CANADA 1928,  Scott 142, CL42 on 1928 Yukon Airways First Flight Cover.  First Flight, Carcross to White Horse, Yukon.  3 strikes of CARCROSS / AP 13 28 / YUKON CDS, 2 of which tie 25c blue Yukon Airways & 2c green Confederation to First Flight envelope.  Reverse: WHITE HORSE / AP 16 28 / YUKON receiver CDS.  Canadian Air Mail Catalogue CL42-2801f