Flying disc
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"Frisbee" redirects here. For the sport, see Ultimate (sport). For the amusement ride, see Frisbee (ride). For the type of UFO, see Flying saucer.

A flying disc is a disc-shaped glider that is generally plastic and roughly 20 to 25 cm (7.9 to 9.8 in) in diameter, with a lip. The shape of the disc, an airfoil in cross-section, allows it to fly by generating lift as it moves through the air while rotating.

The term frisbee, often used uncapitalized to generically describe all flying discs, has been a registered trademark of the Wham-O toy company. Though such use is not encouraged by the company, the common use of the name as a generic term has put the trademark in jeopardy.

Flying discs are thrown and caught for free-form recreation and as part of many different flying disc games. A wide range of flying disc variants are available commercially. Disc golf discs are usually smaller but denser and are tailored for particular flight profiles to increase/decrease stability and distance. Disc dog sports use relatively slow flying discs made of more pliable material to better resist a dog's bite and prevent injury to the dog.

Flying rings are also available, which typically fly significantly farther than any traditional flying disc. There are illuminated discs meant for night time play that use phosphorescent plastic, or battery powered light emitting diodes. There are also discs that whistle when they reach a certain velocity in flight.

History
The clay target used in trap shooting, almost identical to a flying disc in shape, was designed in the 19th century.
Walter Frederick Morrison discovered a market for the modern day flying disc in 1938 when he and his future wife Lucile were offered 25ยข for a cake pan that they were tossing back and forth to each other on the beach in Santa Monica, California. "That got the wheels turning, because you could buy a cake pan for 5 cents, and if people on the beach were willing to pay a quarter for it, well, there was a business", Morrison told The Virginian-Pilot in 2007.[cite this quote] They continued their business until World War II, when he served in the army Air Forces flying P-47s and spent time as a prisoner of war. Upon his return from the war, Morrison sketched a design for an aerodynamically-improved flying disc he dubbed the Whirlo-Way. By 1948 after design modifications and experimentation with several prototypes, Morrison and his business partner Warren Franscioni began producing the first plastic discs. They re-named their invention Flyin-Saucer in the wake of reported UFO sightings. "We worked fairs, demonstrating it", Morrison told the Virginian-Pilot. "That's where we learned we could sell these things, because people ate them up." Morrison and Franscioni ended their partnership in 1950. After further design refinements in 1955, Morrison began producing a new disc, which he called the Pluto Platter. He sold the rights to Wham-O on January 23, 1957 (his 37th birthday), and the following year, Morrison was awarded U.S. Design Patent D183,626 for his flying disc.

In June 1957, Wham-O co-founder Richard Knerr decided to stimulate sales by giving the discs the additional brand name "Frisbee" (pronounced "FRIZ'-bee") after learning that Connecticut college students were calling the Pluto Platter by that name, the term "Frisbee" coming from the name of the Bridgeport, CT pie manufacturer Frisbie Pie Company. "I thought the name was a horror...terrible", Morrison told The Press-Enterprise of Riverside[cite this quote] in 2007. In 1982 Morrison told Forbes magazine[cite this quote] he had received about $2 million in royalty payments and said "I wouldn't change the name of it for the world".

The man who was behind the Frisbee's phenomenal success however was "Steady" Ed Headrick, hired in 1964 as Wham-O's new General Manager and Vice President in charge of marketing. Headrick soon redesigned the Pluto Platter by reworking the rim thickness and top design, creating a more controllable disc that could be thrown accurately.

Sales soared for the toy, which was marketed as a new sport. In 1964, the first "Professional Model" went on sale. Headrick patented the new design as the Frisbee patent, highlighting the "Rings of Headrick" and marketed and pushed the Professional Model Frisbee and "Frisbee" as a sport. (U.S. Patent 3,359,678).

Headrick, commonly known as the "Father of Disc Sports", later founded "The International Frisbee Association (IFA)" and began establishing standards for various sports using the Frisbee such as Distance, Freestyle and Guts. Upon his death Headrick was cremated and, in accordance with his final requests, his ashes were molded into memorial Frisbees and given to family and close friends.[12]

Flying disc games
Main article: Flying disc games
Crosbee
Disc dog
Disc golf
Dodge disc
Double disc court
Durango boot
Flutterguts
Freestyle
Fricket (a.k.a. disc cricket, cups, Suzy sticks, crispy wickets)
Friskee
Goaltimate
Guts
Hot box
Kan-jam
Polish horseshoes
Schtick
Ultimate
In-or-Out box
In 2000 Walter Frederick Morrison publicly announced that he was not the inventor of the flying disc.

Physics
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Main article: Physics of flying discs

Flying disc freestyle
Lift is generated in primarily the same way as a traditional asymmetric airfoil, that is, by accelerating upper airflow such that a pressure difference gives rise to a lifting force. Small ridges near the leading edge act as turbulators, reducing flow separation by forcing the airflow to become turbulent after it passes over the ridges.

The rotating flying disc has a vertical angular momentum vector, stabilizing its attitude gyroscopically. Depending on the cross-sectional shape of the airfoil the amount of lift generated by the front and back parts of the disc may be unequal. If the disc were not spinning this would tend to make it pitch. When the disc is spinning, however, such a torque would cause it to precess about the roll axis, causing its trajectory to curve to the left or the right. Most discs are designed to be aerodynamically stable so that this roll is self-correcting for a fairly broad range of velocities and rates of spin. Many disc golf discs, however, are intentionally designed to be unstable. Higher rates of spin lead to better stability and, for a given rate of spin, there is generally a range of velocities that are stable.

Even a slight deformation in a disc (called a "Taco," which in extreme cases looks like a taco shell) can cause adverse affects when throwing long range. It can be observed by holding the disc horizontally at eye level and looking at the rim while slowly rotating the disc.