Originally Posted by
SpringHeeledJack
A US Army CH-47 just gone slowly down the Thames making a wonderful racket. Do they have different engines compared to the RAF Chinooks ? Sounded very different, though maybe due to it's relatively slow speed whilst sightseeing.
Does the US Army still have the CH-47C variant in service?
If so, the sound difference may have been down to the CH-47C's metal rotor blades, compared to the composite blades on later variants, including the RAF's Chinooks.
Just a thought - I could be completely wrong, of course.