Plain English Meaning

A remote radio relay box on the ground that lets you talk to Flight Service even when you're too far away to reach them directly. You call on the published frequency and your voice is carried back to the Flight Service Station for you.

Full Definition

An unstaffed ground-based radio facility that gives pilots a way to talk to a Flight Service Station (FSS) from areas where direct radio contact with the FSS would otherwise be out of range. The RCO transmits and receives on published frequencies and relays the communication to the controlling FSS over a dedicated link, allowing to or close , get , or up .