Is AD 2021-23-17 a recurring Airworthiness Directive?

No — AD 2021-23-17 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2021-23-17 apply to?

AD 2021-23-17 applies to Hoffmann Gmbh & Co. Kg — models HO-V 72. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-23-17

one-time

Official AD 2021-23-17 · FR doc 2021-26365 · 2021-12-06 · propeller

Airworthiness Directives; Hoffmann GmbH & Co. KG Propellers

What this AD requires

The FAA is superseding Airworthiness Directive (AD) 2020-25-05 for all Hoffmann GmbH & Co. KG (Hoffmann) model HO-V 72 propellers. AD 2020-25-05 required amending the existing aircraft flight manual (AFM) with abnormal propeller vibration instructions. AD 2020-25-05 also required visual inspection and non-destructive test (NDT) inspection of the propeller hub and, depending on the results of the inspections, replacement of the propeller hub with a part eligible for installation. AD 2020-25-05 also required replacement of the propeller hub before exceeding 30 years since the date of manufacture. This AD was prompted by reports of cracks at different positions on two affected propeller hubs and subsequent manufacturer revision of the service information, which showed that the 30-year life limit of the propeller hub is no longer needed. This AD requires amending the existing AFM by inserting abnormal propeller vibration instructions, visual inspection and NDT inspection of the propeller hub and, depending on the results of the inspections, replacement of the propeller hub with a part eligible for installation. The FAA is issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2021-23-17 applies to

MakesHoffmann Gmbh & Co. Kg

ModelsHO-V 72

Whether AD 2021-23-17 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 2021-23-17 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.