When must a journey log be carried on an aircraft?

A journey log must be carried on an aircraft at all times to ensure compliance with regulatory requirements. This log serves as an essential record that includes details such as flight time, landing locations, and other important information specific to the operation of the aircraft. Having the journey log on board is crucial not only for commercial operations but also for private flights. The regulation stipulates that it must be retained in the aircraft unless there is a specific circumstance, such as when the aircraft will not land and shut down elsewhere, which would exempt it from this requirement.

The other options imply limitations where a journey log might not be necessary. However, the regulations governing the operation of aircraft mandate that the journey log is a continuous requirement for all types of flights and is integral for safety, accountability, and efficient management of flight operations.