United States, 1912 (May 18) Driving Park Aviation Meet, Altoona, Penn. Violet "Aerial Post Office No. 1, Altoona, Pa., May 18, 1912" postmark on 1¢ red postal card (small tear at bottom), otherwise Very Fine, proposed flight was cancelled when police could not keep the crowds off the airfield. AAMC No. 24. Scott No. UX23  Estimate $50 - 75. $0 (Image)