Boeing engine started in 1943 and Boeing's gas turbines were designated models 502 (T50), 520 (T60), 540, 551 and 553. Boeing built 2,461 engines before production ceased in April 1968. Many applications of the Boeing gas turbine engines were considered to be firsts, including the first turbine-powered helicopter and boat. Vertol Aircraft Corporation was acquired by Boeing in 1960, and was reorganized as Boeing's Vertol division. The twin-rotor CH-47 Chinook, produced by Vertol, took its first flight in 1961. This heavy-lift helicopter remains a work-horse vehicle to the present day. In 1964, Vertol also began production of the CH-46 Sea Knight.
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