In the 1930s, the United States military tasked Boeing with building a bomber that could fly over the frontlines, destroy the enemy’s infrastructure, and return to base safely; the result was the B-17 Flying Fortress. Manned by a crew of ten, the Flying Fortress could carry its 6,000-pound bomb payload 2,000 miles at a top speed of 300 mph. It was also equipped with thirteen .50 caliber Browning machine guns for protection against enemy fighters. During World War II, the Allies flew the B-17 in both the European and Pacific Theaters, though the Flying Fortress is primarily known for its daytime bombing raids over Germany. While the aircraft could sustain a lot of damage and still return to base, these bombing raids were deadly missions. However, once the Allies adopted the P-51 Mustang as a fighter escort, B-17 bombing raids became more effective, and the Allies were able to target Germany’s industry more effectively. Throughout the war, over 12,000 Flying Fortresses were produced. However, the B-17 became obsolete following the introduction of the B-29 Superfortress.