What must a pilot do upon arrival over a fix on a specified heading and holding clearance?

Upon arrival over a fix on a specified heading with a holding clearance, the pilot must execute the holding pattern according to the Air Traffic Control (ATC) instructions given in the clearance. This ensures that the pilot adheres to the specific entry and holding instructions provided by ATC for safe and organized air traffic management.

Executing the holding pattern correctly includes considering the defined holding course, the timing for each leg of the hold, and ensuring that the aircraft remains within regulated airspace while waiting for further instructions. This action helps maintain situational awareness and safety, particularly in busy airspace.

Other possible actions like entering the holding pattern immediately or confirming the entrance to ATC may not align with the established procedures. A pilot does not have the discretion to change course before entering the pattern unless specifically instructed by ATC, as this could lead to conflicts with other aircraft or disrupt established holding patterns. Following the holding pattern as directed by ATC is essential for effective communication and operation within controlled airspace.