North American XP-82 “Twin Mustang” 44-83887 at Muroc Army Air Base, California. Official flight view of the “Twin Mustang”, the Army Air Forces long-range fighter. Powered by two 12-cylinder Allison V-1710 engines, the P-82 is capable of a top speed of over 475 miles per hour. Rate of climb for the aircraft is over 5000 feet a minute. Standard armament is six .50 caliber machine guns, but the P-82 can also carry eight additional guns in a special center nacelle.