Magnetic Shape Memory Alloy (MSMA) Flap for Rotorcraft Primary Flight Control

Sponsored by: U.S. Army Aviation and Missile Command
Team Members: University of Maryland, The Boeing Company

Flight control devices have characteristically been some of the most complex, precise, and flight-critical devices on a helicopter. They generally possess exposed linkages, bearings, swashplate, push rods, and hinges. These components are maintenance intensive, inspection critical, and costly, and they act as a significant source of drag.

Based on our experience in smart rotor development for rotor control and vibration/noise reduction, AITHER and the University of Maryland at College Park (UMD) systematically analyzed the feasibility and actuator requirements for performing primary flight control using an integrated flap system. The results of this analysis demonstrated the feasibility of such an approach while requiring only modest actuator deflections.

To design a suitable actuator, Magnetic Shape Memory Alloy (MSMA) materials were investigated for their high-force, high-displacement properties. Compared to conventional SMA materials that are activated by temperature and phase changes, the magnetically-actuated MSMA materials are capable of achieving much higher frequencies, making them suitable for the dynamic flight control application.