AD 2003-16-05

This amendment adopts a new airworthiness directive (AD) that applies to Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219 series turbofan engines. This amendment requires removal and replacement of protective coating of the 7th and 9th through 12th stage high pressure compressor (HPC) disks and the 8th stage HPC hub, initial and repetitive inspections for corrosion pits and cracks, and removal from service as required. This amendment is prompted by reports from operators of cracks observed in JT8D engine steel HPC disks. We are issuing this AD to prevent fracture of the 7th and 9th through 12th stage HPC disks and 8th stage HPC hub, resulting in uncontained engine failure and damage to the airplane.

Final rule.

2003-16-05 Pratt & Whitney: Amendment 39-13258. Docket No. 2002-NE- 41-AD.

Applicability: This airworthiness directive (AD) applies to Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219 series turbofan engines. 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 (d) 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: You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

To prevent fracture of the 7th and 9th through 12th stage high pressure compressor (HPC) disks and 8th stage HPC hub, resulting in uncontained engine failure and damage to the airplane, do the following:

(a) Perform initial and repetitive inspections of 7th and 9th through 12th stage HPC disks and 8th stage HPC hubs for corrosion pits and cracks after stripping the protective coating in accordance with the intervals specified in the compliance section and procedures specified in the accomplishment instructions of PW alert service bulletin (ASB) JT8D A6435, Revision 1, dated March 7, 2003.

(b) Before further flight, replace 7th and 9th through 12th stage HPC disks and 8th stage HPC hubs found with corrosion pits or cracks beyond serviceable limits as defined by PW ASB JT8D A6435, Revision 1, dated March 7, 2003.

(c) For the purposes of this AD, use the effective date of this AD for computing compliance intervals whenever PW ASB JT8D A6435, Revision 1, dated March 7, 2003, refers to the release date of the ASB.

Alternative Methods of Compliance

(d) 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 request 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

(e) Special flight permits may be issued in accordance with 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and21.199) to operate the airplane to a location where the requirements of this AD can be done.

Documents That Have Been Incorporated by Reference

(f) The actions must be done in accordance with Pratt & Whitney alert service bulletin JT8D A6435, Revision 1, dated March 7, 2003. 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 (860) 565-8770; fax (860) 565-4503. 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

(g) This amendment becomes effective on September 12, 2003.

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-209, -217, -217A, -217C, and -219 series turbofan engines was published in the Federal Register on March 25, 2003 (68 FR 14351). That action proposed to require removal and replacement of protective coating of the 7th and 9th through 12th stage HPC disks and the 8th stage HPC hub, initial and repetitive inspections for corrosion pits and cracks, and removal from service as required in accordance with PW alert service bulletin (ASB) JT8D A6435, Revision 1, dated March 7, 2003.

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.

Disk Tracking

One commenter requests that the disks inspected using PW ASB JT8D 6435, Revision 1, dated March 7, 2003, as well as all new disks, be tracked by the engine releasedate recorded on FAA 337 form or equivalent rather than per individual disk inspection dates. The commenter feels that this would significantly reduce the burden on airline records departments, especially for large operators, because the time between the disk inspection and the engine release date is typically not more than a few weeks.

The FAA does not agree. There is no way to ensure that the time between the disk inspection and the engine release date will always be a short or controlled amount of time. Some operators or repair facilities may elect to store disks in their inventory for long periods of time. Unless these disks are preserved using instructions in the ASB, the time in storage must be counted in the accumulation of time to the next inspection because the corrosion protective coatings begin to degrade while in storage without proper preservation. However, if an operator can show that their particular operation will always result in short controlled times between inspection and installation and can demonstrate that an acceptable level of safety is maintained, they may apply for relief in accordance with paragraph (d) of this AD.

After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

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: