Airworthiness Directive 2021-05-19

one-time
Official AD 2021-05-19 · FR doc 2021-06779 · 2021-04-02 · airframe

Airworthiness Directives; Sikorsky Aircraft and Sikorsky Aircraft Corporation Helicopters

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for Sikorsky Aircraft Model S-61L, S-61N, S-61NM, and S-61R helicopters and Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, and S-61V restricted category helicopters. This AD was prompted by the manufacturer determining that there may be arm assemblies in service that have accumulated 15,000 or more hours time-in-service (TIS), which exceeds the service life limit for this component. This AD requires reviewing the mixer unit component log card or equivalent record and, depending on the number of hours TIS, calculating the remaining life of the arm assembly or removing the arm assembly from service. The FAA is issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2021-05-19 applies to

MakesSikorsky AircraftSikorsky Aircraft Corporation
ModelsS-61L, S-61N, S-61NM, S-61R, S-61A, S-61D, S-61E, S-61V, S-61
Part-conditionalS6140-62614-009.

Applies to helicopters, certificated in any category including restricted, with an arm assembly P/N S6140-62614-009 installed.

Whether AD 2021-05-19 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 complianceThe specific action taken (inspected, replaced, modified) and to what revision.
DateWhen the work was done.
Aircraft timeTotal time in service / tach at compliance — how recurring next-due is computed.
Signature & certificateThe A&P/IA who returned it to service, with certificate number.
Is AD 2021-05-19 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.