Not for chatting with pilots.

In practical

That said, in practical the FCC is not able to enforce the corresponding regulation and transceivers are freely available.

Still if an unlawful transmission disrupts or interferes with legitimate services or causes an incident, FCC and/or FAA may investigate and take the author to a court.

Bands available to the general public for private/business use

Services/frequencies open to the general public, without constraints on the content of the message include:

• Citizen Band Radio Service (CB), HF, no license required.
• Family Radio Service (FRS), UHF, no license required
• Multi Use Radio Service (MURS), VHF, no license required
• General Mobile Radio Service (GMRS), UHF, license required

There are other services, like the radioamateur service, open to the general public, but the license is granted after passing an exam and the content of the messages is (at least on the paper) constrained to technical topics related to radio experiments.