RE: What is the largest aircraft to have been flown first person ?
I don't know if a flying wing fits this category, but the NASA images website has the 1/4 scale Centurion model, which later became Helios (the solar powered plane that set an altitude record of ~97K ft). The model has a 62 ft wingspan and weighed 25 lb RTF. They used a 8 channel Futaba radio.