These aircraft are kind of iconic given that they have a heavy press presence. Maybe they represent the current conflicts, Iraq and Afghanistan in the same way the Huey has come to stand for a certain view of America's war in Vietnam.

The Chinook itself has had a patchy history with the U.K armed forces, unreliability issues and the sheer expense of keeping them up to date. However as an image it seems to be a kind of visual shorthand for the British contribution to the war in Afghanistan.