The BA 609 Tiltrotor is making its flying debut here at Le Bourget. Bell/Agusta Aerospace has brought the second prototype to Paris after it made its first public appearance late last month at an Italian air show. Potential European customers have recently expressed concern about the aircraft’s cost of ownership. Its U.S.-Italian manufacturer might thus hope to convince them about its unique capabilities by showcasing it here. The aircraft on display has been undergoing tests near Milan since November. Although it shares the same concept, the civil BA 609 is different from–and much smaller than–the military Bell Boeing V-22 Osprey. The company says the backlog is now more than 70 BA 609s.