ATC Explained: What are Standard Terminal Arrival Routes?

As a flight begins its descent into the UK, it will transition from a ‘cruising phase’ as it approaches the vicinity of an airport. At this point, the aircraft will join a Standard Terminal Arrival Route, also known as a STAR. STARs are pathways that safely and predictably guide aircraft towards an airport’s terminal control area. The STAR is the last part of a journey before an aircraft is transferred to an approach controller to be guided into the runway for landing.

In simple terms, a STAR acts as a predictable track for arriving traffic to follow, helping everyone keep aircraft where they should be, when they should be there.

 

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How does a STAR work?

A STAR sets out a sequence of waypoints, level constraints and speeds that aircraft must adhere to. As a pilot enters a STAR, Depending on the airport an aircraft is landing at there will be multiple STARs; the direction an aircraft enters UK airspace from will guide which STAR is used for each flight.

On the other side of a journey, there are SIDs, or Standard Instrument Departure routes. Similar to STARs, SIDs have specific route guidance to help pilots and controllers guide aircraft up into the UK’s upper-level airspace.

Example of STARs: Included are the points an aircraft enters a STAR, the flight level (altitude), heading degrees to the next waypoint, and distances between waypoints (in nautical miles). At the end of the STARs are the holding positions.

Why do STARs matter?

These predetermined routes offer safety and predictability for controllers and pilots. STARs help aircraft flow in sequence and will reduce the need for last-minute manoeuvring, maximising operational efficiency. Having set routes means there is a reduced workload and radio output as pilots can follow a defined and predictable path, meaning less intervention is required from Air Traffic Controllers.

Continuous Descent Operations are enabled with well-structured routes, which means aircraft can avoid stepped descents and descend smoothly, bringing sustainability and noise benefits to those on the ground. A well-designed route also offers more direct paths, reducing route mileage which directly contributes to lower fuel burn and emission savings.

How are STARs designed?

Every STAR placement is a compromise between a variety of factors, including terrain, nearby airports, hold positioning, and traffic flow.

On top of the fixed, physical elements that must be considered, the design team also need to account for all other traffic flows in the region, including arrivals and departures into other airports, and safe and distanced sequencing of flights. In order to keep track of all these variables, we use advanced design tools and simulations to ensure the routes remain safe and efficient.

When STARs need to be updated or redesigned, they go through a structured airspace change process. This includes developing design options, assessing impacts, and consulting with stakeholders before anything is finalised.

Want to learn more about the exciting world of aviation? Check out the rest of our ATC Explained blog series or keep an eye on our socials for our video series!