Trim is a secondary flight control system that incorporates small tabs on the ailerons, the rudder, and, most commonly, on ...

However without anyone in control, the ailerons, elevators and rudder lock ... can manually trim the plane if the RAT is activated, providing enough power to allow basic flight controls to function.

Aviation safety authorities said the plane's rudder trim had been in the wrong position, causing the crash. The problem should have been detected in pre-flight checks, they said. Passengers Greg ...