Terminal Radar Service Area (TRSA) Description: - Surrounds Class D airports with expanded ATC radar services Requirements/Limitations: - Pilots are not required to participate - Transponder and two-way communication for participating aircraft - Rules for Class D airspace within apply regardless of pilot participation with TRSA radar services Question: Where do TRSAs fit in the national airspace classification system? Answer: TRSAs are " leftovers " from the previous (pre-1993) airspace classification system. As a general rule, they exist at airports where traffic load requires enhanced radar service, but that aren't busy enough to justify Class C airspace. Ref: AIM 3-5-6 © Air Safety Institute airsafetyinstitute.orghttp://www.airsafetyinstitute.org http://www.airsafetyinstitute.org