An
ornithopter (from
Greek ornithos "bird" and
pteron "wing") is an
aircraft that
flies by flapping its
wings. Designers seek to imitate the flapping-wing flight of birds,
bats, and
insects. Though machines may differ in form, they are usually built on the same
scale as these flying creatures. Manned ornithopters have also been built, and some have been successful. The machines are of two general types: those with engines, and those powered by the
muscles of the
pilot.