Qalabkii ugu horreeyay wuxuu duulay 6 May 1935, isagoo gaaray 281 mph (452 km/h) 10,000 ft (3,000 m) intii lagu jiray duulimaadyadii tijaabada hore. 27 May 1935, nooca ayaa loo duulay Wright Field, Ohio, si uu ugu tartamo USAAC duulimaadka duulimaadka hal-kursi cusub, laakiin tartanka ayaa dib loo dhigay sababtoo ah Seversky ayaa ku burburtay jidka halkaas. Curtiss wuxuu ka faa'iideystay dib u dhaca si uu ugu beddelo mashiinka aan la isku halleyn karin Wright XR-1820-39 Cyclone oo soo saara 950 hp (710 kW) iyo in dib loo cusbooneysiiyo jirka, isagoo ku daray daaqadaha gadaal ee kala duwan si loo hagaajiyo aragtida. Nooca cusub waxaa loo magacaabay Model 75B iyadoo nooca R-1670 loo magacaabay Model 75D.
Sanadkii 1936