When leaving TRSA what is the correct phraseology to tell ATC that radar service is no longer desired?
You can say "cancel radar service" (probably the most standard under ICAO), "cancel flight following," "request frequency change," or anything else that conveys the same general idea. If all else fails, plain English is always acceptable too.
Regardless of which you say, ATC's response should be "radar service terminated, squawk VFR, frequency change approved," same as in any other class E airspace.
On takeoff, tower will typically tell you to contact approach as you start your climb. After you do that, and if VFR and not on flight following, you just report "Binghamton approach, Nxxxxx is clear to the east" as an example, and can add your altitude. Binghamton, NY TRSA is the nearest one I fly thru with any sort of regularity (couple times a year). Basically you can treat them like a Class C as the TRSA is likely to be centered around a towered airport, while Class D may or may not be.
If you ask for flight following prior to takeoff, Gnd control, or the tower, can set you up with a squawk code so that approach has you in the system already when you contact them.
I always use flight following when flying cross country, nice to have another set of eyes looking out for you, and it expedites handoff to Center, or the next approach control, depending on where you are. We're also under a Class B shelf, so it can be busy.
There are still planes without ADS-B, some illegally, some not needing it due to staying out of radio required airspace, or due to not having electrical systems, so all due diligence helps.
There is recommended verbiage per AIM 4-1-18-b.2:
- If any aircraft does not want the service, the pilot should state “negative TRSA service” or make a similar comment, on initial contact with approach control or ground control, as appropriate.
In the United States, participation in radar services such as flight following by VFR traffic is not mandatory. It is recommended for pilots flying VFR as a non-regulatory service. Two-way communication for VFR traffic before entering and while within Class B, C & D airspace, and within 4 miles of a towered airport below 2500 feet AGL, is still required. Outside of these areas, communication with ATC by non-participating VFR traffic is optional only. This also applies to airspace within the TRSA (communication with the underlying Class D is still required). Communication rules for IFR still apply to IFR traffic regardless.
If you are already participating in radar services like flight following as VFR, you can ”cancel” ”terminate” or ”discontinue” the service in plain English. There is no mandatory phraseology for the pilot. No reason has to be given.