A twin-engine monoplane fighter-bomber of wooden construction, originally conceived of as a multi-purpose high-speed scout-bomber. The DH.98 completed its first flight on November 25, 1940. Mass production began in October of 1941, and the first production models entered the service of the RAF in November of the same year.
The prototype Mosquito FB.Mk.VI was based on the F.Mk.II, nicknamed the “Intruder”, with strengthened armament. It first flew on June 1, 1942, and the plane saw its first combat in February of 1943.
The first series of Mosquito FB.Mk.VI Srs.1 planes (300 airplanes) was equipped with a liquid cooled engine, the Rolls Royce Merlin Mk.21, Mk.23, or, later, the Mk.25. The planes were armed with four fuselage-mounted 20mm British-Hispano Mk.II cannons and four 7.7mm Colt-Browning .303 Mk.II machine guns. In addition, the plane inherited the F.Mk.II's capacity for carrying two 250 lb (113 kg) bombs in the underwing pylons. The internal bomb bay was completely filled with the plane's weaponry and an extra fuel tank.
The FB.Mk.VI Srs.2, the second production series, was fitted with the Merlin Mk.25 engine, guaranteeing the best possible performance characteristics in low and middle altitude conditions. The internal fuel tank was removed so that the plane could carry 250 lb bombs in its internal bomb bay, plus two 250 or 500 lb (227 kg) bombs carried externally. Instead of bombs, extra fuel tanks could be mounted under the wings, carrying 50, 100, or 200 gallons (227.3 liters, 454.6 liters, or 909.2 liters) of fuel, or 8 unguided 25 or 60 lb rockets. The plane's cannons and machine guns remained unchanged.
The FB.Mk.VI saw its first combat on October 3, 1943. The plane was widely adopted to make accurate strikes on especially important targets. From 1944 on, the FB.Mk.VI was used by the RAF Coastal Command and saw action over the Bay of Biscay, the North Sea, the English Channel, and over the rivers of France, Belgium, and Germany.
The FB.Mk.VI was the most produced of all of the planes built during the war. Factories managed to produce 2,584 planes. All in all, 6,710 Mosquitoes (from all series) were produced. According to General Bennett, the only drawback the planes had was that there were never enough of them. Great Britain removed the Mosquito from service from 1947 to 1950.