QDM, the Alpha Charlie callsigns are Vigilant motor gliders operated by the RAF to provide air experience thgrough to solo flying for cadets. They usually only operate at weekends but are quite busy during the summer hols.
We are very happy to talk to you when you are on your way to Lundy - other than London Info or Cardiff (if you are high enough) there isn't anyone else in N Devon to provide any sort of service.