What is the separation minima for longitudinal and crossing aircraft operating within an ALTRV in oceanic airspace?

In oceanic airspace, when aircraft operate within an ATC designated ALTRV (Altitude Reservation), the separation minima between longitudinally and crossing aircraft is set at 60 minutes. This extended separation time is crucial due to the unique challenges posed by the vast distances and limited radar coverage over the ocean, which necessitate larger separations to prevent potential in-flight conflicts.

The 60-minute separation ensures that even in the event of minor deviations or changes in speed by one of the aircraft, there is enough buffer time to maintain safety and reduce the risk of mid-air collisions. This protocol emphasizes the importance of maintaining a safe operational environment in areas where communication and tracking capabilities are more limited than they would be in more congested airspaces. In contrast, the other options reflect shorter separation times that do not adequately account for the dynamics involved in oceanic flight operations.