Is there a map I can refer to in order to pick up the correct frequency for VFR flight following while enroute? I know I can request a frequency from ATC as I depart, but what if I want to fly around and do sight seeing, practice maneuver for my checkride etc. for a while, then pick up flight following for the remainder of the trip?
There are three types of ATC service: terminal, approach control, and center (ARTCC).
Since you said you're en route, you'll want either approach control or center.
If you're inside the Mode C veil (but obviously not already in the airspace) of a Class B or Class C, or if you're near a military base (which all have radar, 'natch), you'll watch to contact approach control, whose frequencies can be found on the tabs of the sectional, such as this example from San Francisco:
If you're not within the Mode C veil, call up Flightwatch 122.0.
Flightwatch is manned at all times, but it usually takes them at least 5-10 seconds to respond because its infrequently used and they're busy with other things. The trick is not to make your request on the first call up, but do announce your position, since Flight Service has many transmitters, and they will pick the one that is closest to you:
N347T: Flightwatch, Mooney 3-4-7-Tango, Crazy Woman
10 seconds pass...
Fligihtwatch: Mooney near Crazy Woman, Flightwatch, go ahead (they probably won't get your numbers, but they will pick out your type and position)
N347T: Flightwatch, Mooney 3-4-7-Tango, what's the frequency for flight following near C-Z-I?
Flightwatch: 4-7-Tango, for radar services near C-Z-I, contact Salt Lake Center on ....
Many GPS units have a "nearest" function that will provide frequencies for the nearest FSS or Center:
I assume you're in the US? If you got flight following when you departed from a controlled field then ATC should tell you if you need to change frequency, unless of course they have to stop providing you the service because of workload or whatever.
In general, flight following is provided by the nearest TRACON or ARTCC, so you can look in at least three places, two of which are maps:
- The VFR chart, if you're near a controlled field, which shows the TRACON frequencies
- The IFR en route chart, which shows the ARTCC frequency for your general area even if you're not close to a controlled field
- The Chart Supplement, if you're near a controlled field
My own experience with flight following, from operating out of both towered and non-towered fields in the Carolinas: After taking off on an XC from my non-towered home field, depending on my heading, I contact the nearest approach control, for example, Wilmington NC (KILM) or Myrtle Beach (KMYR). Before taking off from a towered airport, I will ask the ground controller for FF and get a squawk code and post-departure contact frequency. (ATIS at some of airports I have flown into include instructions for requesting FF); to back that up, if I have not already requested FF, ground or tower controller may be proactive and offer it to me. Airspace around busy airports can be crowded, and I feel safer knowing that I am not an unidentified blip; ATC knows where I am, and what I am doing, and can redirect me if necessary. Positive communication is key to staying safe.