Ka rere te tauira tuatahi ki Wright Field, Ohio, ki te whakataetae i roto i te USAAC rere-i runga i mo te toa kotahi-noho hou, engari i whakaroa te whakataetae no te mea i hinga te urunga Seversky i runga i tona ara ki reira. Whakamahia Curtiss te whakaroa ki te whakakapi i te pūkaha unreliable ki te Wright XR-1820-39 Cyclone whakaputa 950 hp (710 kW) me ki te mahi anō i te fuselage, tāpiri i te matapihi muri scalloped motuhake ki te whakapai ake i te tirohanga. whakaritea te tauira hou Model 75B ki te putanga R-1670 whakahuatia hoki Model 75D. te rere-i runga i te mutunga ka mau i roto i te April 1936. Heoi, kihai i taea e te pūkaha hou ki te whakarato i tona mana tohua, a ka tae anake te tauira rererangi 285 mph (459 km / h).
Ko te tau 1936