What should you check in the Journey log to ensure the aircraft is airworthy?

To determine whether an aircraft is airworthy, one must check the last entry of current air time recorded in the Journey log. This log provides essential information about the aircraft's usage and maintenance status. The current air time is significant because it helps to evaluate whether the aircraft has been operated within the parameters set by the manufacturer and regulatory authorities. It may impact maintenance schedules, ensuring that the aircraft has not exceeded allowable flight times between required inspections or servicing.

The other options, while they may provide some information about the aircraft's history or ownership, do not directly contribute to assessing airworthiness. For instance, the last route flown does not give insight into the maintenance or condition of the aircraft. The owner's address is not relevant to its airworthiness, and while the inspection sticker date can be important, it is not the most immediate indicator available in the Journey log related to ongoing airworthiness. In this context, checking the last entry of current air time is the most crucial factor in affirming that the aircraft is fit for flight.