Helicopter flight controls blades collectively ("i.e.," all at the same time) and independent of their position. Therefore, if a collective input is made, all the blades change equally, and as a result, the helicopter increases or decreases its total lift derived from the rotor. In level flight this would cause a climb or descent, while with the helicopter pitched forward an increase in total lift would produce an acceleration together with a given amount of ascent. The collective pitch control in a Boeing CH-47 Chinook is called a "thrust control", but serves the same purpose, except that it controls two rotor systems, applying
Chinook (dog) occurs in about 10% of all male dogs. The Chinook owes its existence to one man: Arthur Treadwell Walden of Wonalancet, New Hampshire. The breed derives principally from one male ancestor born in 1917, named "Chinook", who was Walden's lead dog and stud. "Chinook" derived from a crossbreeding of husky stock from the Peary North Pole expedition with a large, tawny Mastiff-like male. Photos of "Chinook" show a drop-eared dog with a broad Mastiff head and muzzle. Walden's leader was bred to Belgian Sheepdogs, German Shepherd Dogs, Canadian Eskimo Dogs and perhaps other breeds; the progeny were bred back to