The copilot assists the pilot during flight, including handling the radio communications, navigation, and working with the pilot to complete the many checklists involved with flying an aircraft. The pilot may turn control over to the copilot even if the pilot doesn't leave the cockpit.

Why do Copilots exist?

The workload is shared between the two pilots, and each one's duties are well defined. While the captain is more senior and is ultimately responsible for the safety of the flight, both pilots are trained to handle all emergency situations equally professionally.

What is the purpose of ghost flights?

The airline has been operating such flights to keep its fleet operationally ready during COVID-related quiet periods. Ghost flights are nothing new. Many airlines have operated such flights to protect precious slots during quieter months or to move an aircraft between A and B.