You Do Need power plug adapter while traveling from American Samoa to United Kingdom (UK).

Here is Why You Need An Adapter

The outlet and plug type used in United Kingdom (UK) is G and in American Samoa are A, B, F and I. This is how they look like.

American Samoa

In American Samoa, outlets of type A, B, F and I are in use.

Type A

Type B

Type F

Type I

United Kingdom (UK)

In United Kingdom (UK), outlets of type G are in use.

Type G