PHILLIPINE ISLANDS 1931, Dec 18, Cover "pioneer Flight", from Del Carmen via Fort Stotsenburg to Calcutta. Pair of 6 cts imperf., pair of 4 cts imperf. and one 16 cts perf. stamps, circular military, cachet in magenta, also in black 3 lines together with single line, army cachet label. On back six arrival stamps one "First Flight" circular in magenta, circlular in red by " Schweiz. Aerophilatelisten Verein". air
