What is the primary requirement to carry a Journey Log on board?

The primary requirement to carry a Journey Log on board is that it must be present anytime the engine will be shut down other than at the departure airport. This regulation helps ensure that all pertinent details regarding the flight are documented in a consistent manner. The Journey Log serves as a record of the flight, including flight times, routes, destinations, and any other operational notes that may be required for safety and regulatory compliance.

Having the Journey Log accessible during a flight provides important information for the pilot and any necessary regulatory authorities. It promotes accountability and contributes to safe flight planning and execution, particularly in scenarios that involve various legs of a journey or multiple destinations.

The other options do not pertain directly to the requirement for the Journey Log. For instance, the stipulation regarding IFR flight capabilities or the distance from the departure aerodrome does not override the need for a Journey Log when the aircraft transitions to a different location. The condition concerning engine shutdown at an airport or other specifics does not alter the core requirement focused on situational logging and accountability.