Jack Northrop never went to college, but his strict work ethic, incredible drive, and unwavering ambition trumped his lack of formal education. He was a visionary who became a giant in aviation, familiar today as the Northrop in Northrop Grumman. But he never saw his pet project come to life, the flying wing aircraft whose whole body was a lifting surface. With minimum drag and maximum lift, he imagined the radical design becoming an efficient long-range bomber. The first true flying wing took flight in the mid-1940s, and within half a decade all were gone from the skies. Not until seven years after his death did Northrop’s flying wing really take off, becoming the asset to the US Air Force he knew it could be.
Jack Northrop before Northrop
John “Jack” Knudsen Northrop was born in 1895, before heavier than air flight became commonplace. But it wasn’t long after the skies began filling with airplanes that he became captivated by aviation; in 1911, he watched a pilot fly a pusher biplane over Santa Barbara. Five years later he was working for Loughead Aircraft (better known by its phonetically rebranded name, “Lockheed”), developing flying boats and designing wings during the First World War.
But he was also working on one of his own projects. The S-1 single-place biplane had a monocoque fuselage and folding wings, an overall ingenious design that was well ahead of its time when it was unveiled in 1919. But innovation came at a price. Each S-1 cost $2,500, an amount few were willing to pay in a market flooded with cheap war surplus planes selling for as little as $400. Northrop’s plane ruined Lockheed, and he moved to Douglas Aircraft in the early 1920s where he built “Round-the-World” cruisers and devoted his spare time to his new pet concept of an all-wing aircraft.
In the nearly two decades that followed, Northrop undertook a handful of successful business ventures, including reviving Lockheed Aircraft and developing the record-shattering Vega airplane for the company. In 1938, he formed his own company, Northrop Aircraft, based in Hawthorne, California. He intended for it to be an aviation research and development company, but the Second World War intervened.
The XB-35, the Flying Wing
Like many smaller aviation firms, Northrop found his company contributing to the war effort by building components of other companies’ aircraft while only managing a handful of its own projects. But that changed on November 22, 1941, when the US Army Air Force (AAF) initiated Project MX-140. The idea was to develop a high altitude, long range, heavy bombardment aircraft. Northrop won the contract, and it was exactly the project Jack Northrop needed to get his flying wing off the drawing board.
The aircraft was called the XB-35, and it was a flying wing; it was designed without the familiar central fuselage and rear tail. It was also massive, its 172-foot wing span promised to dwarf the wildly popular B-17 Flying Fortress, which was just over 104 feet across. And it included a host of new technical developments. Northrop’s flying wing boasted power operated elevons and rudders, which necessitated attaching springs to the control wheels and under the rudder pedal to give the pilot a “feel” for his control surfaces. Ram air pressure in a bellows attached to the control columns gave the pilot the same “feeling” of his elevator control. On the plane’s exterior, trim flaps, elevons, landing flaps, and split flaps for rudders were arranged along the trailing edge, the rear width of the wing. It also used wing tip slots with automatically controlled covers for increased longitudinal stability at high angles of attack.
Even without a central fuselage, the XB-35 had an impressive artillery capacity. Eight bomb bays were built into the wing allowing it to carry 10,000 pounds of conventional bombs. It also had twenty 0.50 calibre machine guns in seven turrets — four on the wing, two on the crew nacelle, and a tail stinger — for mid-air defence. The only traditional thing about the design was the engines. The wing was powered by four Pratt & Whitney Wasp Major 3,000 horsepower piston propellor engines.
And though the aircraft was nothing but wing, there was still ample space for a crew. The pilot sat in a plexiglass bubble left of centre with the co-pilot to the right and below him. Stations for an engineer, a radio operator, navigator, bombardier, and gunners were also in the forward part of the body. There was even room for a relief crew of six to sleep, a necessity given the design requirement of a 10,000 mile range on long-duration flights. It really was shaping up to be wholly unlike anything else in the skies at the time.
The Flying Wing Takes Flight
The original 1941 contract had called for one XB-35, but it was amended before long to include a second aircraft as a backup. In late 1942, thirteen service test models designated YB-35s were added to the contract, and by June, the final number of production XB-35 bombers was raised to 200. But Northrop couldn’t meet this demand, even when the Army Air Force brought the Glenn L. Martin Company in to help with the program. The partnership proved more of a hindrance than a help. There was confusion over the “X” and “Y” designations, a marked lack of coordination with other ongoing programs by both companies, and an overall loss of engineers to the draft. When the AAF reviewed the program in May of 1944, the decision was to cancel it.
The XB-35 became a post-war project, and this new designation brought a silver lining to the program. As WWII drew to a close, air forces on both sides of the conflict were using turbojet engines in their aircraft. It was clear that propellor planes like the XB-35 would soon become obsolete, but this new technology opened the door for a turbojet version of the flying wing.
Work on the XB-35 moved ahead in spite of this massive technological shift on the horizon. On May 16, 1946, the first wing taxied down the runway under its own power to give Northrop test pilot Max Stanley a safe way to get a feel for the controls. After dozens taxi tests in the month that followed, the XB-35 lifted off from the runway in front of a small gathered crowd on June 25. Stanley reached a top speed of 200 miles per hour on a 44-minute test flight from the Northrop Airport to the Muroc Army Air Base.
That first flight was dogged only by the erratic movement of one propeller governor, the mechanism that changes the propeller blades angle to maintain a selected speed as the aircraft flies through varying conditions. The governor problem didn’t go away on later flights, and was compounded by other problems. Stresses from counter-rotating propellers led to fatigue issues that in turn forced slower flights.
On to the Next One: the YB-49
While the XB-35 program moved forward, the AAF decided to pursue an experimental jet-powered version of the flying wing. And in an attempt to keep production costs down, the decision was made to convert existing aircraft to their jet-powered versions rather than build completely new aircraft. And so two B-35s then under construction were converted to YB-49s. Eight jet engines replaced the four propellor engines, vertical fences and fins were added for stability, and two of the bomb bays were converted to fuel tanks.
It was far from a perfect aircraft. Though sleek and manoeuvrable, the YB-49s range was far less than the original flying wing contract specifications. Another problem was its relatively small bomb bays. The XB-35 had been designed to hold WWII era bombs, not larger post-war versions. The larger bombs demanded the bay doors remain partially open in flight, adding significant drag, the very thing Northrop had been keen to eliminate with the flying wing design.
In spite of these issues, production moved forward and the first YB-49 was rolled out in Hawthorn on September 29, 1947. A month later on October 20, Max Stanley was again at the controls for the first taxi test. The very next day, the pilot took the jet-powered wing on its maiden flight, another run from Hawthorn to Muroc. It was an uneventful 34 minutes in the air.
From there, test flights began in earnest with a mix of failures and successes. There were technical problems with the auxiliary power units that supplied a current to the electrical system as well as with the still new jet engines. The YB-49 also revealed stability problems that threatened to rob the aircraft of its intended purpose of precision bombing. Offsetting these failures were successful flights. On April 26, 1948, the YB-49 stayed aloft for 9.5 hours, and two-thirds of that time was spent at an altitude over 40,000 feet.
Death of the Airmen and the Dream
By June of 1948, the YB-49 had racked up 24 flights totaling 57 hours in the air, all of them encouraging for the Northrop team. On June 5, the 25th flight left Muroc for a performance test. In the cockpit was pilot Major D.N. Forbes and his co-pilot Captain Glen W. Edwards. Also on board was flight engineer Lieutenant E. Swindell and two observers, Mr. C. Leser and Mr. C. LaFountain.
The crew followed its flight plan, tracked from the ground via position reports made at routine intervals over the Antelope Valley test range confirming the aircraft’s progress. Then, 20 minutes after one check-in, the YB-49’s remains were found scattered across the desert floor. The wing’s main portion was inverted and looked as though it had fallen almost straight down; the impact showed no indication of horizontal velocity at the moment of impact. It was also clear that the aircraft’s remains had caught fire, destroying a significant amount of evidence at the site. It was an impossible crash to survive. All five crew members died.
Eventually more debris — outer wing panels and elevator parts — were found in a narrow swath extending three miles from the crash site, but none of it was able to conclusively point to what had brought down the flying wing. It was obvious the YB-49 had suffered a major structural failure, and an eyewitness reported seeing the wing tumbling around its lateral axis just before hitting the ground. The most conclusive evidence suggested the fuselage had been stressed beyond its limits during a high-G manoeuvre, possibly recovering from a stall. Overstressed, the aircraft broke apart.
The loss was marked a year and a half later. On December 5, 1949, Muroc was renamed Edwards Air Force Base in honour of Captain Edwards.
But incredibly, the fatal crash didn’t kill the YB-49 program, though it didn’t last much longer. In early 1950, the remaining YB-35s midway through transitioning to YB-49s were scrapped, leaving just one active flying wing. On March 15 of that year, this last plane was destroyed in a fire following a high-speed taxi accident. The program was canceled, and the dream of the flying wing seemed to die at the same time.
Vindication for Northrop
During the Second World War, pilots dropped chaff or window to mask their aircraft’s position. The chaff created a cloud of thin pieces of aluminium, metallized glass fibre, or plastic that deflected radio or microwaves, scattering the signal so an enemy tracking station couldn’t pinpoint a plane’s true location. It was fairly effective, but 25 years later in the mid-1970s, the US Air Force was looking into a whole new way to avoid detection in flight. Stealth aircraft avoid detection by the same principle though by very different means. They hide behind irregular shapes, angular fuselages that deflect radio and microwaves, stopping the signal from getting back to its source. Rather than scattering the return signal, the signal doesn’t return to its source at all. The plane still shows up on radar tracking screens, but it will look more like a bird than a bomber, easily dismissible by a radar operator.
This push for stealth aircraft yielded the Advanced Technology Bomber program incepted in 1979. Competition between contractors vying to build this new aircraft was eventually narrowed to two team proposals: one Northrop and Boeing and the other from Lockheed and Rockwell. Both teams presented flying wing designs, but Northrop’s experience pushed it over the edge. The Northrop-Boeing design was selected on October 20, 1981.
By then, Jack Northrop was confined to a wheel chair and unable to speak. Nevertheless, when the Air Force briefed him on the new project, the B-2 Spirit bomber, he was deeply moved. Seeing the flying wing configuration that incorporated many of his own designs alongside a scale model, Northrop reportedly wrote a shaky note on a piece of paper that simply read, “Now I know why God has kept me alive for 25 years.” Northrop died ten months later, never having seen his flying wing realize its incredible potential.
The first B-2 rolled out in November 1988 and made its first flight on July 17, 1989. It began flying for the US Air Force in 1991, the same year the service, Boeing, and Northrop won the National Aeronautic Association’s Colliers Trophy for the design, development, production, and flight testing of the cutting edge aircraft. The NAA made note of the wing’s significant contribution to America’s enduring leadership in aerospace and noted it as a technology that would advanced national security. More than two decades later, the Air Force still has 20 B-2 Spirits in service, and it remains one of the most celebrated strategic bombers of all time.
Sources: Northrop Grumman; Century of Flight; “Clipped Wings: the Death of Jack Northrop’s Flying Wing Bombers” by Bud Baker; Boeing; “B-2: the Spirit of Innovation” by Rebecca Grant; US Air Force; National Aeronautics Association; globalsecurity.org on YB-49; globalsecurity.org on XB-35.
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