If you are cleared to "descend via" a published standard terminal arrival (STAR), what must you do?

When cleared to "descend via" a published standard terminal arrival (STAR), it is essential to adhere to the published altitude crossing restrictions and speed control unless otherwise specified by ATC. This instruction means that the pilot must follow the specified altitudes and speeds indicated in the STAR as they descend, ensuring safety and synchronization with other aircraft operating in the same terminal airspace.

The key aspect of a STAR is its structure, which is designed to provide a safe and efficient transition from the en route phase to the approach phase of flight. By following these published procedures, pilots help maintain orderly and predictable traffic patterns, which is crucial in busy airspaces.

Moreover, the phrase "descend via" indicates that the controller is giving the pilot authority to follow the STAR as published. This requires compliance with the detailed instructions provided, which include specific altitude transitions and speed restrictions designed to optimize the flow of air traffic into the terminal area. Therefore, it's critical for pilots to pay attention to these published guidelines to ensure safety and regulatory compliance throughout the descent.