YUKON, Okla. - NASA engineer and champion aerobatic pilot Marta Bohn-Meyer was killed Sunday when her plane crashed during practice for next week's National Aerobatic Championships. The crash occurred shortly before noon near Oklahoma City, where she was piloting her home-built Giles G-300 airplane. She had been joined there by her husband and fellow aerobatic pilot, Bob Meyer. "Flying and doing things with airplanes is my passion," she once said. "Given a choice, I'll go fly airplanes." According to the International Aerobatic Club, Bohn-Meyer had pulled into a vertical maneuver when the cockpit canopy came off. The airplane then crashed...