Oxford and Cambridge have now decided to remove the words CAN'T and IMPOSSIBLE from their dictionary    Jessica Cox, 25, a girl born without arms, stands inside an aircraft. The girl from Tucson , Arizona got the Sport Pilot certificate lately and became the first pilot licensed to fly using only her feet.   Jessica Cox of Tucson was born without arms, but that has only stopped her from doing one thing: using the word "can't." Her latest flight into the seemingly impossible is becoming the first pilot licensed to fly using only her feet. With one foot manning the controls and the other delicately guiding the steering column, Cox, 25, soared to achieve a Sport Pilot certificate. Her certificate qualifies her to fly a light-sport aircraft to altitudes of 10,000 feet.. "She's a good pilot. She's rock solid," said Parrish Traweek, 42, the flying instructor at San Manuel's Ray Blair Airport . Parrish Traweek runs PC Aircraft Maintenance and Flight Services and has trained many pilots, some of whom didn't come close to Cox's abilities. "When she came up here driving a car," Traweek recalled, "I knew she'd have no problem flying a plane." Doctors never learned why she was born without arms, but she figured out early on that she didn't want to use prosthetic devices.