Which of the following is NOT a purpose of STARs (Standard Terminal Arrival Routes) and SIDs (Standard Instrument Departures)?

• A. They enhance terrain and obstacle avoidance during arrival and departure.
• B. They reduce air traffic congestion by providing predefined routes.
• C. They standardize communication between pilots and controllers.
• D. They eliminate the need for air traffic control clearance.

Answer: (D)

STARs and SIDs are published routes that guide aircraft from general airspace into and out of a specific airport’s terminal area. They’re designed to keep traffic flowing smoothly, safely, and efficiently by providing predefined paths that help separate arriving and departing aircraft.

They enhance terrain and obstacle avoidance because the routes specify altitudes, step-downs, and turn directions that keep aircraft clear of terrain and fixed obstacles as they transition through busy segments of airspace. They also help reduce air traffic congestion by giving everyone a common, predictable path, which makes sequencing and spacing easier for controllers and pilots. Standardizing the route and the expected flow also encourages consistent phraseology and procedures, which lowers the chance of miscommunication between pilots and controllers.

What they do not do is eliminate the need for air traffic control clearance. A SID is a clearance-driven departure, and a STAR is an arrival path that a controller assigns you as part of your clearance. You still need ATC authorization to fly those routes and to receive any necessary altitude, speed, or route instructions along the way.