When should aircraft switch to NMOA Common on CH15 after being cleared a block in the NMOA?

Switching to NMOA Common on CH15 should occur once the aircraft is within the lateral confines and working altitudes of the assigned block. This ensures that aircraft are communicating effectively with other aircraft in the area and allowing for proper coordination. By waiting until within the designated airspace, pilots can confirm they are in the correct position and altitude, which enhances safety and situational awareness.

It allows for real-time updates and coordination with other aircraft that might also be operating in the same area, preventing potential conflicts and improving the overall efficiency of operations within the NMOA. This practice aligns with standard procedures to ensure that communication is relevant and effective, avoiding unnecessary chatter before entering the block.