Is AD 2017-04634 a recurring Airworthiness Directive?

No — AD 2017-04634 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2017-04634 apply to?

AD 2017-04634 applies to Safran Helicopter Engines — models Arriel 2B, Arriel. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2017-04634

one-time

AD 2017-04634 · 2017-03-09 · turboshaft engine

Airworthiness Directives; Safran Helicopter Engines, S.A. Turboshaft Engines

What this AD requires

We are adopting a new airworthiness directive (AD) for all Safran Helicopter Engines, S.A. Arriel 2B turboshaft engines. This AD requires removing any pre-modification (mod) TU 158 hydro-mechanical metering unit (HMU) and replacing with a part eligible for installation. This AD was prompted by a report of an uncommanded in- flight shutdown (IFSD) on a single-engine helicopter, caused by a low returning spring rate of the needle of the HMU. We are issuing this AD to correct the unsafe condition on these products.

Which aircraft AD 2017-04634 applies to

MakesSafran Helicopter Engines

ModelsArriel 2B, Arriel

Applies only to engines with a pre-modification (mod) TU 158 hydro-mechanical metering unit (HMU) installed (i.e., engines that have not yet incorporated mod TU 158).

Whether AD 2017-04634 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 2017-04634 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.