Leonardo da Vinci sketched a glider, an aircraft concept with fixed wings and a pilot suspended beneath them.
Unlike a flapping ornithopter, a glider does not propel itself by repeatedly moving its wings. It depends on aerodynamic lift and loses height unless rising air supplies additional energy. Leonardo’s studies of bird flight led him to consider both powered and unpowered ways of remaining airborne.
His glider-related drawings include wing structures influenced by bats and birds. The designs were exploratory rather than a single standardized aircraft, and no surviving evidence shows that Leonardo built and flew one. Some modern reconstructions have tested interpretations of his sketches, but their results do not prove that the original machine was practical.
The term glider describes the operating principle, not necessarily Leonardo’s exact historical label. It is therefore more precise than calling every one of his flying sketches an airplane or helicopter.