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
Boeing CH-47 Chinook In February 2010, the USAF announced plans to replace aging HH-60G helicopters, and deferred secondary combat search and rescue requirements calling for a larger helicopter. The Royal Air Force version of the CH-47C is designated Chinook HC1; its versions of the CH-47D are designated Chinook HC2 and HC2A. The export version of the CH-47C Chinook for the Italian Army was designated "CH-47C Plus". The HH-47D is a search and rescue version for the Republic of Korea Air Force. The CH-47DG is an upgraded version of the CH-47C for Greece. While the CH-47SD (also known as the "Super D") is a