Nazarin ya nuna cewa guda tsaye stabilizer bai isa ba a high kusurwoyi na hari, kuma shi ya canza zuwa biyu tsaye stabilizers, canted a 45 °, sakamakon a cikin wani "sanyi longitudinal kwanciyar hankali" zane, wanda ya inganta maneuverability. Northrop ba tukuna m a cikin tashi-by-waya controls da kuma riƙe mechanically-signalled jirgin controls. A sakamakon jirgin sama, unveiled a kan 28 Janairu 1971, tallace-tallace a kalla nauyin 40,000 lb (18,144 kg) da kuma iyakar gudun Mach 2, amma stirred kadan sha'awa tsakanin kasashen waje buyers. The farko samfur (serial lambar 72-156 mph) da aka mirgine fita a Hawthorne a kan Afrilu 4, 1974; da farko jirgin a Edwards AFB ya zo a kan Yuni 9 da "Hute" Henry Choute a controls ya kai 61 minti na tashi a tsawo na 18,000 feet da kuma iyakar gudun 610 km / h. A watan Agusta 1974, General Chow ya lura cewa, "A lokacin da jirgin saman na farko ya tashi a wani mataki na sama sama na 93 °, ya iya kai iy
21 ga watan Agusta