What is a Delta Kite?
Welcome to Volume 3 of our series: Starting With The Basics!
In honor of Francis Rogallo's 114th birthday this upcoming week, we thought it would be fitting to discuss Delta Kites! While the "delta" shape existed before him, Rogallo is the reason the delta became the dominant force in high performance and stunt kite flying.
Francis Rogallo (pictured above).
So, What Exactly is a Delta Kite?
A Delta kite is a triangular shaped kite, known for stable flight in low wind. It is a great choice for beginners because of its stability, capability to fly in light winds and a simple set up and launch! They come in a variety of sizes, for all different skill levels. Here's a few reasons why they're so popular:
- Beginner friendly!
- Fly in a wide range of wind (5-20mph)
- Portable and easy to fold up to transport
- Variety of colors and sizes
9ft Delta Kite in Northern Lights (pictured above).
What is the Difference Between Delta and Diamond Kites?
The biggest differences between delta and diamond kites are shape, and performance. While both are beginner friendly and good choices to start out with, they do have some key differences that you may want to consider when choosing between the two. Lets break it down:
Delta Kites
Shape: Triangular
Set Up: Very easy to launch, stable in air
Wind: Flies well in low wind
Best For: Beginners looking for a stable kite and consistent flying
Diamond Kites
Shape: Diamond
Set Up: Easy set up, but harder to launch
Wind: Best for 5-15mph winds and needs a tail for stability
Best For: Younger kids, and for a traditional flying experience
Both are excellent choices, although deltas are typically more forgiving and reliable for a fun filled and stable flight!
Best Flyers
Swift Delta (pictured above).
Who Invented the Delta Kite?
The delta kite as we know it today is the result of several decades of innovation and competing designs. Its origins date back to the 1940s. The first delta prototype was developed in the 1940s by Wilbur "Bill" Green, who was a Texas architect and the founder of Fantastic Kites (which later became Gayla Kites in 1961). He was granted a patent in 1957 for a kite design featuring a keel.
This distinction is crucial when comparing his work to Francis Rogallo. While Rogallo’s famous flexible wing patent was granted earlier, in 1951, his design lacked both a keel and wing spars.
The transition from experimental designs to the modern recreational kite happened in the 1960s:
1963: Al Hartig designed the "Red Baron," a cloth version of a modified red Gayla kite.
1967: Hartig obtained a patent for this specific configuration.
Hartig’s refined design became the definitive blueprint for the contemporary Delta kite, balancing the stability of Green's keel with the aerodynamic lessons of the era!
Francis Rogallo’s Legacy
While Bill Green gave the Delta its stability through the keel, Francis Rogallo is responsible for the aerodynamic principles that define modern flexible flight. In 1948, working alongside his wife Gertrude, Rogallo developed the first functional flexible-wing prototype using Gertrude’s kitchen curtains and a window fan for a wind tunnel. Their design was revolutionary because it was the first airfoil that didn't require rigid members to maintain its shape. Instead, it used wind pressure to inflate and create lift.
In an article written in Ford Times magazine in the March 1951 edition, Rogallo said:
"We did our kite research on Saturdays and Sundays when the weather permitted, and on those days trips to the flying grounds were frequent. Our efforts were not in vain, for after many attempts we succeeded in making one of our kites fly. After that taste of success, weekends were not enough. In order to pursue our experiments at night we installed a thirty-six inch fan in our home so that we could test kites in the doorway between two rooms. Many shapes and materials were tested in our wind tunnel and in flight until we had developed a thoroughly satisfactory model."
Gertrude and Francis Rogallo (pictured above).
Francis and Son, Bobby (pictured above).
Photographs by Lawrence S. Williams, via Ford Times Magazine. March 1951.
Expanding the Horizon of the Rogallo Wing
In 1951, the Rogallo's received a patent for their design. They developed and began selling a toy kite called the flexi-kite. The Rogallo wing paved the way for modern hang gliders, paragliders, and stunt kites!
Francis Rogallo testing flying his Flexi-kite, PC.5274, Francis Rogallo Papers, Outer Banks History Center (pictured above).
In the early 1960s, Australian John Dickenson constructed a water-skiing kite inspired by a magazine photo of the Rogallo wing. This pivotal adaptation birthed the modern hang glider, sparking a massive surge in the sport's popularity! Rogallo’s vision was realized: he had provided a simple, affordable gateway for the everyday person to take to the skies.
In 1987, Francis Rogallo was inducted into the North Carolina Sports Hall of Fame, recognizing his transformative impact on hang gliding. Beyond the sporting world, his aerospace genius was honored by both NASA and the Smithsonian National Air and Space Museum. Today, he is remembered not just as an engineer, but as the man who gave wings to the common person.
Celebration
Each year, Kitty Hawk Kites staff members and hang gliding school completes the same number of flights as Francis Rogallo's number of birthdays. This year, the lucky number is 114! You can join us Saturday January 31st around 9am at Jockey’s Ridge State Park in Nags Head, NC for the annual tradition!
Francis Rogallo flying the flexi-wing (pictured above).