【运输】旋翼飞机：一种在飞行中兼有飞机和航空器特点的飞机

aircrafts using in flight the features of both aeroplane and

landing aid for aircrafts

balancing hinged surfaces for aircrafts

tracking system for guns on aircrafts

altitude control in aircrafts

self-propelled vessel for launching, towing aircrafts

ground installation for aircrafts

structures, floating for aircrafts