Is AD 2017-19-20 a recurring Airworthiness Directive?

No — AD 2017-19-20 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2017-19-20 apply to?

AD 2017-19-20 applies to General Electric Company — models CT7-8A, CT7-9B, CT7. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2017-19-20

one-time

Official AD 2017-19-20 · FR doc 2017-19961 · 2017-09-22 · turboshaft engine

Airworthiness Directives; General Electric Company Turboshaft Engines

What this AD requires

We are adopting a new airworthiness directive (AD) for certain General Electric Company (GE) CT7-8A and CT7-9B model turboshaft engines. This AD was prompted by reports from the manufacturer that the high-pressure compressor (HPC) impeller installed on these engines may have suffered from material degradation during the manufacturing process. This AD requires removal of the affected HPC impellers. We are issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2017-19-20 applies to

MakesGeneral Electric Company

ModelsCT7-8A, CT7-9B, CT7

Part-conditional — 5123T51P02.

Applies only to engines with high-pressure compressor (HPC) impeller P/N 5123T51P02 bearing serial number GLHTPH9G, GLHTPP7P, or GLHTPJHN installed.

Whether AD 2017-19-20 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 2017-19-20 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.