# AD 85-19-51 R1: Second Stage Turbine Disk - Type: Airworthiness directive - Status: Current - Products: Pratt & Whitney Division JT8D-15, JT8D-17 and JT8D-17R - Effective: December 26, 1985 - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-5168 - Registered aircraft: 101 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/18EFD680C311E91E8625685F0070D033.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/85-19-51-R1 ## The airworthiness directive 85-19-51 R1 PRATT & WHITNEY AIRCRAFT: Amendment 39-5168. Applies to Pratt and Whitney Aircraft JT8D-15, -17, and -17R turbofan engines. Compliance is required as indicated unless already accomplished. To prevent possible failure of the second stage turbine disk, inspect second stage turbine disk, Part Numbers 676802, 770602, 780502, 786802, and 787302 details, and Part Numbers 676822, 769722, 769832, 786822, and 787232 assemblies for wear and cracking of the snap diameter and at the bottom of the disk airseal groove, repair the disk, and modify the mating third stage turbine inner airseal in accordance with the Accomplishment Instructions (Paragraph 2) of PWA Alert SB 5541, Revision 1, dated May 4, 1984, and PWA SB 5510, Revision 1, dated February 13, 1984, or FAA approved equivalents, per the following schedule: (a) For disks which have not had the airseal groove previously repaired: (1) With 14,000 hours or more time in service since new - inspect, repair andmodify prior to reaching 17,000 hours time in service since new or within the next 2,000 hours time in service, whichever occurs first. (2) With less than 14,000 hours time in service since new - inspect, repair and modify by 14,000 hours time in service since new or within the next 2,000 hours time in service, whichever occurs later. (b) For disks which have had the airseal groove previously repaired: (1) With 2,000 hours or more time in service since repair - inspect, repair, and modify within the next 400 hours time in service. (2) With less than 2,000 hours time in service since repair, inspect, repair and modify by 2,000 hours time in service since repair or within the next 400 hours time in service, whichever occurs later. Disks worn beyond the repair limits of the applicable SB's must be removed from service. 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 of an owner or operator, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine Certification Office, 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, New England Region, may adjust the compliance schedule specified in this AD. PWA SB Number 5510, Revision 1, dated February 13, 1984, and the Accomplishment Instructions of (Paragraph 2) PWA Alert SB 5541, Revision 1, dated May 4, 1984, are 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 these documents from the manufacturer may obtain copies upon request to Pratt & Whitney Aircraft Group, Commercial Products Division, 400 Main Street, East Hartford, Connecticut 06108.These documents also may be examined at the Office of Regional Counsel, New England Region, FAA, Room No. 311, between the hours of 8:00 a.m. and 4:30 p.m., Monday though Friday except Federal holidays. This amendment supersedes Amendment 39-4879 (49 FR 37568) AD 84-16-03. Those provisions of this amendment which apply to unrepaired disks become effective on December 26, 1985. The remaining provisions of this amendment become effective December 26, 1985, except to those persons to whom they were made immediately effective by individual telegrams issued September 25, 1985. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E2EA](https://openairdocs.org/tcds/E2EA): Pratt & Whitney; names 3 of 16 models: JT8D-17R, JT8D-15, JT8D-17 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 101 (0 by airframe model, 101 by engine model) - Makers: Mcdonnell Douglas 80, Boeing 19, Beech 1, Douglas 1 Models with the most aircraft: - [Pratt & Whitney JT8D series](https://openairdocs.org/engine/pratt-whitney-jt8d-series): 82 aircraft (engine model) - [Pratt & Whitney JT8D-17 series](https://openairdocs.org/engine/pratt-whitney-jt8d-17-series): 7 aircraft (engine model) - [Pratt & Whitney JT8D-17](https://openairdocs.org/engine/pratt-whitney-jt8d-17): 6 aircraft (engine model) - [Pratt & Whitney JT8D-15](https://openairdocs.org/engine/pratt-whitney-jt8d-15): 6 aircraft (engine model) All 4 models: https://openairdocs.org/ad/85-19-51-R1/models.md Every aircraft: https://openairdocs.org/ad/85-19-51-R1/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.