Is AD 2004-20-04 a recurring Airworthiness Directive?

No — AD 2004-20-04 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2004-20-04 apply to?

AD 2004-20-04 applies to Pratt & Whitney Canada — models PT6B-36A, PT6B-36B, PT6B. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2004-20-04

one-time

Official AD 2004-20-04 · FR doc 04-21913 · 2004-10-01 · turboshaft engine

Airworthiness Directives; Pratt & Whitney Canada PT6B-36A and PT6B-36B Turboshaft Engines

What this AD requires

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.

Which aircraft AD 2004-20-04 applies to

MakesPratt & Whitney Canada

ModelsPT6B-36A, PT6B-36B, PT6B

Part-conditional — 3018111.

Applies only to engines with compressor rear hub P/N 3018111 installed.

Whether AD 2004-20-04 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.

How AD compliance is recorded

A valid compliance record (14 CFR 43.9) states:

Method of compliance — The specific action taken (inspected, replaced, modified) and to what revision.

Date — When the work was done.

Aircraft time — Total time in service / tach at compliance — how recurring next-due is computed.

Signature & certificate — The A&P/IA who returned it to service, with certificate number.

Is AD 2004-20-04 complied with on your aircraft?

Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.

Look up a tail number →Read the full directive (Federal Register)

Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.