A regular 'Troop' is expected to spend upwards of 30 weekends a year training on the hill. Many Himalayan expeditions have been mounted, and troops and ex-troops have participated in other organizations' expeditions. In 1970, ex RAF Kinloss troop Ian Clough died when a serac collapsed on him while descending Annapurna on an expedition with Chris Bonington. Other sites for expeditions have included Alaska's Denali, the first RAF single service ascent of Mt. Everest in 2001, and Antarctica, where troops have volunteered for British Antarctic Survey duties.