A Timeless History
Leonardo drew flying machines for some twenty years and, as far as anyone knows, built none. His earliest sheet, c. 1478–80, is a single wing on a crank; by 1487–90 (Manuscript B, Paris) he had a whole craft, its pilot working the wings with hands and feet. Four centuries on, Otto Lilienthal made close to 2,000 glides on bird-shaped wings, 1891–96, and proved a person could fly — by gliding, not flapping.
SourceMuseo Galileo, leonardo//thek@, Codex Atlanticus ff. 858r, 824v, 1006v — teche.museogalileo.it · Smithsonian National Air and Space Museum, "Leonardo da Vinci and Flight" and "Lilienthal Glider" A19060001000 — airandspace.si.edu
Science In Action
Lift: a wing turns the air it meets downward, and the air pushes the wing up — Newton's third law at work • A bird's wing is an arm: the same bones, shoulder to fingertip, but far bigger flight muscles for its size • Flapping: the downstroke gives lift and thrust at once — what Leonardo tried to copy with cranks and cables • Power to weight: a person makes little power for the weight to lift; Snowbird needed 32 m of wing for 42 kg
SourceNASA Glenn Research Center, Beginner's Guide to Aeronautics, "What is Lift?" — grc.nasa.gov · É.-J. Marey, Le vol des oiseaux (Paris, 1890) · University of Toronto, "World record human-powered flight confirmed" — utoronto.ca
Arts
Leonardo studied bodies in motion before he drew machines to move. A Bear Walking, a silverpoint of about 1482–85 in the Metropolitan Museum, follows the animal mid-step, with a separate study of its paw; the same eye later filled the Codex on the Flight of Birds (1505–06) with wings turning in the wind. For him a paw, a wing and a lever obeyed one set of rules, and drawing was how he found them.
SourceThe Metropolitan Museum of Art, Robert Lehman Collection, 1975.1.369 — metmuseum.org · Smithsonian National Air and Space Museum, "Leonardo da Vinci and Flight" — airandspace.si.edu
Applications Today
Flapping never became the way we fly, but Leonardo's other lesson did: build light and learn from birds. In 1979 the pedal-driven Gossamer Albatross, 31.8 kg empty, crossed the English Channel in 2 h 49 min. In 2001 its makers' solar wing Helios, 75 m across and arched like a soaring bird, climbed to 29,524 m, a record for level flight by a winged aircraft. Engineers call this borrowing biomimicry.
SourceSmithsonian National Air and Space Museum, "MacCready Gossamer Albatross" A19810428000 — airandspace.si.edu · NASA Dryden Flight Research Center, fact sheet FS-068, "Helios Prototype" — nasa.gov
One more thingOn 2 August 2010 the Snowbird, a human-powered ornithopter, flapped for 19.3 seconds and 145 metres over Ontario — the first ever to sustain flight.
SourceUniversity of Toronto Institute for Aerospace Studies (UTIAS), pilot Todd Reichert; record confirmed by the Fédération Aéronautique Internationale, 2012 — utoronto.ca
As far as anyone knows, Leonardo built none of his flying machines. The model in Vinci, built after Manuscript B, was made in 1938.
[Otto Lilienthal gliding experiment] — Lilienthal in flight from his artificial hill (Fliegeberg, Lichterfelde near Berlin) — unidentified photographer — [1895?] — Library of Congress, Prints and Photographs Division, LOT 8127; digital file from the original photograph, 2688 × 2204 TIFF, cropped inside the mount to 4:3 — LC-DIG-ppmsca-02546 / LC-USZ62-19650
