1929 (2 Mar) two flown covers from Warszawa to Lwow, each attractively franked with a combination of Air Post and L.O.P.P. labels, fine-v.f. (Image)

Est.US$150

1929 (8 July) first flight cover from Katowice to Venice, corresponding cachet, transit (Vienna) and arrival pmk, some toning (Image)

Est.US$150

1931 (20 July) first flight from Sofia (Bulgaria) to Gdynia, v.f., with 21.7 Warszawa transit and 22.7.31 Danzig arrival pmks, returned to sender, v.f., only five (!) carried (Image)

Est.US$500

1931 (20 July) first flight from Sofia (Bulgaria) to Warszawa, v.f., with 21.7 arrival pmk, charged 10gr postage due (deemed unnecessary, hence "Uniewazniono" (cancelled) hs applied), only five (!) carried (Image)

Est.US$500

1934 (27 June) cover with U.S. and Polish franking, special cachet and signed by both Adamowicz brothers, v.f., also with a news photo of the NR 797-W plane. On June 28, Benjamin and Joseph Adamowicz took off from Floyd Bennett Field in NYC and landed in Harbour Grace, Newfoundland. The next day, they took off from there for a Trans-Atlantic trip. Through mechanical problems, leaking engine and heavy rainstorm, they managed to reach Europe (near Caen in France). The next day, after repairing a landing gear, they took off to Paris, then to Germany, where they were forced to land due to fuel leaks. On July 2, the brothers arrived in Warsaw, Poland, treated as heroes. The Adamowicz brothers were possibly the first amateur pilots in the world to fly a plane across the Atlantic (Image)

Est.US$150

1936-37 first flight covers from Warszawa to Tel Aviv and Jerusalem, each with corresponding cachets and arrival pmks, v.f., signed Gryzewski (Image)

Est.US$100

1939 Balloon Flights, 28 May, 11th Contest for Col. A. Wankowicz Cup, five covers, each with a different Balloon cachet, "Sanok", "Syrena", "Moscice", "Mestwin" and "Gryf", addressed to Gdynia, with Postage Due handstamped on arrival, fine-v.f. (Image)

Est.US$150