Is AD 2021-19253 a recurring Airworthiness Directive?

No — AD 2021-19253 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2021-19253 apply to?

AD 2021-19253 applies to Airbus Helicopters Deutschland Gmbh — models D-2, BK117. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-19253

one-time

AD 2021-19253 · 2021-09-08 · airframe

Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 D-2 helicopters. This AD was prompted by the discovery that certain parts that are approved for installation on multiple helicopter models are life limited parts when installed on Model MBB-BK 117 D-2 helicopters and some helicopter delivery documents excluded the life limit information. This AD requires determining the total hours time-in- service (TIS) of a certain part-numbered rotor mast nut and re- identifying a certain part-numbered rotor mast nut. This AD also requires establishing a life limit for a certain part-numbered rotor mast nut and helical gear support, and removing each part from service before reaching its life limit. Additionally, this AD requires replacing a certain part-numbered main gearbox (MGB) with a not affected MGB as specified in a European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) AD, which is incorporated by reference (IBR). The FAA is issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2021-19253 applies to

MakesAirbus Helicopters Deutschland Gmbh

ModelsD-2, BK117

Applies only to helicopters with an affected main gearbox or affected rotor mast nut as identified in Note 1 of EASA AD 2017-0037, dated February 22, 2017, installed.

Whether AD 2021-19253 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 2021-19253 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.