SID and STAR: understanding departure and arrival routes and finding them on charts

An Airbus lifts off, climbs straight ahead – and after a few kilometers suddenly turns sharply south, away from your spot. The next day the same connection passes directly over you. That is no coincidence: behind every turn are SID and STAR, an airport’s defined departure and arrival routes. This guide explains what is behind the abbreviations, how to decode the cryptic names, where to find the official charts and how to use the knowledge to choose spots around the airport deliberately.

SID and STAR: the short answer

A SID (Standard Instrument Departure) is a standardized departure route for flights under instrument flight rules. It begins at the end of the runway and leads over defined points to a waypoint in the route network, from which the flight follows its planned route. A STAR (Standard Terminal Arrival Route) – called Standard Instrument Arrival by ICAO – is the counterpart: it picks the flight up from the route network and brings it to the point where the actual landing approach begins.

Both procedures serve the same purpose: they organize traffic in the dense airspace around an airport. Instead of dictating a route to each aircraft individually, the controller just says the name of the procedure – and pilot, onboard computer and air traffic control know which turns, altitudes and often speeds are meant.

Why fixed routes exist at all

Around a large airport, departing and landing aircraft cross, and on top of that there are neighboring airports, military areas and airspaces with different rules. Standard routes solve several problems at once:

• Obstacle clearance: Every route is designed so that aircraft with prescribed minimum altitudes and climb rates safely clear terrain, masts and buildings.
• Separation of flows: Departures and arrivals are guided so that they interfere with each other as little as possible. That reduces radio workload and relieves controllers.
• Noise protection: Departure routes are meant to avoid densely populated areas where possible. In Germany, the aircraft noise commissions are involved in the planning, and some routes only apply at certain times of day.
• Predictability: Because the procedures are stored in the aircraft’s navigation databases, the crew can load them into the flight management system in advance.

In Germany, the DFS German Air Navigation Services designs the procedures, and they are established by the Federal Supervisory Authority for Air Navigation Services (BAF) by statutory ordinance, an implementing ordinance to the Air Traffic Regulations (Luftverkehrs-Ordnung). That also explains why new or changed departure routes are often publicly debated for months.

How to decode the names

At first glance the designations look like a secret code. In Europe, though, they almost always follow the same three-part pattern. Take the fictional example KOBAL 2N:

Component	Example	Meaning
Waypoint name	KOBAL	For a SID the point where the route ends; for a STAR the point where it begins
Digit	2	Version number; it goes up when the procedure is changed
Letter	N	Distinguishes runways or variants that lead to the same waypoint

On the radio you hear it spoken out, so “KOBAL Two November”. The waypoint names themselves are usually five letters long and are meant to be easy to pronounce and unique worldwide. There are also procedures named after radio beacons; their identifier is shorter.

For you as a spotter, the name holds valuable information: the waypoint reveals the rough compass direction in which a flight leaves the airport or from which it comes. Flights in the same direction often use the same exit points, no matter which city they ultimately fly to. The letter usually depends on the runway – when the runway direction in use changes, the letters change too, and with them the turns the aircraft fly.

Structure of a SID

A SID begins at the departure end of the runway. Typical components on the chart:

• Initial climb: Usually it first goes straight ahead to a certain altitude or distance before the first turn. This section determines where you still see departing aircraft low and on the runway centerline.
• Turns and waypoints: After that the route follows a chain of waypoints or radio beacons. At individual points there are altitude constraints such as “at or above” or “at or below”, and in some cases speed limits in turns.
• Initial altitude: The chart gives an altitude up to which the aircraft may climb without further clearance. Going higher only happens on the controller’s instruction.
• End point: At the last waypoint the SID merges into the route network.

One detail is especially important for spotters: in practice many departures are not flown to the last point on the chart. As soon as traffic allows, the controller gives a clearance direct to a later waypoint. The first turn and the initial climb usually stay as published, though – exactly the part that counts for choosing a spot.

Structure of a STAR

A STAR begins at a waypoint in the route network, often far from the airport. From there it leads the flight in descent over further points to the vicinity of the airport. Its end lies where the actual approach procedure begins, typically at an initial approach fix. From there the approach procedure takes over, often an ILS approach, or the controller guides the aircraft onto final with heading instructions.

Along the STAR on the chart you find:

• Altitude and speed constraints with which the descent is staggered.
• Holding procedures at certain points. When things get busy, aircraft circle there in holding until they may continue. What that looks like is explained in the guide Holding patterns; on the flight tracker you recognize them by the typical ovals, see Recognizing holding patterns on the flight tracker.
• Transitions to the approach: At some airports, additional procedures are published that lead the aircraft from the end of the STAR to final.

European STARs are often very detailed. Nevertheless, in everyday operations: with moderate and heavy traffic, many approaches are guided by radar vectors to set the spacing on final exactly. The line on the chart then shows the corridor rather than the actual track.

Where to find the charts

The binding SID and STAR charts are in the Aeronautical Information Publication, the AIP. Every country publishes its own AIP, but the structure is largely standardized by ICAO: there is a general part (GEN), an en-route part (ENR) and an aerodrome part (AD). You find the departure and arrival charts in the AD part under the respective airport, together with the aerodrome chart, which you learn to decode with the guide Reading AIP aerodrome charts.

For Germany, the DFS provides the AIP IFR online. For Austria and Switzerland, the respective air navigation service providers are responsible, more on that in the article on Austro Control and Skyguide. Changes to procedures follow the AIRAC cycle: every 28 days new editions take effect so that airlines and manufacturers of navigation databases can load the data in time.

Source	What you find there	Suitable for
The country’s AIP (e.g. DFS)	official SID, STAR and approach charts with all altitudes and constraints	anyone who wants to know exactly
Airport flight track and noise portals	tracks actually flown over residential areas	Spotters looking for real corridors
Flight tracker services	live tracks of individual flights, often with altitude	Planning on spotting day
Flight sim chart services	processed charts, mostly by subscription	Flight sim fans who pay anyway

Important: the AIP charts are meant for aviation. For spotting, looking at them is enough – after all, you don’t have to fly them. If the topic keeps appealing to you, take a look at flight simulation, where you can fly SIDs and STARs yourself.

Chart meets reality: comparing flight tracks

The most exciting exercise for spotters is comparing paper and practice. Open an airport’s SID chart and next to it a flight tracker with the tracks of the latest departures. You will see:

• The initial part almost always matches. Straight flight, first turn and climb follow the procedure because obstacles and noise protection leave no room for maneuver here.
• Later the tracks fan out. Direct clearances shorten the route, the lines diverge.
• On approach, tracks only bunch together shortly before final. Before that, wide fans form because controllers set the spacing with heading instructions.

The flight track portals of many airports, which are actually meant for noise information, are especially revealing. How to use them as a spotter tool is covered in the guide WebTrak and aircraft noise portals. Anyone following tracks live should know the symbols and colors on flight tracker maps – then you read altitude and climb or descent rate directly. The basics of position data are explained in Flight tracking with ADS-B for spotters.

What SID and STAR mean for your choice of spot

Now it gets practical. With the combination of chart, runway designation and runway direction in use, you can search for locations deliberately.

An example of the effect of runways and routes is Frankfurt Airport: Runway 18 West is only used for takeoffs toward the south, so departures from there inevitably head in a different direction than those from the parallel runways. Anyone standing at the Zeppelinheim viewing platform experiences very different pictures depending on the runway direction in use. At Munich Airport with its two parallel east-west runways, the runway direction in use decides whether takeoffs or landings are in the foreground at the visitors’ hill. Further locations are presented in the guides Plane spotting in Frankfurt and Plane spotting in Munich; how to estimate the runway direction in use in advance is shown in the article on Windy and weather maps.

SID and STAR on aviation radio

Anyone who listens to aviation radio encounters the procedures constantly. Before departure the crew receives its route clearance, which contains, besides the destination airport and transponder code, the SID to be flown. On arrival the controller assigns or confirms the STAR, followed later by descent clearances, heading instructions and finally the approach clearance. If you hear a certain waypoint name along the way, with a bit of practice you immediately know from which direction a flight is coming in. Which frequencies are responsible for what is explained in the guide Understanding aviation radio frequencies; what is legally allowed is covered in Listening to aviation radio: legal situation.

What to watch out for

• Always use the current edition. Procedures change on the AIRAC cycle. Old screenshots or charts from forums can be outdated.
• Chart is not the same as track. The published line shows the procedure, not every individual track. Plan with corridors, not with meters.
• Mind the altitudes. Far from the airport, aircraft even on a STAR are often so high that photos are hardly worthwhile. It usually only gets interesting near the airport.
• Know the night rules. At some airports different routes or restrictions apply at night; more on that in the article on the night flight ban.
• Check accessibility. A route over a field does not make the field enterable. Stay on public paths.

Conclusion

SID and STAR are the fixed paths on which instrument flights leave and reach an airport. In Europe their names follow a clear logic of waypoint, version and identifying letter, and the charts are freely viewable in the AIP. For spotters the real value lies in cross-checking: chart, runway direction in use and live tracks together show where aircraft really turn away and swing in. Once you have worked through this for your home airport, you will find spots that are on no list.