How It Came to Be Edwards, Part II
Last Updated: Wednesday, 12 August 2015 04:31 Nick Spark Hits: 4443
A tremendous visionary, aviation engineer Jack Northrop's designs consistently pushed the envelope. In the late 1920's, he built an aircraft for Avion Co. that had a pusher engine and a radically diminutive tail structure -- so minimal that observers called the plane a "flying wing". Problems with the design kept it from production and led to the dissolution of Avion, but Northrop didn't give up. In 1939, he set up a new company, Northrop Aircraft, to build a more advanced design, the N-1.
In 1942 Northrop built the N-9M, a 60-foot tailless "flying wing" equipped with two propeller-driven, air-cooled pusher engines. It served as proof of concept for a gigantic, 172-foot wide bomber designated XB-35. "It was a beautiful concept," remembers Bob Cardenas, who first learned of the plane around 1946. "In a regular airplane you have a wing. You attach a fuselage. A fuselage is where you're carrying all the weight. So the wing's spar, that's holding that fuselage, has to be a very large, and very heavy structure. When you remove the fuselage and the tail, the total wing surface is all lift. You can go anywhere in the world in that airplane."
What a different 20 years makes! Above photo: The Northrop-designed Avion in flight, with pusher propeller, circa 1929. Photo below: The gigantic YB-49 takes off from the Northrop plant, circa 1948.
The range of the XB-35 intrigued military planners, who imagined that a prolonged war with Germany or Japan might require extreme long-range bombers. At one point in 1943, over 200 of the planes were on order; but problems encountered during the N-9M test program, including a fatal accident, eventually led to cancellation of the contract. Nevertheless an experimental program continued, and an XB-35 eventually flew in June of '46. By then, the Air Force had been persuaded to extend a contract for a jet-powered version of the plane, the YB-49. For Bob Cardenas, being assigned as chief test pilot on the YB-49 program initially seemed like a dream come true. The airplane itself represented a terrific leap forward in aviation technology. "As a test pilot of so-called 'X planes'," Cardenas remembers, "I probably flew about a dozen -- not on their first flights mind you. The one that of course caused me the most grief was the YB-49. I started first with the little N-9M propeller job. I learned that it had some different characteristics. In a normal airplane, you shove the right rudder, and you turn to the right. In a flying wing, you shove in the right rudder. and you're turning about the tip. So you have to coordinate the ailerons, elevons, with your rudder to get the proper turn. When you catch on, it's not much different."
What did give Cardenas pause, and what made him begin to believe the YB-49 might be an aircraft ahead of its time, was the plane's instability. "One of the first things you have to do (in a flight test program)," he explains, "is find out at what speeds it stalls. When an airplane stalls normally, the wing ceases giving you lift, and it falls off. You get a little turbulence. I knew (in the YB-49) I wouldn't get too much, cause the airplane had no tail. So, I was waiting for the slight buffet. But instead of that it gave a lurch and it went over backwards. And it started tumbling backwards." As the huge plane flipped end over end, Cardenas and his co-pilot Danny Forbes had their hands pinned to the ceiling by tremendous G-forces. The plane was completely out of control, and headed for the ground.
Fortunately for the test pilots, the YB-49 wasn't an ordinary airplane. For one thing, there were throttles located above the pilot, near the cockpit ceiling. "Although my rear end was off the seat," Cardenas recalls, "I was able to reach the left throttle and apply 100 percent power for engines on the left side." That did the trick: once the airplane had power on the left side, the airplane cartwheeled into a recoverable spin.
"When I landed from that flight," Bob Cardenas remembers, "I wrote a one page report: the aircraft is never to be intentionally stalled."