US Patent 10933990 Modal tailboom flight control systems for compound helicopters

A modal tailboom flight control system for a compound helicopter is operable in a plurality of modes including a forward thrust mode and an anti-torque mode. The modal tailboom flight control system includes a tailboom, a drivetrain extending through the tailboom, an anti-torque system coupled to the drivetrain and rotatable to generate anti-torque thrust for the compound helicopter in the anti-torque mode and a pusher propeller coupled to the drivetrain and rotatable to generate forward thrust for the compound helicopter in the forward thrust mode. The pusher propeller is positioned forward of the anti-torque system.