Final answer:
The party primarily responsible for maintaining an aircraft in an airworthy condition is the operator or owner of the aircraft. Aircraft maintenance technicians also play a crucial role in performing inspections and repairs.
Step-by-step explanation:
The party primarily responsible for maintaining an aircraft in an airworthy condition, including compliance with airworthiness directives, is the operator or owner of the aircraft.
Operators must adhere to maintenance schedules and procedures outlined by the aircraft manufacturer and regulatory authorities such as the Federal Aviation Administration (FAA) in the United States.
Additionally, aircraft maintenance technicians, also known as mechanics, play a crucial role in performing inspections, repairs, and routine maintenance to keep the aircraft airworthy.