 The US Army 's next generation Chinook , the CH @-@ 47D , entered service in 1982 . Improvements from the CH @-@ 47C included upgraded engines , composite rotor blades , a redesigned cockpit to reduce pilot workload , redundant and improved electrical systems , an advanced flight control system ( FCS ) and improved avionics . The RAF returned their original Mk1s to Boeing for upgrading to CH @-@ 47D standard , the first of which returned to the UK in 1993 . 
