1966

Parafoil

Domina Jalbert (1904–1991)

When we think of engineering, our minds often turn to hard objects: bridges, airplanes, transmissions. But it is also possible for an engineered object to be soft and flexible. The modern sport parachute is a good example—there is engineering throughout. Think about the traditional round parachute. It is a piece of fabric sewn together from a set of panels. Thin ropes attach to the edge and tie the parachute to a pair of shoulder straps. A backpack and harness attach the parachute to the skydiver’s body. The skydiver basically floats straight down under the canopy, at the mercy of the wind.

The modern parafoil, first patented by Domina Jalbert in 1966, is a complete reconceptualization that has several big advantages over a round parachute. The parafoil is essentially a fabric wing with an airfoil shape. Ram air at the front of the airfoil inflates the wing and keeps it semi-rigid. Since it is an airfoil, it flies—it has forward speed and a glide ratio. The lines that attach the parafoil to the skydiver keep it aligned overhead. The back lines attach to loops that the skydiver holds in his or her hands to control the parachute. Pulling on the left toggle causes the left side of the parafoil to slow down. Ditto on the right side. Pulling down both toggles causes the parachute to slow down and flare, which is especially useful for landing.

The advantage of the parafoil is the fact that it is flying. The skydiver can steer the parachute and have much more control over the landing. Parachuting is much safer as a result. Engineers can control a number of variables when designing the parafoil: the shape, the thickness of the airfoil, the overall size, the aspect ratio, the number of cells, the fabric, etc. Some parafoils are small and thin for speed flying. Some are large for leisurely parasailing. The design depends on the goals and needs of the user.

Engineers might not have anticipated the tricks and stunts that experienced skydivers can do with parafoils. Engineers create the technology, and then enthusiasts take it to the limit.

SEE ALSO Plastic (1856), Kinsol Trestle Bridge (1920), Human-Powered Airplane (1977).

Pictured: Domina Jalbert’s 1966 patent for the parafoil.