The Supermarine Spitfire Mk. V (specifically the Mk. Vb) is a British fighter aircraft that holds historical significance as one of the most celebrated and effective Allied aircraft of World War II. It is a modification to the Mk. I variant armed with two Hispano-Suiza HS.404 autocannons (one in each wing) and four .303 Browning machineguns, with an upgraded engine which allows it to reach a speed of 589 km/h.