Rudder pedals no longer produce any noticeable change in heading.

• A. Elevator System Jammed
• B. Rudder System Jammed
• C. Stabilizer Trim Runaway
• D. Unreliable Airspeed

Answer: (B)

Rudder control is what changes the aircraft’s heading; if the pedals produce no noticeable change in heading, the rudder itself isn’t moving, indicating a jam or obstruction in the rudder system. This means the yaw authority is effectively lost, so the airplane won’t respond to pedal input the way it should.

Elevator issues would affect pitch rather than heading—an elevator jam would prevent elevator deflection, changing climb/descent or nose-up/nose-down control, not the ability to yaw. A stabilizer trim runaway drives the aircraft’s pitch automatically through trim inputs, which can create control difficulties but doesn’t lock the rudder or prevent heading changes via pedal input. Unreliable airspeed affects the airspeed indicator and performance readings, not the direct ability to change heading with rudder.