AD 86-23-03

86-23-03 PRATT & WHITNEY: Amendment 39-5455. Applies to Pratt & Whitney (PW) JT9D-7R4D, D1, E, and E1 turbofan engines.

Compliance is required as indicated, unless already accomplished.

To prevent failure of the second stage high pressure turbine rotor (HPTR) airseal that can cause an uncontained engine failure, accomplish the following:

(a) Remove from service, HPTR airseal Part Number (P/N) 5001413-01 or 798916 and replace with HPTR airseal P/N 803673 or 803674, respectively, or rework HPTR airseal P/N 5001413-01 or 798916 in accordance with PW Alert Service Bulletin (ASB) JT9D-7R4-72-318, dated October 25, 1986, or FAA approved equivalent, per the following schedule:

(1) JT9D-7R4D1 and JT9D-7R4E1 series engines:

(i) Within 400 cycles in service (CIS) after the effective date of this AD, for HPTR airseals with greater than 800 CIS since new on the effective date of this AD.

(ii) Within 400 CIS after the effective date of this AD, or 800 CIS since new, whichever occurs later, for HPTR airseals with 800 CIS since new or less on the effective date of this AD.

(2) JT9D-7R4D and JT9D-7R4E series engines:

(i) Within 900 CIS after the effective date of this AD, for HPTR airseals with greater than 1,600 CIS since new on the effective date of this AD.

(ii) Within 900 CIS after the effective date of this AD, or 1,600 CIS since new, whichever occurs later, for HPTR airseals with 1,600 CIS since new or less on the effective date of this AD.

(b) Remove first stage high pressure turbine cooling (HPTC) airduct assembly, P/N 796123, 796975, or 796746, and replace with HPTC airduct assembly, P/N 804146, 804145, or 804148, respectively, or rework HPTC airduct assembly, P/N 796123, 796975, or 796746, in accordance with PW ASB JT9D-7R4-72-318, dated October 25, 1986, or FAA approved equivalent, concurrent with accomplishing paragraph (a) above.

(c) Modify the first stage turbine rotor assembly, P/N 792041, 792931,795121, or 801821, by removing two units each of bolt, P/N 746130; washer, P/N 151178; and nut, P/N 341859; and redistributing the remaining units in accordance with PW ASB JT9D-7R4-72-318, dated October 25, 1986, or FAA approved equivalent, concurrent with accomplishing paragraph (a) above.

Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished.

Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine Certification Office, Aircraft Certification Division, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803.

Upon submission of substantiating data by an owner or operator through an FAA maintenance inspector, the Manager, Engine Certification Office, may adjust the compliance times specified in this AD.

Pratt & Whitney ASB JT9D-7R4-72-318, dated October 25, 1986, identifiedand described in this document, is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request to Pratt & Whitney, Commercial Products Division, 400 Main Street, East Hartford, Connecticut 06108. This document also may be examined at the Office of the Regional Counsel, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803, Room 311, Rules Docket Number 86-ANE-42, between the hours of 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.

This amendment becomes effective on December 8, 1986.