The Italian polymath

Leonardo da Vinci Leonardo di ser Piero da Vinci (15 April 14522 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, Drawing, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially res ...

drew his design for an "aerial screw" in the late 1480s, while he was employed as a military engineer by Ludovico Sforza, Duke of Milan from 1494 to 1499. The original drawing is part of a manuscript dated to 1487 to 1490 and appears on folio 83-verso of , part of the papers removed from the

Biblioteca Ambrosiana The Biblioteca Ambrosiana is a historic library in Milan, Italy, also housing the Pinacoteca Ambrosiana, the Ambrosian art gallery. Named after Ambrose, the patron saint of Milan, it was founded in 1609 by Cardinal Federico Borromeo, whose agen ...

in 1795 by

Napoleon Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader who ...

and still held by the

Institut de France The (; ) is a French learned society, grouping five , including the Académie Française. It was established in 1795 at the direction of the National Convention. Located on the Quai de Conti in the 6th arrondissement of Paris, the institute ...

in Paris. Da Vinci biographer

Walter Isaacson Walter Seff Isaacson (born May 20, 1952) is an American author, journalist, and professor. He has been the President and CEO of the Aspen Institute, a nonpartisan policy studies organization based in Washington, D.C., the chair and CEO of CNN, ...

has expressed the belief that it was “devised for a theatrical spectacle”. The "aerial screw" was one of several aerial machines drawn by Leonardo, including an early parachute, an

ornithopter An ornithopter (from Greek ''ornis, ornith-'' "bird" and ''pteron'' "wing") is an aircraft that flies by flapping its wings. Designers sought to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, ...

and a

hang glider Hang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised foot-launched heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame cover ...

. The pen-and-ink sketch outlines an idea for a flying machine similar to a modern

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

, with a spiral rotor or "aerial screw" based on a

water screw A screw pump is a positive-displacement pump that use one or several screws to move fluid solids or liquids along the screw(s) axis. Three principal forms exist; In its simplest form (the Archimedes' screw pump or 'water screw'), a single scr ...

, but intended to push against the fluid of the air instead of water. The design comprises a large structure, built on a solid circular platform, with a central vertical pole supported by three diagonal members meeting at a small circular plate about half way up the pole. The upper half of the pole is the supportive axis for a large spiralling sail of linen with a radius of about , stiffened with starch. The inner edge of the sail winds clockwise around the pole, while the outer edge of the sail is connected by ropes or wires to a ring that rotates around the lower platform. The design envisions a crew of several people on the wooden platform running around the central pole while holding handles that rotate the sail. Leonardo's annotations suggest that a linen aerial screw, if turned quickly enough, would push against the air and lift the structure into the air. The notes indicate that Leonardo built small flying models of the aerial screw, but there were no indications for any provision to stop the reaction against the rotation of the sail from making the craft itself rotate in the opposite direction. It is conceivable that Leonardo could have constructed small working models, but a full-size working version could not have been realised for want of sufficiently light but strong materials, and a powerful enough drive for the screw. The bamboo helicopter, a toy flying machine based on similar principles, had been known in China since about 300 BC. The modern helicopter owes more to the bamboo helicopter than to Leonardo's aerial screw. In 2022 a drone based on Leonardo's design flew. Macchina volante - Museo scienza tecnologia Milano 09392 01.jpg, Model in the

Museo Nazionale Scienza e Tecnologia Leonardo da Vinci Museo Nazionale Scienza e Tecnologia Leonardo da Vinci in Milan, dedicated to painter and scientist Leonardo da Vinci, is the largest science and technology museum in Italy. It was opened on 5 February 1953 and inaugurated by Prime Minister Alci ...

, Milan DaVinci Helix Hubschraubermuseum Bueckeburg.jpg, Model in the

Hubschraubermuseum Bückeburg The Hubschraubermuseum Bückeburg (Bückeburg Helicopter Museum) is located in the German town of Bückeburg, 30 miles (50 km) to the west of Hanover. The museum is the sole museum in Germany specialising in rotary-wing flight and one of few ...

References

Folio83-verso, Manuscrit B
Institut de France

Leonardo3 Museum
Leonardo da Vinci's helicopter: 15th-century flight of fancy led to modern aeronautics
''The Conversation'', 3 May 2019
Leonardo da Vinci's Aerial Screw
COVE, 22 May 2019 {{Leonardo da Vinci Helicopters Leonardo da Vinci