Sale 707 The Knapp Collection of Airmail Flights

U.S. and Foreign, 1926-80, endurance flights, approximately 390 covers in four albums, some better include signed photo of Augustus Post aviator & balloonist, 1926 Experimental Flight World Altitude Record postal card, 1925 Pulitzer Trophy Race postal card, 1929 U.S. Army Air Service Refuelling Mission, 1929 cover signed by Carl Spaatz, winner of Distinguished Service Cross, Elwood Quesada signed lettersheet for the "Question Mark", signed cover by Reg Robbins & James Kelly, 1929 signed cover by L.W. Mendell & R.S. Reinhart, cover signed by Anthony Fokker aircraft designer, 1930 glider flight cover, 1930 Women Pilot Day cover, 1932 Endurance Flight cover signed by Louise Thaden & Frances Marsalis, two 1934 Sikorsky Giant Flying Boat, 1935 Douglas "Mystery Ship" cover, also augmented by picture postcards, original photos, newspaper & magazine articles, tickets and signed ephemera, an exceptional collection not soon duplicated, a careful inspection will confirm this lot's true value, Fine to Very Fine.
Estimate $2,000 - 3,000.