A budgie that is clearflight pied will have all clear flight feathers. Sometimes also the major coverts (row of feathers above the flight feathers) and/or the tail feathers will also be clear. Usually a clearflight pied will have some small patches of clear body feathers up around the neck. Clearflight pieds also have a patch of clear feathers on the back of the head.

Basic Genetics:
Clearflight Pied - dominant
Normal - recessive
Details on clearflight genetics...

The clearflight pied variety has all clear flight feathers.

The clearflight pied variety also may have small patches of clear body feathers near the neck.