Is AD 2020-21-15 a recurring Airworthiness Directive?

No — AD 2020-21-15 is a one-time directive. Verify it was complied with in the aircraft's records.

Airworthiness Directive 2020-21-15

Q: Which aircraft does AD 2020-21-15 apply to?

AD 2020-21-15 applies to Airbus Helicopters — models AS-365N2, AS-365N3, EC155B, EC155B1, SA-365N1, AS-365, EC155, SA-365. Serial/part conditions may narrow it to specific aircraft.

one-time

Official AD 2020-21-15 · FR doc 2020-23977 · 2020-11-02 · airframe

Airworthiness Directives; Airbus Helicopters

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, and SA- 365N1 helicopters. This AD requires inspecting the tail rotor gearbox (TGB) housing recess, and depending on the inspection results, performing more in-depth inspections and removing certain parts from service. This AD also prohibits installing a TGB unless it has passed certain inspections and has a new TGB control rod bearing installed. This AD was prompted by the discovery of a foreign object obstructing the oil duct of a TGB control bearing. The actions of this AD are intended to address an unsafe condition on these products.

Which aircraft AD 2020-21-15 applies to

MakesAirbus Helicopters

ModelsAS-365N2, AS-365N3, EC155B, EC155B1, SA-365N1, AS-365, EC155, SA-365

Whether AD 2020-21-15 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 2020-21-15 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.