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 Pass Chinook Pass Chinook Pass (elevation 5430 ft./1656 m.) is a pass through the Cascade Range in the state of Washington. The pass provides the east entrance to Mount Rainier National Park, and carries State Route 410 between the towns of Enumclaw and Naches. Because of the high elevation, Chinook Pass is usually closed in November due to very heavy snow and significant avalanche danger. It usually opens in mid May and is not uncommon to have a snow depth at the summit of up to 15 feet. As part of the All-American Road program, Route 410 through Chinook Pass has