Emergency Anti-torque System for Rotary Wing Aircraft (Manned and Unmanned)

Period of Performance: 10/22/2008 - 04/21/2009


Phase 1 SBIR

Recipient Firm

Eatts Research & Development Corp.
17024 Echo Lake Dr.
Smithfield, VA 23430
Principal Investigator


In Phase I, Emergency Anti-Torque Thruster System (EATTS) concepts will be developed to demonstrate that main rotor torque of a rotorcraft can be overcome even after the loss of the primary anti-torque system. Modeling and simulation will demonstrate how uncontrolled yaw caused by tail rotor failure (TRF) and loss of tail rotor effectiveness (LTE) can be surmounted. EATTS utilizes anti-torque thrusters to counteract and neutralize the torque effect in the main rotor system. This technology is universal in rotorcraft application but specific in design for each platform and takes into consideration the differences in power, gross weight, center of gravity, structure, and various other components. EATTS R&D will address thruster activation and control processes, the sensors needed to detect the various causes of TRF and LTE, and their interactions with each other. In Phase II, EATTS R&D will continue development on thruster activation, control processes and TRF sensors and will demonstrate activation of a controlled anti-torque prototype thruster system after disengaging the tail rotor on a fully operating helicopter tethered to a rotating base. In Phase III, EATTS R&D will flight demonstrate a fully functioning thruster system on a helicopter and will continue development and commercialization of EATTS.