I'm a GA pilot. NATS implemented an optional online systen that covered at least Luton & Stansted whereby one could pre-notify an intention to route into the Class D airspace either for transit or to a destination inside the zone. It was great. You called, the controller replied that he/she had your details and thereafter the amount of RT traffic was minimal. Regrettably my understanding is that is has been discontinued. Would wider use of such a system help manage itinerant traffic?