US 11,718,390 B2
Propulsion systems for rotorcraft
Eric A. Sinusas, Euless, TX (US); Erik John Oltheten, Fort Worth, TX (US); and Carlos Alexander Fenny, Fort Worth, TX (US)
Assigned to Textron Innovations Inc., Providence, RI (US)
Filed by Textron Innovations Inc., Providence, RI (US)
Filed on Oct. 21, 2020, as Appl. No. 17/76,399.
Application 17/076,399 is a continuation of application No. 15/909,246, filed on Mar. 1, 2018, abandoned.
Prior Publication US 2021/0031908 A1, Feb. 4, 2021
Int. Cl. B64C 27/08 (2023.01); B64C 27/20 (2023.01); B64C 27/82 (2006.01); B64C 27/00 (2006.01)
CPC B64C 27/08 (2013.01) [B64C 27/00 (2013.01); B64C 27/20 (2013.01); B64C 27/82 (2013.01); B64C 2027/8281 (2013.01)] 20 Claims
OG exemplary drawing
 
14. A rotorcraft comprising:
a fuselage;
a tailboom extending from the fuselage;
a tail rotor rotatably coupled to an aft portion of the tailboom and configured to provide yaw control for the rotorcraft; and
a propulsion system coupled to the fuselage, the propulsion system comprising:
a first fan assembly including a central fan and a mast, the central fan including a plurality of first fan blades;
a plurality of second fan assemblies each including a plurality of second fan blades, the second fan assemblies radially symmetric about the mast of the central fan assembly; and
a drive system adapted to provide torque to the first and second fan blades;
wherein, the first fan blades have a larger rotational inertia than the second fan blades;
wherein, the central fan forms a rotor disk and the second fan assemblies are disposed outboard of the rotor disk of the central fan;
wherein, the second fan blades are formed from a different and lighter material than the first fan blades; and
wherein, the second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the drive system, thereby providing responsive thrust control for the rotorcraft.