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 June 2005 with all aboard killed, including a 16-member U.S. Special Operations team. In May 2011, an Australian Army CH-47D crashed during a resupply mission in Zabul Province, resulting in one fatality and five survivors. The helicopter was unable to be recovered and was destroyed in place. To compensate for the loss, the ADF added two ex-U.S. Army CH-47Ds to the fleet which are expected to be in service until the introduction of the CH-47Fs in 2016. Since the type's inception, the Chinook has carried out secondary missions including medical evacuation, disaster relief, search and rescue, aircraft recovery, fire