What type of parachute did Leonardo da Vinci describe as a pyramid-shaped linen structure?

Leonardo da Vinci described a pyramidal parachute made from linen and supported by a wooden frame.

The proposal appears in the Codex Atlanticus and is generally dated to about 1485. Leonardo wrote that a person could throw themselves from a height while protected by a structure about 12 braccia wide and 12 braccia deep. The exact modern conversion of a braccio varies, but the dimensions indicate a substantial canopy.

The design’s pyramid shape was unlike the circular or ram-air parachutes used today. Its broad surface would create drag, and the rigid frame would keep the canopy open. Leonardo supplied a geometric description, yet there is no evidence that he performed a human test.

The design is a distinct invention from Leonardo’s aerial screw. The aerial screw sought upward lift through rotation, while the pyramidal parachute sought a controlled downward descent. That contrast shows Leonardo considering both major problems of early flight: staying in the air and surviving a fall.