B.B.C. reports: No flight plane filed. They do not know where to look. I expect that they will calculate max possible range for the aircraft and go from there.

I rather fear that unless he has put the plane down somewhere or has parachuted he is very likely dead. I hope not, but this might be a case of familiarity breeding contempt with fatal results. Also: Given his age it's quite possible that he has had a heart attack or something at the controls.

Hopefully he will show up tomorrow alive and with a good story.