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Approach — Introduction to Radar Last updated: 2018-01-23

Congratulations on passing your tower training, welcome to the TRACON!


TRACON stands for Terminal Radar Approach CONtrol. Your job is to get departures from the terminal area to the en-route phase of flight and to bring arrivals from the en-route structure to the terminal environment.


At the tower level, you used mostly visual techniques to separate aircraft (although some do have certified tower radar displays (CTRDs)). At the TRACON you will only use radar. Radar stands for RAdio Detection And Ranging. It works by sending out radio signals, detecting reflected waves, and displaying a target on the radar scope. This target is known as a primary target and doesn’t indicate any other information. However, most aircraft are equipped with transponders that transmit other information such as altitude, speed, and beacon code. This is known as a secondary target.


For approach control, the typical radar site is called Airport Surveillance Radar (ASR) and is normally located at the airports. The most modern kind of radar is ASR-11, which consists of a primary surveillance radar and a secondary surveillance radar. The primary surveillance radar uses a continually rotating antenna mounted on a tower to transmit electromagnetic waves that reflect, or backscatter, from the surface of aircraft up to 60 miles from the radar. The radar system measures the time required for a radar echo to return and the direction of the signal. Using this information, the system can then measure the distance of the aircraft from the radar antenna, as well as the azimuth (direction) of the aircraft in relation to the antenna. The secondary radar uses a second radar antenna attached to the top of the primary radar antenna to transmit and receive area aircraft data for barometric altitude, identification code, and emergency conditions. Military, commercial, and some general aviation aircraft have transponders that automatically respond to a signal from the secondary radar by reporting an identification code and altitude.


Approach Training


Your approach training will start at the San Diego Area of the Southern California TRACON (SCT). Within your area of jurisdiction, you will provide approach services into San Diego International Airport and its satellites.

ZLA supports both VRC and vSTARS as approach clients, but the former is recommended for new students. vSTARS adds another layer of realism but is much more complex. Once you are comfortable with basic approach techniques, you may choose to learn how to use vSTARS.

VRC supports ARTS and STARS radar modes. The FAA is currently changing most TRACONs from ARTS to STARS and the real L30 uses STARS. However, VRC doesn’t completely model the real STARS radar mode so we encourage you to use ARTS with VRC for approach positions.