Is AD 2021-10-18 a recurring Airworthiness Directive?

No — AD 2021-10-18 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2021-10-18 apply to?

AD 2021-10-18 applies to Airbus Helicopters Deutschland Gmbh — models MBB-BK117 D-2, MBB-BK117. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-10-18

one-time

Official AD 2021-10-18 · FR doc 2021-11391 · 2021-06-01 · airframe

Airworthiness Directives; Airbus Helicopters Deutschland GmbH Helicopters

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Helicopters Deutschland GmbH Model MBB-BK117 D-2 helicopters. This AD was prompted by reports that collective lever switch units having certain part numbers did not have retaining rings installed in the cable cut switch guard. This AD requires inspecting certain collective lever switch units for discrepancies (missing retaining rings, incorrectly installed retaining rings, and a missing axis in the cable cut switch guard), doing all applicable corrective actions, and marking affected parts, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2021-10-18 applies to

MakesAirbus Helicopters Deutschland Gmbh

ModelsMBB-BK117 D-2, MBB-BK117

Applies to all serial numbers having an affected part defined in European Union Aviation Safety Agency (EASA) AD 2020-0084, dated April 3, 2020 (EASA AD 2020-0084).

Whether AD 2021-10-18 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 2021-10-18 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.