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 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