Terminal Radar Service Area


  • The Terminal Radar Service Area (TRSA) was originally established as part of the Terminal Radar Program at selected airports
  • TRSAs are delimited airspace in which radar and ATC services are made available for pilots under IFR or optionally for VFR traffic
  • Terminal Radar Service Areas were never was subject to the rule-making process and consequently, are not contained in 14 CFR Part 71 nor part Part 91 and not considered part of the airspace classification system
  • Part of the Airport Radar Service Area (ARSA) program was to replace the TRSAs
    • The ARSA requirements became relatively stringent and it was subsequently decided that TRSAs would have to meet ARSA criteria before they would be converted
    • Seeing as they do not fit into any airspace classes they will continue to be a non-part 71 airspace area where participating pilots can receive additional radar services which have been redefined as a TRSA service
  • In place to maintain aircraft separation
  • Often times TRSAs are being replaced with Class Bravo or Class C airspace
Terminal Radar Service Area
Terminal Radar Service Area (TSRA)

Terminal Radar Service Areas:

  • The primary airport(s) within the TRSA become(s) Class D airspace
  • The remaining portion of the TRSA overlies other controlled airspace, which is normally Class Echo airspace beginning at 700 or 1,200' and established to transition to/from the en-route/terminal environment as dark gray circles that look like Class Bravo airspace [Figure 1]


  • Pilots operating under VFR are encouraged (but not required) to contact the radar approach control and avail themselves of the TRSA services
  • See Chapter 4, Air Traffic Control, for details and procedures

Airspace Depiction:

  • TRSAs are depicted on VFR sectional and terminal area charts, however, it can be found listed in Chart Supplement U.S.
  • The TRSA itself is depicted with a solid black line and altitudes for each segment
  • The Class D portion is charted with a blue segmented line
  • Depicted on sectionals and TACs only

Radar Sequencing and Separation Service:

  • Implemented at certain terminal locations
  • Service is advertised in the Chart Supplement U.S.
  • Provides separation between all participating VFR and all IFR aircraft operating within the airspace defined as Terminal Radar Service Area (TRSA)
  • Pilot participation is urged but not mandatory
  • If an aircraft does not want this service then state "Negative TRSA Service" on initial contact or as appropriate
  • VFR aircraft will be separated from VFR/IFR aircraft by one of the following:
    • 500' vertical separation
    • Visual separation
    • Target resolution (a process to ensure that correlated radar targets do not touch) when using broadband radar systems
  • Participating aircraft must maintain an altitude when assigned, ATC may assign altitudes that do not conform with 91.159 (VFR cruising altitude or flight level)
    • When altitude restriction no longer applies ATC will advise "Resume Appropriate VFR Altitudes"
    • Pilots must then return to appropriate 91.159 altitudes as soon as practicable
  • When not assigned an altitude, the pilot should coordinate with ATC prior to any altitude change
  • Within the TRSA traffic information is observed but unidentified targets will, to the extend possible, be provided
  • Departing aircraft should inform ATC of their intended destination and/or route of flight and proposed cruising altitude
  • ATC will normally advise participating VFR aircraft when leaving the airspace, this does not mean the service has been terminated unless stated so
  • Class C Service: provides, in addition, approved separation between aircraft and sequencing for VFR arrivals to the primary airport
  • Class B Service: provides, in addition, approved separation between aircraft based on IFR, VFR, and/or weight, and sequencing of VFR arrivals to the primary airport(s)


  • Participation is voluntary on the part of the pilot