The Loire 250 was built to meet a requirement for a single-seat fighter prototype to undergo a fly-off competition with the Dewoitine D.513 and Morane-Saulnier MS.405.[1] The Loire 250 was an all-metal low-wing monoplane powered by a 1,000 hp (746 kW) Hispano-Suiza 14Ha-7a radial engine with a single enclosed cockpit and retractable conventional landing gear with a tailwheel.[1] Only one prototype was produced; it first flew 27 September 1935. It was modified to improve performance before the fly-off but failed to gain a production order.[1] The prototype was unarmed but it was intended to fit two 20 mm cannon and two 7.5 mm machine-guns if the type entered production.[1]