You Do Need power plug adapter while traveling from Christmas Island to Chad.

Here is Why You Need An Adapter

The outlet and plug type used in Chad are C, D, E and F and in Christmas Island is I. This is how they look like.

Christmas Island

In Christmas Island, outlets of type I are in use.

Type I

Chad

In Chad, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F