failing to include ancilliary costs of the AD.

The FAA does not agree. The indirect costs associated with this AD are not directly related to this rule, and, therefore, are not addressed in the economic analysis for this rule. A full cost analysis for each AD, including such indirect costs, is not necessary since the FAA has already performed a cost benefit analysis when adopting the airworthiness requirements to which these engines were originally certificated. A finding that an AD is warranted means that the original design no longer achieves the level of safety specified by those airworthiness requirements, and that other required actions are necessary. Because the original level of safety was already determined to be cost beneficial, these additional requirements needed to return the engine to that level of safety do not add any additional regulatory burden, and, therefore, a full cost analysis would be redundant and unnecessary.

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.

Economic Analysis

There are approximately 2,648 PW JT8D-200 series turbofan engines of the affected design in the worldwide fleet. The FAA estimates that 2,352 engines installed on airplanes of U.S. registry would be affected by this AD. The FAA also estimates that it would take approximately 6 work hours per engine to perform the inspection, and that the average labor rate is $60 per work hour. Based on these figures, the total cost of the initial inspection to U.S. operators is estimated to be $846,720.

Regulatory Analysis

This final rule does not have federalism implications, as defined in Executive Order 13132, because it 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this final rule.

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 the 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 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
• Incorporation by reference
• 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

[Amended]

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

2002-23-14 Pratt & Whitney: Amendment 39-12958. Docket No. 2001-NE-30-AD.

Applicability: This airworthiness directive (AD) is applicable to Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219 series turbofan engines that have high pressure compressor (HPC) front hubs installed that have operated with PWA-110 coating in the interface between the HPC front hub and the stage 8-9 spacer (PWA-110 coating applied to either the spacer or the hub) and were manufactured after June 1, 1988. These engines are installed on, but not limited to McDonnell Douglas MD-80 series airplanes.

Note 1:

This 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 (f) 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 a rupture of the HPC front hub, that could result in an uncontained engine failure and damage to the airplane, do the following:

Inspect hubs

(a) Strip the protective coating, visually inspect for fretting wear, fluorescent magnetic particle inspect (FMPI), reidentify and replate HPC front hubs and the stage 8-9 spacers, and replace if necessary in accordance with the accomplishment instructions of Pratt & Whitney Alert Service Bulletin (ASB) JT8D A6430, dated September 5, 2002, as follows:

(1) For HPC front hubs with fewer than 17,000 total cycles-in-service (CIS) on the effective date of this AD, inspect as follows:

(i) For HPC front hubs not inspected in accordance with ASB JT8D A6430, dated September 5, 2002, before accumulating 9,000 total CIS, inspect at the first shop visit after accumulating 9,000 total CIS not to exceed 18,000 total CIS.

(ii) For HPC front hubs inspected in accordance with ASB JT8D A6430, dated September 5, 2002, before accumulating 9,000 total CIS, inspect at the next accessibility of the HPC front hub after accumulating 9,000 total CIS not to exceed 15,500 total CIS.

(2) For HPC front hubs with greater than or equal to 17,000 total CIS but less than 19,000 total CIS on the effective date of this AD, inspect at the next shop visit, not to exceed 1,000 CIS from the effective date of this AD or 19,500 total CIS, whichever occurs first.

(3) For HPC front hubs with greater than or equal to 19,000 total CIS on the effective date of this AD, inspect within 500 CIS from the effective date of this AD.

Repetitive-Inspections

(b) Thereafter, strip the protective coating, visually inspect for fretting wear, FMPI and replate HPC front hubs, and replace if necessary in accordance with the accomplishment instructions of Pratt & Whitney Alert Service Bulletin (ASB) JT8D A6430, dated September 5, 2002, at intervals not to exceed 6,500 CIS since the last inspection.

Optional Terminating Action

(c) Installation of a Nickel-Cadmium plated HPC front hub that has never operated with PWA-110 coating in the interface between the HPC front hub and the stage 8-9 spacer and a Nickel-Cadmium or Electroless Nickel plated spacer is an optional terminating action for the inspections of paragraphs (a) and (b) of this AD.

Definitions

(d) For the purposes of this AD, a shop visit is defined as an engine removal, where engine maintenance entails separation of pairs of major engine flanges or the removal of a disk, hub, or spool at a maintenance facility, regardless of other planned maintenance, except as follows:

(1) Engine removal for the purpose of performing field maintenance type activities at a maintenance facility in lieu of performing them on-wing is not a “shop visit”.

(2) Separation of flanges of the Combustion Chamber and Turbine Fan Duct Assembly (split flanges) for the purpose of accessing non-rotating accessory hardware is not a “shop visit”.

(3) Separation of flanges for the purpose of shipment without subsequent internal maintenance is not a “shop visit”.

(e) For the purposes of this AD accessibility of the HPC front hub is removal of the hub from the engine and deblading of that hub.

Alternative Methods of Compliance

(f) 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

(g) 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.

Documents That Have Been Incorporated By Reference

(h) The inspections must be done in accordance with Pratt & Whitney Alert Service Bulletin (ASB) JT8D A6430, dated September 5, 2002. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108, telephone [phone]; fax [phone]. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(i) This amendment becomes effective on December 31, 2002.

Issued in Burlington, Massachusetts, on November 15, 2002.

Mark C. Fulmer,

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