Unlikely Survivor: Northrop’s N-9MB
Atruly unique and pioneering aircraft, the Planes of Fame Air Museum’s Northrop N-9MB is the only survivor of a World War II program intended to provide the U.S. Army Air Forces with an intercontinental bomber employing Jack Northrop’s revolutionary flying-wing concept. The last of four 1/3-scale development aircraft (a 60-foot wingspan) intended to investigate various aspects of the flight-control systems that would be used in the 172-foot wingspan bombers, the N-9MB flew for the first time in 1944. It was the first airplane to use a fully hydraulic flight-control system with airspeed-sensitive feedback. The other 1/3- scale Northrop flying-wing development aircraft were two N-9Ms (the first of which took to the air for its initial flight on December 27, 1942) and the N-9MA. The N-9Ms and the N-9MA were powered by a pair of 275hp Menasco C-6S-4 6-cylinder, air-cooled inline engines, while the N-9MB flew with a pair of 300hp Franklin 0-540-7 6-cylinder, air-cooled opposed engines. With the engines in pusher configuration, the N-9Ms featured steel-tube center sections covered with wood and metal panels, and wood outer-wing sections. They had tricycle landing gear with an extended, retractable tailwheel bumper to prevent damage to the propellers on takeoff rotation.
The N-9M made about 50 flights for a total of 30 hours in the air before being lost in early 1943 in a fatal crash, possibly due to aerodynamic forces inducing full-aft pressure on the control column. The remaining three N-9Ms flew successfully, however, for hundreds of hours in a three-year program that provided valuable information for the Northrop B-35 Flying Wing bomber (the prototype of which flew for the first time on June 25, 1946). They also provided prospective flying-wing bomber pilots with experience in the handling characteristics of flying-wing aircraft.
A program steeped in controversy, the piston-powered B-35 and jet-powered B-49 Flying Wings were advanced for their time and the subject of legend. At one time, as many as 270 of the big bombers (including prototypes and development aircraft) had been ordered in nine distinct variations. The piston-powered B-35s had four 3,000hp Pratt & Whitney R-4360-17 Wasp Major engines in pusher configuration, while the jet-powered B-49s came in eight- (4,000-pound thrust Allison J-35-A-15 turbojets) and six-engine (5,600-pound thrust Allison J-35-A-19 turbojets) configurations. It appears, however, that only 28 of the bombers were actually built or under construction, and only six of them ever flew (two XB-35s, one YB-35, two YB-49s, and one YRB-49A) before the majority of the program
was canceled on October 29, 1949, although work did continue on the sole YRB-49A reconnaissance variant until 1951. All the aircraft involved in the
Flying Wing bomber program were ordered to be scrapped, with the YRB-49A being the last to go, in October 1953.
The N-9MB somehow survived the scrapping order, however, and was eventually obtained by Edward T. Maloney, founder of the Planes of Fame
Air Museum, in the 1950s. The remains of the largely wooden airplane languished for three decades before a team of museum volunteers began the daunting task of restoring the historic aircraft to flying condition in 1981. After 13 years of dedicated work, the restored N-9MB made its first taxi test at the airport in Chino, California, on November 6, 1994, and its first public flight at Chino on November 11, 1994. The pilot for the Flying Wing’s early flights was Don Lykins, the museum’s chairman of the board, but
Ron Hackworth, director of the N-9MB’s restoration effort, became its primary pilot for the next two decades. Airline pilot and museum volunteer David Vopat is now the Flying Wing’s primary display pilot. The N-9MB is a regular participant in the annual Planes of Fame Airshow at the Chino Airport, and frequently flies at other events as well, some as far as 500 miles away. With its bright yellow-and-blue color and unique configuration, the N-9MB stands out wherever it goes.
Ron Hackworth flying the restored Northrop N-9MB over Southern California.
Don Lykins performed the test flights of the restored N-9MB and was even allowed to work from a hangar at Edwards Air Force Base for three days during the high-speed portions of that test program, intended to revalidate Jack Northrop’s work. (This photo was taken over the normally dry lake at Edwards AFB, which was flooded with winter rainwater at the time.)
Left: The cockpit of the restored N-9MB.
Above: Volunteers of the Planes of Fame Air Museum work on the restoration of the N-9MB. Almost all the badly rotted wood airframe had to be re-created, with the deteriorated parts used only for patterns.