A 35 year old man had started up Jack's Rake, alone, after his friends had, wisely, declined his invitation to go with him. After a short distance he tried to climb down again, but was unable to, because of the ice. He continued up, and slipped, dislocating his kneecap, and injuring his back. Mobile phone calls from the area gave us the impression that he was only just able to hang on. Members of RAF Leeming MRT were in the area and they were able to get to him before us, and stabilise him. He was then airlifted to hospital by RAF Boulmer.