The Turbomeca Arriel is a series of French turboshaft engines that first ran in 1974.Delivering 650 to 1,000 hp (480 to 750 kW), over 12,000 Arriel engines have been produced from 1978 to 2018, logging more than 50 million flight hours for 40 helicopter applications.In June 2018, 1,000 Arriel 2D were in service, powering H125 and H130 single-engine helicopters, having logged one million flight hours since 2011.After endurance tests and fleet data analysis, their TBO increased by 25% to 5,000 hours and mandatory inspection rose to 15 years with no hourly limit, lowering maintenance costs.