I'm not sure I would use incommunicado to describe an RC plane that was unable to receive signals except in a tongue-in-cheek sort of way. The plane never had the ability to transmit information back to you in the first place, so technically it cannot be deprived of the ability to "communicate." If Maoist rebels captured you and deprived you of your control device, it could be said that the plane crashed because you were incommunicado.