What primary action must be taken once a southbound KVKS departure is approved?

The primary action that must be taken once a southbound KVKS departure is approved is to make a call to ZHU to coordinate. This step is crucial as it ensures that all relevant air traffic control units are informed and can manage the aircraft's integration into the larger airspace effectively. Coordination with ZHU, which likely refers to an air traffic control center, ensures that the departure complies with the appropriate air traffic management protocols, maintains safety and efficiency, and allows for the necessary traffic management and navigational support as the aircraft departs.

In air traffic operations, effective communication among various control centers is essential, especially for departures that may impact high-density airspace or involve specific operational routes. Therefore, notifying ZHU and ensuring proper coordination is a pivotal action in managing the flight's transition from departure to its subsequent routing.