Too Much, Too Soon
A great entry in Air & Space Magazine’s ‘Memorable Flights’ series, this about test-flying the YB-49 Flying Wing. Here’s a bit about the stall tests:
I leveled the YB-49 at 20,000 feet, pulled back on the throttles, and waited for it to stop flying. Because most of the shudder you get in a stall comes from the tail, not the wing, I knew I wouldn’t get a big shudder. Sure enough, when the tailless airplane quit flying, instead of the normal shudder just before the nose drops, I experienced a violent pitch forward into a negative-G tumble, which pulled my rear end out of the seat. In a microsecond, I realized that I had no aerodynamic flow over any control surface that would allow me to recover. It was as if you took a nice, crisp, clean dollar bill out and let it go; it would go spinning around its center. The engineers later called it a lateral roll and said I had encountered inertial coupling.
Fortunately, the throttles were mounted up above my head, not down on the console where they normally are. There were two handles, one for the four left engines and one for the four right, just an arm’s length away. I was able to grab the left throttle and apply full power, which caused the aircraft to cartwheel. I was thrown into an inverted spin—one thing I knew how to get out of. I recovered at about 800 feet. After I landed, I wrote a brief report: “This aircraft is never to be intentionally stalled.” Later that night, I went to Pancho’s Happy Bottom Riding Club for a drink.
There’s more about test pilot Robert L. Cardenas’ reasoning that such a plane would need computers to keep up with the ever-changing dynamics of the aircraft, President Truman’s inspection of the plane, and an ill-advised flight at treetrop level down Pennsylvania Avenue.