Rogallo wing facts for kids
The Rogallo wing is a special type of flexible wing. In 1948, Francis Rogallo, an engineer from NASA, and his wife Gertrude Rogallo invented this wing. They called it the Parawing, but it's also known as the "Rogallo Wing" or flexible wing. NASA thought about using Rogallo's flexible wing to help space capsules land safely, like for the Mercury and Gemini missions. However, by 1964, they decided to use regular parachutes instead for Gemini.
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How the Rogallo Wing Was Invented
Francis Rogallo became interested in flexible wings around 1945. He and his wife loved building and flying kites as a hobby. They couldn't get official help or money for their wing idea, even from Rogallo's employer, the National Advisory Committee for Aeronautics (NACA). So, they worked on their experiments in their own time.
By the end of 1948, they had two working designs for a flexible wing. One was a kite they called "Flexi-Kite," and the other was a gliding parachute they later named a "paraglider." Rogallo and his wife received a patent for their flexible square wing in March 1951. Selling the Flexi-Kite as a toy helped them pay for their research and made their design well-known.
NASA's Research with the Rogallo Wing
In the late 1950s and early 1960s, American aerospace companies were busy designing parachutes to bring space capsules back to Earth. For a short time, NASA thought about using the Rogallo wing instead of the usual round parachutes for the Project Mercury capsule, because they were having some problems with the traditional designs.
Later, the Rogallo wing was the first choice for the Project Gemini capsule. But again, they ran into development issues, and in the end, they had to switch back to using regular parachutes.
How Rogallo Wings Are Built
Today, when people say "Rogallo wing," they usually mean a wing made of two parts that look like the surface of a cone, with both cones pointing forward.
- Slow Rogallo wings have wide, shallow cones.
- Faster Rogallo wings (for high speeds below the speed of sound or even above it) have long, narrow cones.
The Rogallo wing is a simple and cheap type of flying wing with amazing features. The wing itself isn't a kite, a glider, or a powered aircraft until it's attached or set up to glide or be powered. This means what kind of aircraft it becomes depends on how it's used.
You can often see the Rogallo wing in toy kites. But it has also been used to make parachutes for spacecraft, sport parachutes, very light powered aircraft like the trike, and hang gliders.
The wing is designed to bend and flex in the wind. This flexibility makes the wing less affected by bumpy air (turbulence) and gives a smoother flight than a stiff-winged aircraft of the same size. The back edge of the wing, which isn't stiff, allows the wing to twist. This helps the wing stay stable in the air without needing a tail.
Rogallo Wing Hang Gliders
Between 1961 and 1962, an airplane engineer named Barry Hill Palmer launched several versions of a framed Rogallo wing hang glider by foot. He wanted to keep the fun and sport of hang gliding going. Another person important to the Rogallo wing hang glider's story was James Hobson. His "Rogallo Hang Glider" was featured in a magazine in 1962 and even shown on TV.
Later, in Australia in mid-1963, John W. Dickenson decided to build a controllable kite/glider for waterskiing. He said he got the idea from a flexible-wing aircraft made by Ryan Aeronautical. The news about the Paresev hang gliders tested by NASA and other space companies made many inventors interested in the Rogallo wing design. This led to a new wave of interest in hang gliding in the 1960s.
John Dickenson's design used a single point to hang the pilot and an A-frame control bar. The pilot would sit on a seat and use their body weight to control the glider by pushing and pulling the A-frame. This flexible wing, called the "Ski Wing," was first flown in public in September 1963. Rod Fuller flew it while being towed by a motorboat.
Today, most Rogallo wings are controlled by shifting the pilot's weight. The pilot hangs from one or more points below the wing and moves their body left, right, forward, or backward. This changes the wing's pitch and roll (how it tilts up/down and side-to-side). NASA studied several ways to control Rogallo wings from 1958 through the 1960s.
Rogallo Skydiving Canopies
After NASA stopped its Paresev research in 1965, the idea of gliding parachutes was used for military and other purposes on Earth. This led to versions of the flexible Rogallo wing being used in the sport of skydiving.
Irvin, a company, sold Hawk and Eagle models in 1967, but only for a short time. Then, in 1968, they introduced the Irvin Delta II Parawing. This was the most produced and improved early Rogallo wing for skydiving. It was made in factories in the U.S., Canada, and the U.K.
The Delta II had colored lines to help skydivers pack it correctly. It also had a special strap called an "Opening Shock Inhibitor" (OSI) that helped reduce the strong jolt when the parachute opened. It was a bit bigger to pack than other parachutes of the time. As one of the first gliding parachutes, many skydivers were interested in it.
However, it became known for sometimes having problems when opening, possibly because packing it was different from other parachutes. But when it opened correctly, it could glide and perform much better than other parachutes like the Para-Commander.
The Delta II was available until 1975 and opened the door for other Rogallo Wing skydiving parachutes. One example was the Handbury Para-Dactyl, made in the mid to late 1970s. This parachute used a "sail-slider" to make openings smoother, just like modern parachutes do. A Russian Rogallo-Wing parachute called a PZ-81 was still available as late as 1995. By the late 1970s, newer "ram-air" parachutes became more popular because they were more reliable, performed better, and took up less space when packed.
Rogallo Kites
Rogallo wing kites control how they fly up and down (pitch) using a bridle. A bridle is a set of strings that helps set the wing's angle of attack (how much it tilts into the wind). Usually, a string loop goes from the front to the end of the kite's center pole. The person flying the kite ties knots in the bridle to set the angle. Kites made in large numbers often use a plastic film triangle for the bridle, which is sealed to the center pole.
Steerable Rogallo kites usually have two bridles that set a fixed pitch. They use two strings, one on each side of the kite, to change how it rolls (tilts side to side).
Rogallo also created soft foil designs in the 1960s. These have been changed for "traction kiting," which is using a kite to pull something, like a person on a board. These designs have two keels (center lines) and cone-shaped wings with many attachment points. They can be used with two or four control lines. They pull very well but don't have as wide a "wind window" (area where they can fly) as newer designs.
Early Rogallo Patents
Even though similar designs existed before and important improvements like the triangular control frame were made by others, Rogallo holds several patents for his inventions.
- Rogallo, Gertrude et al., "Flexible Kite", US patent 2,546,078, Filed November 23, 1948
- Rogallo, Gertrude et al., "Flexible Kite", US patent 2,751,172, Filed November 17, 1952
Images for kids
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Gemini Rogallo wing during tests at Edwards Air Force Base in August 1964.
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Rogallo wing considered as a candidate recovery system for the Apollo spacecraft
See also
- Flight Dynamics Flightsail
- Hang gliding
- History of hang gliding
- Paragliding
- Wing
