Coverage of a project at Dugway Proving Ground, Utah to determine the most effective means for destroying Japanese-type fortifications. A typewritten report on the subject. A United States Army Air Force ( USAAF ) B-25H Mitchell bomber aircraft in a 75mm cannon attack. The target on the ground is marked with a white circle. Smoke rises from the attacks on the ground. Ground fire controllers at radio equipment. A USAAF P-38 Lightening plane in a bombing attack. (World War II period).