The British Walkaround Inspection does not an American Preflight Inspection make!
I was looked at with great disdain when I began to open cowlings and the like and was told "that just isn't the done thing, mate!"
At some operations there was no need to even do the walkaround ( of either type) but at some it was amazing what could be found lurking within the cowlings.
On one occasion I pulled a full bed sheet out of a hidey hole underneath the tail rotor drive shaft on a Bell 212. The reaction to my demanding a proper inspection of the aircraft by the engineering staff was interesting to say the least....and not because it was based upon a lot of embarrassment or professional concern.
A second interesting event was looking over the aircraft after a tail rotor change and airtest and a signed release for flight (as indicated by the tech log) to see one of the tail rotor pitch change links dangling loose from one end.