Who is responsible for ensuring the airworthiness of an aircraft?

The registered owner of the aircraft holds primary responsibility for ensuring its airworthiness. This responsibility is deeply rooted in aviation law and regulations, particularly those set forth by the Federal Aviation Administration (FAA). The owner must maintain the aircraft in a condition that adheres to safety standards established by the FAA, which includes conducting regular inspections, maintenance, and any necessary repairs to keep the aircraft safe for flight.

While the pilot in command also plays a crucial role in determining the airworthiness before each flight, it is the registered owner who is ultimately accountable for the overall condition and compliance of the aircraft. The manufacturer of the aircraft does design and build the aircraft to certain specifications, but it is the owner's duty to maintain and operate it in accordance with regulatory requirements. The FAA provides oversight and regulations but does not take on the responsibility of airworthiness for each individual aircraft.

Therefore, the correct answer reflects the owner's legal obligation to ensure that the aircraft is safe and compliant with aviation standards, fostering a culture of accountability within the aviation industry.