Interesting background on The Eiger Sanction & Clint Eastwood

From Wikipedia

Casting
The rights to the film were bought by Universal in 1972, soon after the book was published, and it was originally a Richard Zanuck and David Brown production. Paul Newman was intended for Jonathan Hemlock. After reading the script, Newman declined, believing the film too violent.[4] With concerns over early scripts, Eastwood contacted novelist Warren Murphy (known for his The Destroyer assassin series) in Connecticut in February 1974 for assistance despite his having never read the book or written for a film before.[5] Murphy read the novel and agreed to write the script but was not happy with the tone of the novel which he believed patronized readers.[5] A draft by Murphy emerged in late March and a revised script was completed a month later.[6] George Kennedy, who had recently finished filming Thunderbolt and Lightfoot with Eastwood was cast as Big Ben Bowman, Hemlock's friend and secret adversary, Jack Cassidy cast as Miles Mellough, and Thayer David as "Dragon." Vonetta McGee of Thomasine and Bushrod was cast as the African-American female C2 operative, Jemima Brown.[7]
[edit]Filming


The Eiger
In the summer of 1974, Eastwood travelled to Yosemite National Park where he was trained in mountain climbing by Mike Hoover, a mountaineering cinematographer, technical adviser, and an Academy Award-nominated professional mountaineer from Jackson, Wyoming.[8] Filming in Grindelwald, Switzerland began on August 12, 1974 with a team of climbing experts and advisers from America, England, Germany, Switzerland, and Canada.[7] The climbers were based at the Hotel Bellevue des Alpes at Kleine Scheidegg.[9] The Eiger at 13,041 feet is not as tall as other mountains in the Swiss Alps, but it is treacherous climbing.[N 2] Eastwood's decision to brave the mountain was disapproved by Dougal Haston, director of the International School of Mountaineering, who had lost climbers on the Eiger, and by cameraman Frank Stanley, who thought that to climb a perilous mountain to shoot a film was unnecessary.[9] According to cameraman Rexford Metz, it was a boyhood fantasy of Eastwood's to climb such a mountain, and he enjoyed displaying heroic machismo.[10]

A number of accidents occurred during the filming of The Eiger Sanction. A twenty-seven-year old English climber, David Knowles, who was a body double and photographer, was killed during a rock fall, with Hoover narrowly escaping with his life.[11] Eastwood almost abandoned the project but proceeded because he did not want Knowles to have died in vain.[12] Eastwood insisted on doing all his own climbing and stunts. Frank Stanley also fell but survived and used a wheelchair for some time.[13] Stanley, who completed filming under pressure from Eastwood, blamed Eastwood for the accident because of lack of preparation, describing him as a director and actor as a "very impatient man who doesn't really plan his pictures or do any homework. He figures he can go right in and sail through these things."[14] Stanley was never hired by Eastwood or Malpaso Productions again. Several other accidents and events apparently took place during the filming, but were hidden from the public by the producers.[12]

Speaking with Roger Ebert of the Chicago Sun-Times, Eastwood discussed the stunt in which he dangled from a mountain on the end of a cable:
I didn't want to use a stunt man, because I wanted to use a telephoto lens and zoom in slowly all the way to my face—so you could see it was really me. I put on a little disguise and slipped into a sneak preview of the film to see how people liked it. When I was hanging up there in the air, the woman in front of me said to her friend, 'Gee, I wonder how they did that?' and her friend said, 'Special effects.'[15]