During the war, U.S. pilots were given a packet of Philippine currency as a part of thier survival kit, should they be shot down.  The packets consisted of (4) 10 Peso notes, (4) 5 Peso notes and (40) 1 Peso notes (100 Pesos total).

All of these 'Aviator notes' are dated 1941. The 1 Peso notes have serial numbers from E6324001E - E6524000E.  The 5 Peso notes are numbered from E1328001E - E1348000E and the 10 Peso notes range from E870001E - E890000E.