Is AD 2001-20-01 a recurring Airworthiness Directive?

Yes — AD 2001-20-01 requires a repetitive inspection. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2001-20-01 apply to?

AD 2001-20-01 applies to Pratt & Whitney Canada — models PT6A-114A, PT6A-25C, PT6A. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2001-20-01

recurring

Official AD 2001-20-01 · FR doc 01-24270 · 2001-10-01 · turboprop engine

Airworthiness Directives; Pratt & Whitney Canada PT6A-25C and -114A Series Turboprop Engines

What this AD requires

This amendment adopts a new airworthiness directive (AD), applicable to Pratt & Whitney Canada (PWC) PT6A-25C and -114A turboprop engines. This amendment will require initial and repetitive visual inspections, and eventual replacement of the compressor bleed valve assembly, with a redesigned valve assembly for -114A and -25C engines. This amendment is prompted by reports of two occurrences of uncommanded engine power loss. The actions specified by this AD are intended to detect wear in the compressor bleed valve assembly which may cause valve orifice blockage, resulting in a loss of power, an inability to accelerate the engine, and an in-flight shutdown.

Repetitive inspection. Re-inspect. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2001-20-01 applies to

MakesPratt & Whitney Canada

ModelsPT6A-114A, PT6A-25C, PT6A

Applies to PT6A-114A and PT6A-25C series turboprop engines with compressor bleed valve assembly (per PWC SB PT6A-72-1574 Rev 2); replacement of the valve assembly with a redesigned assembly per PWC SB PT6A-72-1588/1581/1589 is terminating action for the repetitive inspections.

Whether AD 2001-20-01 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 2001-20-01 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.