Is AD 2021-17-15 a recurring Airworthiness Directive?

No — AD 2021-17-15 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2021-17-15 apply to?

AD 2021-17-15 applies to Leonardo S.P.A. — models AB139, AW139. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-17-15

one-time

Official AD 2021-17-15 · FR doc 2021-19243 · 2021-09-08 · airframe

Airworthiness Directives; Leonardo S.p.a. Helicopters

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for Leonardo S.p.a. Model AB139 and AW139 helicopters with certain main rotor blades installed. This AD was prompted by a report of an in- flight loss of a main rotor blade (MRB) tip cap. This AD requires inspecting the MRB tip cap for disbonding. The FAA is issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2021-17-15 applies to

MakesLeonardo S.P.A.

ModelsAB139, AW139

Part-conditional — 3G6210A00131.

Applies only to helicopters with a main rotor blade (MRB) having less than 1,200 total hours time-in-service (TIS), part number 3G6210A00131, with any serial number listed in Table 1 of Leonardo Helicopters Alert Service Bulletin No. 139-520, dated April 26, 2018, installed.

Whether AD 2021-17-15 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 2021-17-15 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.