I don't think he has to call it AF1. That is just the reserved call sign and can only be used when POTUS is on board of ANY aircraft to give priority spacing requirements. I flew out of an Airforce base years ago at the AERO Club as a civilian instructor (CFII), which was basically flight training available for anyone in the service. They had to pay it, but we flew C-172 (Cessna small plane) military designation as T-41. We could, if we wanted, request a call sign. One of the guys (a retired Colonel) that ran the club, requested Airforce Number 1. It was granted, and the controllers at the base knew, but when we flew a trip from Texas to Mississippi with that call sign and we had priority tasking the whole trip, cruising along at 9,000 ft and 120 knots. Good times.
I don't think he has to call it AF1. That is just the reserved call sign and can only be used when POTUS is on board of ANY aircraft to give priority spacing requirements. I flew out of an Airforce base years ago at the AERO Club as a civilian instructor (CFII), which was basically flight training available for anyone in the service. They had to pay it, but we flew C-172 (Cessna small plane) military designation as T-41. We could, if we wanted, request a call sign. One of the guys (a retired Colonel) that ran the club, requested Airforce Number 1. It was granted, and the controllers at the base knew, but when we flew a trip from Texas to Mississippi with that call sign and we had priority tasking the whole trip, cruising along at 9,000 ft and 120 knots. Good times.