Entry requirements are (typically!):
1. Being prepared to give up every Saturday or Sunday to go flying! (Allowing for holidays!!)
2. Expecting not to always fly and being prepared to help out on the school, like driving cadets around, cleaning the HQ, doing paperwork, etc, etc.
3. Passing RAF Gliding Instructors medical. It's about the same level as a class 1.
4. Satisfying the VGS Commanding Officer that you are worth training! ie. not going to turf off to the nearest airline once you have got enough hours!
There are lots of VGS throughout the UK and you can find the nearest to you by looking up Air Cadets in the phone book and give them a call.
It's the best flying I have ever done and you get taught to fly and teach to a very high standard.
All the best,
Vigi