25 June 1946: Northrop Corporation experimental test pilot Max R. Stanley and flight engineer Dale Schroeder made the first flight of the Northrop XB-35 “Flying Wing”, serial number 42-13603, from the factory’s airfield at Hawthorne, California, to Muroc Army Air Field (now, Edwards Air Force Base). The initial flight lasted 55 minutes.
The Los Angeles Times reported:
On June 25, 1946, Stanley piloted the first Flying Wing, the B-35, which was a four-engine 172-foot-long, boomerang-shaped craft, from Northrop’s Hawthorne Airport to what was then the Muroc Army airfield east of Palmdale.
Emerging from the cockpit after the 55-minute flight, Stanley told The Times: “She handled beautifully.”
But taxiing along the rabbit-infested Hawthorne runway, he had had momentary doubts, he conceded 50 years later: “I looked out and I was not gaining speed on this rabbit. I thought, either something’s wrong or that’s one hell of a fast rabbit.”
The XB-35 was designed as an aerodynamically efficient heavy bomber. It had a length of 53 feet, 1 inch (16.180 meters), a wingspan of 172 feet (52.426 meters) and overall height of 20 feet, 1 inch (6.121 meters). The wing was 37 feet 6 inches (11.430 meters), front to back, at the center, and tapered to 9 feet (2.743 meters) at the tips. The total wing area was 4,000 square feet (371.61 square meters). The prototype weighed 89,560 pounds (40,623.7 kilograms) empty, with a gross weight of 180,000 pounds (81,646.6 kilograms).
It was powered by four 4,362.5 cubic-inch-displacement (71.489 liter) air-cooled, supercharged, Pratt & Whitney R-4360-17 and -21 Wasp Major four-row 28-cylinder radial engines producing 3,000 horsepower each, mounted completely inside the wing. A drive shaft turned dual contra-rotating three-bladed propellers in pusher configuration at the wing’s trailing edge. (These were quickly changed to four-bladed propellers which were smoother in operation and more efficient.)
The XB-35 had a cruising speed of 183 miles per hour (295 kilometers per hour) at 39,700 feet (12,100 meters) and maximum speed was 391 miles per hour (629 kilometers per hour) at 35,000 feet (10,668 meters). With a crew of nine, and another six relief crewmembers, the bomber had a range of 8,150 miles (13,116 kilometers). The production version would have been armed with twenty .50-caliber machine guns for defense and could carry a maximum bomb load of 51,200 pounds (23,223 kilograms).
The XB-35 was plagued by unresolved problems with the propeller gear boxes which eventually forced Jack Northrop to ground the aircraft until the engine and propeller manufacturers could come up with a solution. The best solution was to change from piston to jet engines, and that version became the YB-49. Because of the continuing problems, though, 42-13603 was grounded after only 19 flights, and with its sister XB-35, 42-38323, was scrapped in August 1949.
© 2015, Bryan R. Swopesby