If you wish you can also air file a FPL......on departure call London Infrmation to file airborne flight Plan.......on arrival at private site in Scotland advise Scottish Info 119.875 that you wish to close your flight plan.......that said though why bother to file at all. Providing you call London info on departure they will hand you over to Scottish info as you cross the brder and you will maintain radio contact with Scottish till you descend to land at the private site....that way you stay safe and there is no need to hasle the system by fileing a plan.
