What two signals must a pilot adhere to during operations?

The correct response focuses on the crucial operational signals that ensure the safety and coordination between the pilot and ground personnel. The signals "wave off" and "hold" are essential for maintaining safety during takeoff and emergency situations.

The "wave off" signal indicates that the pilot should abort the takeoff or landing process and safely maneuver the aircraft away from the runway or landing zone. This signal is vital during instances where the situation is unsafe or if there is an obstruction on the runway that the pilot needs to avoid.

On the other hand, the "hold" signal instructs the pilot to maintain their current position, whether in the air or on the ground. This is particularly important when ground control is managing the flow of air traffic or when conditions require the aircraft to wait before taking further actions.

These signals are fundamental in aviation operations, ensuring clear communication and action between the cockpit and ground personnel, which directly contributes to the safety and efficiency of flight operations.