The Avro Lancaster is a British heavy bomber that played a crucial role during World War II. Developed by Avro in the early 1940s, the Lancaster became the RAF's primary strategic bomber, renowned for its impressive payload capacity and operational versatility. Powered by four Rolls-Royce Merlin engines, the Lancaster could achieve speeds of up to 454 km/h, and carry up to 6,400 kg of bombs, including a number of experimental superheavy bombs such as the Grand Slam earthquake bomb. The aircraft's defensive armament included eight Browning M1919 .303 British machineguns in nose, dorsal, and tail turrets. Its combination of range, payload, and adaptability made the Lancaster a key asset in the Allied strategic bombing campaign, particularly against France.