You Do Need power plug adapter while traveling from Papua New Guinea to Falkland Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Falkland Islands is G and in Papua New Guinea is I. This is how they look like.

Papua New Guinea

In Papua New Guinea, outlets of type I are in use.

Type I

Falkland Islands

In Falkland Islands, outlets of type G are in use.

Type G