The nosewheel steering system is electronically controlled and hydraulically actuated. Which statement best describes steer-by-wire?

• A. Electronically controlled; hydraulically actuated
• B. Mechanically controlled; hydraulically actuated
• C. Electrically powered; mechanically linked
• D. Hydraulically controlled; electrically driven

Answer: (A)

Steer-by-wire replaces a direct mechanical linkage with an electronic sensing and control path that commands hydraulic movement. In this nosewheel system, the pilot’s steering input is captured and converted into electronic signals, processed by control electronics, and then hydraulic actuators move the nose gear to the commanded angle. That combination—electronic control of the command and hydraulic actuation of the movement—best matches steer-by-wire.

If the system were mechanically controlled, there would be a direct physical connection from the steering input to the nose gear, which steer-by-wire eliminates. If it were electrically powered but mechanically linked, the motion would still flow through a physical linkage, defeating the steer-by-wire concept. If it were hydraulically controlled and electrically driven, the control path and actuation roles would be inverted relative to the steer-by-wire model, not reflecting the primary electronic command leading to hydraulic actuation.