What is the primary purpose of a private pilot certificate?

The primary purpose of a private pilot certificate is to allow the holder to act as pilot-in-command of an aircraft for non-commercial purposes. This certification permits individuals to fly for personal enjoyment, travel, or recreation, but it prohibits any form of compensation or commercial operations. This means that a private pilot can fly passengers or property but cannot charge for their services.

The other options relate to different functions or privileges that are not covered under the private pilot certificate. Operating a commercial airline requires a commercial pilot certificate, which entails more advanced training and specific qualifications. Instructing other pilots requires a flight instructor certificate, which is a separate credential. Access to restricted airspace is subject to specific regulation and procedures, typically requiring communication with Air Traffic Control, and is not inherently granted simply by possessing a private pilot certificate.