United States 1934 Boris Sergievsky Giant Sikorsky S42 Test Pilot Signed Flight Cover

Cover franked with 8c Airmail, postmarked with Bridgeport duplex (Apr 26), with violet cachet of the Worlds Altitute Record / Seaplane / CAT With 2000 & 5000 / Kilo Load, signed "Boris Sergievsky" in black, wih signature of N.A.A. Observer below, to Pennsylvania, a pleasing cover signed by this WWI Flying Ace of Russia and subsequent Test Pilot.