Airworthiness Directive 2018-16652
one-timeAirworthiness Directives; Safran Helicopter Engines, S.A., Turboshaft Engines
What this AD requires
We are superseding Airworthiness Directive (AD) 2012-03-11 for all Safran Helicopter Engines, S.A., Arriel 2B and 2B1 turboshaft engines. AD 2012-03-11 required checking the transmissible torque between the low-pressure (LP) pump impeller and the high-pressure (HP) pump shaft on the HP/LP pump and metering valve assembly, hereafter referred to as the hydro-mechanical metering unit (HMU). Since we issued AD 2012-03-11, the manufacturer determined that incorporating Modification TU 178 is a more effective method to reduce the risk of uncoupling between the LP fuel pump impeller and the HP fuel pump shaft than the prior Modification TU 147. This AD requires inspection and possible replacement of the HMU. This AD was prompted by three cases of uncoupling of the HMU LP fuel pump impeller and the HP fuel pump shaft since AD 2012-03-11 was issued. We are issuing this AD to address the unsafe condition on these products.
Which aircraft AD 2018-16652 applies to
Excludes engines incorporating Modification TU 178.
Whether AD 2018-16652 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
Supersession
Supersedes AD 2012-03-11.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
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.