Some months ago it was claimed by some instructors, that a flight commencing from an unlicensed aerodrome, could start instruction for a licence or aircraft rating, by touching wheels at a licensed aerodrome however; on completion of the instruction, it was then only necessary to overfly the licenced aerodrome en route to the unlicensed aerodrome!
The cost of operating form an unlicensed site is obviously so much less, that the ferry can be conducted free of charge!
An interesting question arrises with government aerodromes; CAA legal department advises that they must be under operational control of a Service, Govt Dept or Foreign power; not simply owned by them.
The CAA are again looking at the possibility of allowing unlicensed aerodromes to be used for training. It was offered on a plate in 1996 but rejected by the Industry; of the 2500+ interested parties consulted, only 125 bothered to respond, the majority of which were aerodrome operators.