Which statement about residual control forces is true when using a stabilizer trim alternative?

• A. Increases control forces
• B. Has no effect
• C. Reduces residual control forces
• D. Increases drag

Answer: (C)

Using a stabilizer trim alternative means the elevator/stabilizer is set to a trimmed position that counteracts pitch moments, so the pilot doesn’t have to apply as much continuous effort to hold a given attitude. Residual control forces are the remaining forces you must apply on the control wheel to maintain that flight condition after trimming. With the stabilizer trim active, the surface helps balance the aircraft, so the pilot’s continuous input is reduced, lowering the residual control forces. This is why reducing residual control forces is the correct effect. The option isn’t that there’s no effect, nor that forces would be increased; while trim can influence drag, the specific outcome described here is the decrease in the ongoing control effort.