¶ Overview
A STAR is an ATC coded IFR arrival route established for application to arriving IFR aircraft destined for certain airports. Its purpose is to simplify clearance delivery procedures and facilitate transition between en route and instrument approach procedures. STARs are similar to SIDs in that they both have initial fixes and transitions.
In the US we differentiate between two types of STARs:
- RNAV arrivals and non-RNAV arrivals.
In the video below you can learn the differences and how to apply them as ATC.
Video content is available as article below
https://www.youtube.com/watch?v=uEd5s8WfMDs
https://www.youtube.com/watch?v=2U_I3EBB5lk
Article credit: FlightInsight
¶ RNAV Arrivals
Example: CAPPS 3 RNAV Arrival for Washington National Airport (KDCA).
This STAR is designed to connect arriving aircraft directly to an initial approach fix for an instrument approach. The arrival ends at the KATRN and Intersection, which conveniently aligns with the first fix of the ILS approach to Runway 1. We can also see the note that only jet aircraft ar authorized for this procedure as turbo-prop aircraft would simply fly too slow.
¶ Understanding the Arrival Chart
The arrival chart provides important information, including speed and altitude restrictions, as well as distances between fixes. It’s important to note that the symbols on the chart, such as minimum enroute altitude (MEA) and minimum obstruction clearance altitude (MOCA), are not the altitudes pilots are supposed to fly on the arrival. They are just reference points to ensure safe navigation.
¶ Descend via
Once ATC issues the clearance:
CTR: “Descend via the CAPPS3 arrival, Washington National is landing north.”
Aircraft are required to follow the descend profile of the STAR. This includes altitude, speed, and routing. Highlighted in yellow are examples of different crossing restrictions.
Landing North:
- Cross CAPPS between 10000-13000ft MSL
- Cross HOYAS exactly at 9000ft MSL.
Landing South:
- Cross CAPPS between 10000-13000ft MSL
- Cross FLIPS at or below 11000ft MSL and at 280 knots (IAS)
- Cross MOEJO exactly at 10000ft MSL and 250 knots (IAS)
¶ ATC Restrictions
ATC can issue additional restrictions. For example:
CTR: “Descend via the CAPPS3 arrival, except cross CAPPS at and maintain 11000, Washington National is landing north.”
- This means aircraft are still required to descend via the arrival but cross CAPPS at 11000 and wait for further descend.
CTR: “Descend via the arrival, delete speed restrictions.”
- This means aircraft can descend without matching speed restrictions.
¶ Minimum Altitudes
In the example shown above highlighted in blue:
- 4000 is the MEA (minimum enroute altitude)
- *1600 is the MOCA (minimum obstruction clearance altitude).
¶ Following the Arrival Route
The CAPPS 3 Arrival flows aircraft onto the approach course, represented by the localizer and glideslope. As the aircraft descend, they must adhere to the altitude and speed restrictions specified on the chart. These restrictions help manage the flow of traffic and ensure safe separation between aircraft.
Profile view opf the arrival:
¶ STAR Transitions
ATC may cleare aircraft to fly the arrival and include which runway to expect, indicating which transition the aircraft should fly. CAPPS3 has 2 arrival transitions. One for landing north, and one for landing south.
¶ Landing North:
¶ Landing South:
¶ Planning the Descent
Before reaching the first fix of the arrival, pilots need to plan their descent carefully. A good rule of thumb is to calculate the distance based on the amount of altitude they need to lose. For example, if they need to descend from flight level 390 to flight level 210, they should start their descent approximately 54 miles away from the first fix.
¶ Waypoints
RNAV arrivals typically use following types of fixes:
- Flyby waypoint: Aircraft can start turning toward the next waypoint before reaching.
- Flyover waypoint: aircraft must cross, then turn toward next waypoint.
¶ Non-RNAV Arrivals
Non-rnav arrivals can be performed simply by VOR/DME navigation. A good example is the IRONS STAR at KDCA.
¶ Restrictions
Only lateral restrictions apply. Altitude and speed restrictions are not required. Pilots can plan to expect crossing a fix at a certain altitude but this is up to ATC.
CTR: “Cleared via the IRONS7 arrival, descend and maintain cross PEGBY at 13000, Washington National is landing north.”