de Havilland Mosquito FB Mk XVIII
The Mosquito FB Mk XVIII (sometimes known as the Tsetse) was a fighter-bomber variant of the Mosquito, developed from the FB Mk VI. The initial prototype was converted from a FB Mk VI while 17 others were purpose-built. The Mk XVIII was armed with a Molins “6-pounder Class M” cannon: this was a modified QF 6-pounder (57 mm) anti-tank gun fitted with an auto-loader to allow both semi- or fully automatic fire. A total of 25 rounds were carried, with the entire installation weighing 1,580 lb (720 kg). In addition, 900 lb (410 kg) of armour was added within the engine cowlings, around the nose and under the cockpit floor to protect the engines and crew from heavily armed U-boats, the intended primary target of the Mk XVIII. Two or four .303 (7.7 mm) Browning machine guns were retained in the nose and were used to “sight” the main weapon onto the target.