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I know this is a stupid question but...what is a TRSA(yes I know it is a black circle on the sectional
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Not stupid. A Terminal Radar Service Area. Similiar to the former Airport Radar Service Area (now Class C airspace), but participation is voluntary vs being mandatory....................
From AIM 3-5-6:
3-5-6. Terminal Radar Service Area (TRSA)
a. Background. TRSA's were originally established as part of the Terminal Radar Program at selected airports. TRSA's were never controlled airspace from a regulatory standpoint because the establishment of TRSA's was never subject to the rulemaking process; consequently, TRSA's are not contained in 14 CFR Part 71 nor are there any TRSA operating rules in 14 CFR Part 91. Part of the Airport Radar Service Area (ARSA) program was to eventually replace all TRSA's. However, the ARSA requirements became relatively stringent and it was subsequently decided that TRSA's would have to meet ARSA criteria before they would be converted. TRSA's do not fit into any of the U.S. airspace classes; therefore, they will continue to be non-Part 71 airspace areas where participating pilots can receive additional radar services which have been redefined as TRSA Service.
b. TRSA's. 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 E airspace beginning at 700 or 1,200 feet and established to transition to/from the en route/terminal environment.
c. Participation. Pilots operating under VFR are encouraged to contact the radar approach control and avail themselves of the TRSA Services. However, participation is voluntary on the part of the pilot. See Chapter 4, Air Traffic Control, for details and procedures.
d. Charts. TRSA's are depicted on VFR sectional and terminal area charts with a solid black line and altitudes for each segment. The Class D portion is charted with a blue segmented line.
You'd be surprised how many pilots don't know what a TRSA is. These are mainly newer ones who don't remember the airspace classifications prior to the current ones (pre-1991). Also, I can safely say most military guys probably don't know what they are unless they operate near ones in their area. You don't see TRSAs much anymore, and the only airport with a TRSA I can currently think of is Palm Springs, CA.
I remember when KPHX used to be a TRSA. It was when I was getting my Private at Sky Harbor. Changed to an ARSA during that time too.
Most definatley not a stupid question, i remember being a newly rated instrument pilot getting to fly at home for the first time, so when i was getting ready for my check out at the FBO i bought a sectional and my first thought was what the hell kind of airspace is this? It was in Monroe, LA, thankfully it was easy to learn and easy to use. The contollers there are really awesome.