Trim is defined as?

• A. To increase lift
• B. To adjust the aerodynamic forces on the control surfaces so that the aircraft maintains the set attitude without any control input
• C. To decrease drag
• D. To change engine power

Answer: (B)

Trim is the adjustment of a control surface so the airplane holds a desired attitude without the pilot applying continuous control input. By setting the elevator (or other surfaces) via a trim device, the aircraft’s aerodynamic forces are balanced around the center of gravity, producing a steady pitch moment that lets the airplane stay level or maintain a set attitude with no constant stick pressure. This reduces pilot workload and helps keep flight smooth, especially in cruise or during climbs and descents where tiny changes in lift, weight, or thrust would otherwise require constant input. While trim can influence overall drag or lift due to the surface position, its primary purpose is to establish that neutral or steady moment, not to directly increase lift or decrease drag, and it does not change engine power.