 The Boeing Chinook is a tandem rotor helicopter operated by the Royal Air Force ( RAF ) . A series of variants based on the United States Army 's Boeing CH @-@ 47 Chinook , the RAF Chinook fleet is the largest outside the United States . RAF Chinooks have seen extensive service including fighting in the Falklands War , peace @-@ keeping commitments in the Balkans , and action in the Iraq and Afghanistan wars . 
