We have pioneered the first application of a Trimmable Horizontal Stabiliser (THSA) ‘smart actuator' for Airbus on the A330/340 it provides a complete system for this the most complicated actuator on an aircraft. The THSA carries out complex computations to trim the aircraft during flight optimising aerodynamic performance.

The horizontal tail of the aircraft is hinged and positioned by the horizontal stabiliser actuator. The actuator slowly moves the surface to trim out any deflection of the elevator in response to trim signals from the pilot or autopilot.

The actuator must have a very high structural integrity and is usually, a dual load path ball screw, driven by electrically or mechanically controlled hydraulic motors.

Smaller aircraft have been using electric rather than hydraulic motors for many years, the advances in motor technology now make it possible to consider electro-mechanical stabiliser actuators for larger aircraft.

• Controls the position of the aircraft horizontal stabiliser surface
• Commands received from aircraft's trim command systems
• Single actuator using dual electric / hydraulic motor drives
• Each drive controlled independently

Open or Closed loop control depending on application