Is AD 2021-16-13 a recurring Airworthiness Directive?

Yes — AD 2021-16-13 requires a repetitive inspection every 100 hours. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2021-16-13 apply to?

AD 2021-16-13 applies to Leonardo S.P.A. — models A109S, AW109SP, A109. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-16-13

recurring

Official AD 2021-16-13 · FR doc 2021-17605 · 2021-08-18 · 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. (Leonardo) Model A109S and AW109SP helicopters with a certain part-numbered vertical fin vibration absorber installation installed. This AD requires repetitive inspections of the vertical fin vibration absorber installation and the surrounding structure and depending on the inspection results, removing certain parts from service. This AD also prohibits installing certain part-numbered vertical fin vibration absorber installations on any helicopter. This AD was prompted by a report of cracks and damage detected on the vertical fin absorber installation and surrounding structure during scheduled inspections. The FAA is issuing this AD to address the unsafe condition on these products.

Repetitive inspection. Re-inspect every 100 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 2021-16-13 applies to

MakesLeonardo S.P.A.

ModelsA109S, AW109SP, A109

Part-conditional — 109-B810-79-101.

Applies only to helicopters with vertical fin vibration absorber installation P/N 109-B810-79-101 installed.

Whether AD 2021-16-13 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 2021-16-13 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.