Is AD 2012-12-20 a recurring Airworthiness Directive?

No — AD 2012-12-20 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2012-12-20 apply to?

AD 2012-12-20 applies to Turbomeca S.A. — models Arriel 2C1, Arriel 2C2, Arriel 2S2, Arriel. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2012-12-20

one-time

Official AD 2012-12-20 · FR doc 2012-15182 · 2012-06-21 · turboshaft engine

Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

What this AD requires

We are adopting a new airworthiness directive (AD) for Turbomeca S.A. Arriel 2C1, 2C2, and 2S2 turboshaft engines. This AD requires replacement of affected digital engine control units (DECUs). This AD was prompted by a report of a helicopter experiencing a DECU malfunction during flight. We are issuing this AD to prevent loss of automatic control on one or both engines installed on the same helicopter, which could result in an uncommanded in-flight engine shutdown, forced autorotation landing, or accident.

Which aircraft AD 2012-12-20 applies to

MakesTurbomeca S.A.

ModelsArriel 2C1, Arriel 2C2, Arriel 2S2, Arriel

Applies only when a digital engine control unit (DECU) with a serial number listed in Table 1 of the AD is installed. Listed DECU S/Ns: 529, 558, 560, 655, 696, 869, 878, 939, 983, 1039, 1050, 1052, 1150, 1195, 1208, 1236, 1302, 1304, 1329, 1330, 1350, 1384, 1408, 1412, 1416, 1429, 1430, 1440, 1464, 1468, 1472, 1499, 1508, 1528, 1557, 1558, 1560, 1567, 1578, 1615, 1616, 1656, 1689 (discrete list, not a contiguous range; no DECU part number given in the applicability text).

Whether AD 2012-12-20 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 2012-12-20 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.