Under what condition may an aircraft due for an annual inspection be flown?

An aircraft that is due for an annual inspection may only be flown under specific conditions outlined by aviation regulations, and one of those conditions is if a special permit has been issued. This special permit, often referred to as a "ferry permit" or "special flight permit," is granted under certain circumstances when the aircraft is not in compliance with airworthiness requirements, but still needs to be moved to a location where necessary maintenance or inspections can be performed.

Earning such a permit typically involves demonstrating that the flight can be conducted safely and that the need for the flight outweighs the risks associated with operating the aircraft in an uninspected condition. This allows for the safe operation of the aircraft despite it not meeting its annual inspection requirements, ensuring that necessary precautions are taken for safety during the flight.

The other options, such as certification by a mechanic or inspection by the owner, do not meet the regulatory requirements for flying an aircraft that is due for an annual inspection as they do not provide an official exemption or allowance to operate an aircraft that is not fully airworthy according to the defined maintenance schedules. Thus, a special permit stands as the only viable condition in which such an aircraft may be flown legally.