When does the airworthiness certificate remain valid?

The airworthiness certificate remains valid as long as maintenance is up-to-date and the aircraft is registered. This is because the airworthiness of an aircraft is contingent upon it being properly maintained according to the regulations set forth by the FAA. Regular maintenance ensures that the aircraft meets safety and operational standards. Additionally, the aircraft must be registered to maintain its airworthiness status, as this ties the aircraft to a specific owner and allows for ongoing oversight by aviation authorities.

It's important to note that merely flying the aircraft every month does not guarantee its airworthiness—maintenance records and compliance with inspection schedules are critical factors. Renewal of the airworthiness certificate is not an annual requirement, as airworthiness is maintained as long as the necessary upkeep is performed; thus, the option suggesting yearly renewal is misleading. Finally, keeping the aircraft in a hangar does not directly affect its airworthiness status; instead, the focus should be on maintenance and registration.