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