What is the highest priority for interphone transmissions?

The highest priority for interphone transmissions is emergency messages. In aviation, the primary focus during emergency situations is the safety and well-being of all aircraft and personnel involved. Therefore, any message that pertains to an emergency, such as incidents requiring immediate attention or action, takes precedence over other types of communication. This ensures that critical information is communicated swiftly and clearly, allowing for a timely response to potential threats to safety.

While control instructions, flight plans, and movement messages are certainly important in the overall operation of air traffic control and flight management, they do not hold the same level of urgency as emergency messages. In situations where safety is at risk, the need for prompt communication regarding threats or emergencies is paramount, making it the highest priority in interphone transmissions.