What is the primary purpose of aircraft position reports?

The primary purpose of aircraft position reports is indeed to ensure traffic is separated by time intervals. Position reports provide critical information about an aircraft's location, altitude, and intended route, which is essential for air traffic controllers to maintain safe separation between aircraft in the airspace. By utilizing these reports, controllers can track the movements of all aircraft in their vicinity and make adjustments as necessary to prevent collisions and ensure efficient traffic flow. This is a vital aspect of air traffic management, as maintaining safe distances and time intervals between aircraft is crucial for safety in the skies.

The other options do not align with the fundamental role of position reports in air traffic control. Notifying of maintenance issues, while important, falls outside the scope of position reports, as they focus on the operational status rather than maintenance concerns. Providing weather updates is typically the responsibility of meteorological services and does not relate to an individual aircraft's position or separation strategy. Logging flight miles is more a matter of flight planning and accounting than a function of position reporting, which is focused on real-time air traffic management.