At the Singapore Airshow, the exhibition halls are lined with scale models, mock cockpits, and interactive displays showing the latest commercial jets and aviation technology. One booth is drawing particular attention: Comac, China's state-owned planemaker, which has made significant strides since its C919 passenger jet flew to Singapore in its first trip outside of Chinese territory two years ago. The plane is designed to compete with the Airbus A320neo and Boeing 737 MAX and is increasingly