Who is responsible for ensuring safety onboard an aircraft?

The correct answer, which identifies the responsibility for ensuring safety onboard an aircraft, is the Cabin Safety Inspector. This role is crucial as it focuses specifically on the safety protocols and compliance measures that are implemented within the cabin environment. The Cabin Safety Inspector conducts safety checks, ensures that safety equipment is available and functional, and verifies that cabin crews are adhering to safety procedures before and during flights.

In this context, while the Chief Pilot does hold significant responsibility for the overall safety of the aircraft, including the crew's operations and the flight's conduct, the Cabin Safety Inspector's role is more focused on the immediate cabin safety aspects. The Crew Scheduler primarily handles the scheduling of crew members and does not directly oversee safety. Ground Control is involved in managing the aircraft on the ground and ensuring safe operations in that environment, but they do not oversee the safety of the aircraft while it is in the air. Hence, the Cabin Safety Inspector is specifically tasked with ensuring that safety measures are effectively implemented and maintained onboard during flights.