Is a rivalry brewing? Both companies claim to have evaluated and rejected their competitor's approach during initial planning. "We are the only one aiming at validating the concept of a cost-effective high-speed helicopter," says Jean-Michel Billig, the vice president of R&D at Eurocopter. The names of the prototypes certainly suggest a spirit of one-upmanship. Although Billig calls the choice of X3 "coincidence," Chris Van Buiten, the director of Sikorsky Innovations, says jokingly, "We'll name our next one the X-Bajillion to make sure we win the grade-school naming contest."