Under what conditions is a person not allowed to act as a flight crew member?

A person is not allowed to act as a flight crew member if they are under a physical disability because the regulations require all flight crew to have the ability to physically perform the duties of their role. This includes being able to handle the aircraft controls, communicate effectively, and respond to emergency situations without physical limitations. The physical fitness of pilots ensures safety for both the crew and passengers, as it affects their ability to operate the aircraft reliably.

While logged flight hours are necessary for demonstrating experience, they do not disqualify someone from flying if they are otherwise physically fit. Completing a medical review is crucial, but if a person has not completed this step yet, the focus is on the lack of current medical clearance rather than a physical disability. A new pilot can operate as a flight crew member as long as they meet all training and medical requirements, so being new is not a disqualifier.