Cover franked 1921 4d black & red on yellow & 1/- orange brown GV issue (SG 101 & 103) tied by CASTRIES 1st AIR MAIL ST LUCIA circular cancels with CASTRIES cds dated 25 Sept 1929 alongside. Flown on the St Lucia - St. John's, Antigua first flight. Addressed to the US Consul in ST JOHN'S, ANTIGUA with arrival cds on reverse. (Muller #4, only 251 covers were carried)