I need to check if any of the VFIRE interop freqs are used by aircraft.
I haven't heard the aircraft use VFIRE channels very often. Most of the air-to-ground traffic I have heard is between the air attack plane and the TFS fire supervisors on the TFS air-to-ground channels.
Sometimes if there are several fires near eachother the IC (or whoever in in charge of the incident communications plan) might move air-to-ground to a VFIRE channel or a federal channel (according to the TSCIP VFIRE26 is supposed to be only for air-to-ground with state/federal aircraft).
A couple times I heard the air attack plane try to contact local ground units on a VFIRE channel when there weren't any TFS units at a fire yet. The VFIRE channels are mostly used as tactical channels by the locals.