Airworthiness Directive 2021-04-13

recurring
Official AD 2021-04-13 · FR doc 2021-04806 · 2021-03-10 · airframe

Airworthiness Directives; Airbus Helicopters

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, and AS350D helicopters; Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters; and Model EC130 B4 and EC130 T2 helicopters. This AD requires a one-time inspection to verify the presence and correct installation of the main rotor mast (MRM) upper bearing retaining rings, a repetitive inspection of the sealant bead on the MRM for damage, and corrective actions if necessary. This AD was prompted by a report of a missing retaining ring of the inner race of the MRM upper bearing. The actions of this AD are intended to address an unsafe condition on these products.

Repetitive inspection. Re-inspect every 165 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 2021-04-13 applies to

MakesAirbus Helicopters
ModelsAS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130 B4, EC130 T2, AS350, AS355, EC130

Whether AD 2021-04-13 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 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 2021-04-13 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.