sentences:  It uses an automatically-varying three-bladed Starflex main rotor which is matched to an enclosed tail fan anti-torque device, known as a Fenestron, the latter feature replacing the traditional tail rotor found on the older AS350.The Fenestron has unevenly spaced blades to reduce noise generation by 50% compared to a tail rotor; this enabled an FAA Appendix H fly-over noise signature of 84.3 EPNdB, 8.5 dB below stage two limits.The EC130 uses the Turbomeca Arriel 2D turboshaft engine; the performance of this powerplant has led to the type having been described as possessing "better power margins and range than competing models, particularly in hot and high conditions".