Trim systems belong to which group of flight controls?

• A. Secondary flight controls
• B. Primary flight controls
• C. Aileron
• D. Rudder

Answer: (A)

Trim systems are considered secondary flight controls. They adjust the position of a control surface automatically to balance aerodynamic forces so the pilot doesn’t have to hold constant pressure on the controls. This lets the airplane maintain a chosen condition, like a steady pitch or attitude, with less effort from the pilot. Primary flight controls, by contrast, are the surfaces you actively move to directly change the aircraft’s attitude in real time—these include the main elevator, ailerons, and rudder. The trim system isn’t a single surface like an aileron or rudder; it’s a mechanism (often involving a trim tab or servo) that sets the neutral or preselected position of a surface to ease control and reduce stick force. So the best characterization is that trim is part of the secondary flight controls.