M M M M M 1926 SECOND INTER-ISLAND AERIAL MAIL SERVICE M
PI-9a NR JAN 05 MANILA CAPIZ CAPIZ, P.I.  REC'D  CAPIZ  JAN 5 3PM M
PI-9b NR JAN 05 MANILA CEBU CEBU, REC'D CEBU, P.I.  JAN 5 3PM M
PI-9c NR JAN 05 MANILA ILOILO ILOILO, P.I. REC'D ILOILO JAN 5 3PM M
PI-9d 9a JAN 05 MANILA SILAY SILAY, OCC. NEGROS REC'D JAN 9 _  Time not clear. Via Cebu
PI-9e NR JAN 05 MANILA SURIGAO SURIGAO, P.I. REC'D SURIGAO JAN 12 10AM  M
PI-9f NR JAN 08 MANILA DANSALAN DANSALAN, LANAO, P.I. JAN 13 5PM M
PI-9g 9d JAN 08 MANILA MASBATE MASBATE, P.I. REC'D. JAN 14 12M M
PI-9h 9c JAN 08 MANILA  SAN JOSE M
PI-9i 9b JAN 19 BATANGAS MANILA MANILA, P.I. REC'D. JAN 19 8:30PM M
M M M M M 1926 FIRST NORTHERN LUZON FLIGHTS M
PI-10a 10b JAN 31 MANILA SAN FERNANDO RT SAN FERNANDO, P.I. REC'D LA UNION FEB 1 9AM Less than 10 RT covers.
PI-10b 10a FEB 03 MANILA CORREGIDOR RT CORREGIDOR REC'D CAVITE FEB 3 1926 5PM Less than 10 RT covers.
PI-10c 10c FEB 03 MANILA APARRI RT APARRI, P.I. CAGAYAN REC'D / FEB 3 2PM 1926 Less than 10 RT covers.
PI-10d 10f FEB 03 CORREGIDOR SAN FERNANDO M M
PI-10e 10g FEB 03 CORREGIDOR  APARRI M M
PI-10f 10h FEB 03 SAN FERNANDO  APARRI M M
PI-10g NR FEB 04 CORREGIDOR  MANILA Returned Feb 4 M
PI-10h 10e FEB 09 SAN FERNANDO MANILA Returned Feb 9 M
PI-10i 10i FEB 09 APARRI  SAN FERNANDO M M
PI-10j 10d FEB 10 APARRI  MANILA Returned Feb 10 M
M M M M M 1926 FLIGHTS TO SOUTHERN ISLAND FLIGHTS M
PI-11 NR APR 16 MANILA CEBU With "RECEIVED BY AEROPLANE" postmark. M
PI-11a NR APR 17 CEBU ZAMBOANGA ZAMBOANGA, ZAMBOANGA APR 19 1926 10AM M
PI-11b NR APR 22 MASBATE MANILA MANILA, P.I. REC'D APR 23 2:30PM M
PI-11c 10AA APR 22 BATANGAS MANILA Backstamped on 8PM of the same day. M
M M M M MM 1926 MADRID - MANILA M
PI-12 11 MAY 13 APARRI MANILA MAY 13 M
FNC 11a MAY 13 STOTSENBERG MANILA MAY 13 Madrid-Manila escorts. Refer to PI-13
PI-12a 11b APR 05 MADRID MANILA MAY 13 M
PI-12b 11c MAY 13 MADRID  MANILA Postage Due Stamps M
PI-12c 11d APR 21 CALCUTTA MANILA MAY 13 M
PI-12d 11e APR 23 BANGKOK MANILA MAY 13 M
PI-12e NR MAY 02 SAIGON MANILA MAY 13 ONE COVER CONFIRMED TO EXIST
PI-12f 11g MAY 11 MACAO  MANILA MAY 13 M
M M M MM MM 1926 STOTSENBURG PIONEER FLIGHT M
PI-13 11a MAY 13 STOTSENBERG MANILA MAY 13 Pioneer flight to Manila
M 1926 SECOND NORTHERN LUZON FLIGHTS M
PI-14 12 JUN 08 MANILA APARRI APARRI, P.I. REC'D CAGAYAN JUN 9 11AM M
PI-14a 13 JUN 25 APARRI  MANILA MANILA, P.I. JUN 29 4PM M
PI-14b 14 JUL 15 APARRI  MANILA RECEIVED BY AEROPLANE cachet M
M M M M M 1926 SPECIAL MILITARY FLIGHTS M
PI-15 NR OCT 20 MANILA  STOTSENBURG RECEIVED BY AEROPLANE purple cachet TWO KNOWN
M M M M M 1926 RECON AND POSTAL EMERGENCY FLIGHTS M
PI-16 15 NOV 09 MANILA BATANGAS BATANGAS, P.I. REC'D. NOV 9 4PM. Either black or purple cachet
PI-16a 16 NOV 10 BATANGAS MANILA MANILA P.I. NOV 10 12M M
PI-16b NR NOV 15 TAYABAS MANILA MANILA REGISTRY SECTION NOV 16 7 FLOWN
NOTE ON PI-13 / AAMC 11a
The covers were not flown by the Legaspi to Manila but carried by one of her three U.S. Army Air Service escorts (two de Havilland DH-4 bombers and a third unidentified aircraft) to Manila.  The AAMC clearly state this fact and to my mind they should be listed separately as a pioneer flight, the first flight in fact from Stotsenburg to Manila. As shown in the example in this collection the purple cachet "Via Primer Correo Aereo /Madrid - Manila" and the two types of special flight cachets do not belong to the cover. This flight deserve to be listed separately as a credit to the U.S. Army Air Corps.

PI-15: This is the first documented flight ot Fort Stotsenburg.