# AD 78-17-02 R3: Compressor Front Hubs - Type: Airworthiness directive - Status: Current - Products: Pratt & Whitney Division JT8D-11, JT8D-15, JT8D-15A, JT8D-17, JT8D-17A, JT8D-17AR, JT8D-17R, JT8D-9 and JT8D-9A - Effective: March 30, 1984 - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-4818 - Registered aircraft: 118 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6224C0815A0A1DFB8625685E0072C199.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/78-17-02-R3 ## The airworthiness directive 78-17-02 R3 PRATT & WHITNEY AIRCRAFT: Amendment 39-3281 as amended by Amendment 39-4334 and 39-4407 is further amended by Amendment 39-4818. Applies to Pratt & Whitney Aircraft models JT8D-9, - 9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines. Compliance is required as indicated, unless already accomplished. To detect cracks in compressor front hubs, P/Ns 594301, 791801, 640601, 743301, 750101, and 749801, except those excluded by serial number in Pratt & Whitney Aircraft Alert Service Bulletin No. 4841, Revision 6, dated July 15, 1983, which could result in fracture of the retention lugs and release of first stage fan blades, accomplish the following: (A) Inspect front compressor front hubs for cracks in the blade slots in accordance with Pratt & Whitney Aircraft Alert Service Bulletin No. 4841, Revision 6, dated July 15, 1983, or equivalent means approved by the Manager, Engine Certification Branch, New England Region, and in accordance with limits specified in Paragraphs (B) and (C) of this AD. Remove cracked compressor front hubs prior to further flight. (B) Hubs not previously inspected shall be inspected within 1,000 cycles from the effective date of this AD or before reaching the initial inspection limits specified in Column I of Paragraph (D), whichever occurs later, except do not exceed 13,000 total cycles. Repeat inspections at intervals listed in Column II, or Column III, Paragraph (D), thereafter. (C) Hubs which have been previously inspected shall be reinspected within 1,000 cycles after the effective date of this AD or before reaching the initial inspection limit specified in Column I, Paragraph (D), or before reaching the repetitive inspection limits specified in Column II or Column III of Paragraph (D), whichever comes later. Repeat inspections at intervals listed in Column II or Column III, Paragraph (D), thereafter. (D) Model Column I, initial inspection limit (cycles) Column II, Eddy current repetitive inspection limit (cycles) Column III, on-wing ultrasonic repetitive repetitive inspection limit (cycles) JT8D-9, -9A 13,000 6,000 2,000 JT8D-11 10,500 6,000 2,000 JT8D-15, -15A 9,500 5,000 1,500 JT8D-17, -17A 8,500 5,000 1,500 JT8D-17R, -17AR 8,000 5,000 1,500 NOTE: If the initial inspection or repetitive inspection is in paragraph (D) apply. If, however, the initial inspection or repetitive inspection is achieved by an eddy current inspection on an uninstalled engine, the Column II inspection limits of paragraph (D) would apply. (E) Upon request of the operator, an FAA maintenance inspector, subject to the approval of the Manager, Engine Certification Branch, FAA, New England Region, may adjust the inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. (F) For hubs that have been installed in more than one engine model, the inspection schedule for the engine model with the highest thrust rating in which it has operated is applicable. The manufacturer's Alert Service Bulletin identified and described in this directive is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a). All persons affected by this directive who have not already received the service bulletin from the manufacturer may obtain copies upon request to Pratt & Whitney Aircraft, Commercial Products Division, 400 Main Street, East Hartford, Connecticut 06108. The service bulletin may also be examined at Federal Aviation Administration, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, Massachusetts 01803. Amendment 39-3281 became effective September 20, 1978. Amendment 39-4334 became effective March 4, 1982. Amendment 39-4407 became effective June 28, 1982. This Amendment 39-4818 becomes effective March 30, 1984. ## 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 9 of 16 models: JT8D-17AR, JT8D-17R, JT8D-15A, JT8D-15, JT8D-17, JT8D-17A, JT8D-11, JT8D-9… ## 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: 118 (0 by airframe model, 118 by engine model) - Makers: Mcdonnell Douglas 82, Boeing 33, Douglas 2, Beech 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-9 series](https://openairdocs.org/engine/pratt-whitney-jt8d-9-series): 9 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) - [Pratt & Whitney JT8D-9A](https://openairdocs.org/engine/pratt-whitney-jt8d-9a): 5 aircraft (engine model) - [Pratt & Whitney JT8D-9](https://openairdocs.org/engine/pratt-whitney-jt8d-9): 1 aircraft (engine model) - [Pratt & Whitney JT8D-15A](https://openairdocs.org/engine/pratt-whitney-jt8d-15a): 1 aircraft (engine model) - [Pratt & Whitney JT8D-17A](https://openairdocs.org/engine/pratt-whitney-jt8d-17a): 1 aircraft (engine model) All 9 models: https://openairdocs.org/ad/78-17-02-R3/models.md Every aircraft: https://openairdocs.org/ad/78-17-02-R3/aircraft.md Its text cites no advisory circulars or STCs. --- From OpenAirDocs.org, an independent open copy of FAA and NTSB data. Only the Federal Register edition on govinfo.gov is the official legal text of an AD.