Dean Potter was a free spirit, his strong urge for freedom always got him into trouble. Potter was known for his free solo ascents and base jumps. When Potter was once again in Grindelwald, he decided to try his base jump with dog Whisper. He climbed via the Eiger glacier through the western flank to the “mushroom” on the Eiger and from there he jumped down with his dog in his backpack. This action resulted in the short film “When dogs fly”. Dean Potter managed the longest duration of a base wingsuit flight: in 2 minutes and 50 seconds he flew almost 6.5 km from the Eiger. In May 2015 Potter was killed in an accident during a base jump in Yosemite national park.