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2004-20-04: Compressor rear hubs

FAA order 2004-20-04 is an airworthiness directive in force since October 18, 2004. The FAA's subject line: Compressor rear hubs. It names the Pratt & Whitney Canada PT6B-36A, Pratt & Whitney Canada PT6B-36B engines: about 7 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: engine.

What it applies to as the FAA lists it

Kind of product: Engine
Makes: Pratt & Whitney Canada Corp.
Models: PT6B-36A, PT6B-36B
Engine series: Pratt & Whitney Canada PT6B-36A 3 aircraft
Pratt & Whitney Canada PT6B-36B 4 aircraft

Dates and paperwork

In force since: October 18, 2004
Published: October 1, 2004 (signed September 24, 2004)
Docket: FAA-2004-19170
Status: Current
The FAA's document: Read the order on the FAA's site

The FAA's summary their words, unchanged

The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney Canada (PWC) PT6B-36A and PT6B-36B turboshaft engines with compressor rear hubs, part number (P/N) 3018111 installed. This AD requires reviewing, and correcting if necessary the critical part record for compressor rear hubs, P/N 3018111. This AD also requires removing compressor rear hubs from service that exceed the published part life limit, before further flight. This AD results from the discovery of a compressor rear hub, P/N 3018111, that exceeded the published life limit. This occurred because the operator used an incorrect life limit calculation contained in a PWC Service Bulletin. We are issuing this AD to prevent uncontained failure of the compressor rear hub and damage to the airplane.

The order itself the regulatory text, as published

Show the full text (3,238 characters)

2004-20-04 Pratt & Whitney Canada: Amendment 39-13809. Docket No. FAA-2004-19170; Directorate Identifier 2004-NE-18-AD. 

Effective Date 

	(a) This AD becomes effective October 18, 2004. 

Affected ADs 

	(b) None. 

Applicability 

	(c) This AD applies to Pratt & Whitney Canada (PWC) PT6B-36A and PT6B-36B turboshaft engines with compressor rear hubs, part number (P/N) 3018111 installed. These engines are installed on, but not limited to, Sikorsky S-76B helicopters. 

Unsafe Condition 

	(d) This AD results from results from the discovery of a compressor rear hub, P/N 3018111, that exceeded the published life limit. This occurred because the operator used an incorrect life limit calculation contained in a PWC Service Bulletin. We are issuing this AD to prevent uncontained failure of the compressor rear hub and damage to the helicopter. 

Compliance 

	(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. 

	(f) Within 30 days or at the next engine shop visit, whichever occurs first after the effective date of this AD, do the following: 

	(1) Using the Flight Count Factor of 3, review and correct the critical part record for compressor rear hubs, P/N 3018111. Use paragraph 3 of the Accomplishment Instructions of PWC Service Bulletin (SB) No. PT6B-72-11002, Revision 8, dated June 11, 2003, to do this. 

	(2) Remove the compressor rear hub from service before further flight, if its life limit is found to be at or higher than the published life limit in PWC SB No. PT6B-72-11002, Revision 8, dated June 11, 2003. 

Alternative Methods of Compliance 

	(g) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. 

Special Flight Permits 

	(h) Under 14 CFR part 39.23, we are limiting the special flight permits for thisAD by allowing the engine to operate an additional 25 cycles-in-service or 25 operating hours, whichever occurs first, for moving the helicopter to a location where the requirements of this AD can be done. 

Material Incorporated by Reference 

	(i) You must use Pratt & Whitney Canada Service Bulletin No. PT6B-72-11002, Revision 8, dated June 11, 2003, to perform the reviews and corrections required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You can get a copy from Pratt & Whitney Canada, 1000 Marie- Victorin, Longueuil, Quebec, Canada J4G1A1. You may review copies at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-001, on the Internet at http://dms.dot.gov; or at the 

National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_ register/code_of_federal_regulations/ibr_locations.html. 

Related Information 

	(j) Transport Canada airworthiness directive CF-2003-16, dated June 27, 2003, also addresses the subject of this AD.

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 5, 2026. Connections as data: /graph/directive/2004-20-04.json · aircraft systems.