The only country the begins with the letter 'W' with airmail issues that I can think of is the Wallis & Futuna Islands in the Pacific Ocean near New Caledonia. Up until 1955, their airmail stamps consisted of French colonial omnibus key types inscribed 'WALLIS ET FUTUNA' and one set from New Caledonia with 'WALLIS ET FUTUNA' overprinted in blue.
I posted a similar question on the Cook Islands forum. Does anyone have information on the history of the Polynesian Airlines souvenir covers flown by Nelson Eustis around the various island groups back in 1966 and newer. I have some from 1979 is the newest one I have purchased.