Under what condition can a private pilot carry a passenger who is under the influence of drugs?

A private pilot may carry a passenger who is under the influence of drugs in an emergency situation. This is because the primary concern in an emergency is the safety and well-being of all individuals on board, including the passenger. In such cases, the pilot's judgment may prioritize resolving the emergency over the typical regulations regarding drug use by passengers.

It is essential to understand that general aviation regulations place significant emphasis on the responsibilities of pilots to ensure that all passengers meet certain standards, particularly those related to health and safety. In ordinary circumstances, carrying a passenger under the influence could complicate emergencies or impair the passenger's ability to follow instructions, potentially increasing risk. Thus, it's the gravity of an emergency scenario that sets this condition apart, allowing for greater flexibility in decision-making.