The A8V1 Type S Two Seat Fighter was an aircraft operated by the Imperial Japanese Navy Air Service.

When the USAAC announced a competition for a new single-seat fighter in 1935, Seversky sent the SEV-2XP, confident it would win despite being a two-seater.

The Air Corps delayed the fly-off until March 1936, which allowed Seversky time to rework the fighter into the single-seat SEV-1XP with retractable landing gear and re-engined with the Wright R-1820 radial.

Two demonstrators ended up in the USSR; although a manufacturing licence was also bought, the Soviets undertook no production.

Sweden ordered 52 2PAs (known as the B 6), but only two were delivered before the remaining 50 were impounded in 1940 and put into service with the USAAC as the AT-12 Guardsman advanced trainer.