Carson Develops New S-61 Tail Rotor
Thierry Dubois for Rotor & Wing International
November 2010
Pennsylvania based Carson Helicopters is developing a composite tailrotor upgrade for the S-61 medium twin. Thanks to a more efficient design the new tailrotor will yield an increased payload at altitude. Speaking at the European Rotorcraft Forum in Paris, company President Frank Carson said the current five bladed rotor lacked efficiency. According to Carson his company’s objective is to design blades which provide increased yaw control at high altitude, using less power while providing a retrofit which does not require any modifications to the aircraft.
With our first blade prototype we failed said Carson as it exhibited “very high control loads.” One reason for this was a mismatch of the inertial properties when compared with the original blade. An additional problem was caused by a minor contour error in the blade mould.
Relative to the original design, the airfoil profile has changed and Carson has introduced an eight degree twist resulting in lower control loads. With material fatigue tests complete Carson hopes to begin flight testing the new blade in November. Carson engineers hope that by requiring less power the new tailrotor will add an additional 300 lbs of lift to the main rotor.
Carson has also exposed the S-61 to an engine upgrade replacing the CT-58-140-1/2 with the T58-GE-16 boosting engine power from 1,400 to 1,870 hp.