Is AD 97-21-01 a recurring Airworthiness Directive?

Yes — AD 97-21-01 requires a repetitive inspection every 50 hours. Next-due depends on the aircraft's time in service.

Which aircraft does AD 97-21-01 apply to?

AD 97-21-01 applies to Mt-Propeller Entwicklung Gmbh — models MTV-3-B-C/L250-21, MTV-3. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 97-21-01

recurring

Official AD 97-21-01 · FR doc 97-26373 · 1997-10-07 · propeller

Airworthiness Directives; MT-Propeller Entwicklung GMBH Model MTV-3-B-C Propellers

What this AD requires

This amendment adopts a new airworthiness directive (AD) that is applicable to MT-Propeller Entwicklung GMBH Model MTV-3-B-C propellers. This action requires initial and repetitive dye penetrant or eddy current inspections for cracks in the propeller hub, and rework of the propeller hub or replacement with a new model propeller hub. This amendment is prompted by reports of cracks in the propeller flange area of the hub detected during overhaul. The actions specified in this AD are intended to prevent propeller hub cracks, which could result in propeller blade separation and possible loss of control of the aircraft.

Repetitive inspection. Re-inspect every 50 hours. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 97-21-01 applies to

MakesMt-Propeller Entwicklung Gmbh

ModelsMTV-3-B-C/L250-21, MTV-3

Whether AD 97-21-01 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 97-21-01 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.