Back in the early 70s I went gliding at the Cairngorm Gliding Club at Feshiebridge between Aviemore and Kingussie. Lovely part of the world with a ridge running paralell to the runway so with the wind blowing on to the ridge (which it did quite a lot) you could get a quite reasonable time in the air with the winch launch they used at the time.
One day, most of us were lazing on the ground watching the T-21 beating up and down the ridge when we heard a jet. A Canberra came up the valley, passed beneath the glider and continued on his merry way. No bunt, no panic, just happened.