A paper plane, paper airplane, paper glider, or paper dart is a toy plane made out of paper. It is also sometimes called aerogami, after origami (the Japanese art of paper folding). In Japanese, it is called kamihikōki. It is popular because it is one of the easiest types of origami for a novice to master. The most basic paper plane would only take five steps to complete. The term "paper plane" can also be referred to those made from cardboard.
Da Vinci is often cited as the inventor of paper planes, although this is debatable since the Chinese invented both paper and the kite. However, he did make reference to building a model plane out of parchment. Arguably the father of model fliers was George Cayley.
The earliest known date of the creation of modern paper planes was said to have been in 1909. However, the most accepted version of the creation was two decades later in 1930 by Jack Northrop (co-founder of Lockheed Corporation). Northrop had used paper planes as tests of ideas for flying real-life aircraft.
There have been many improvements in the designs for velocity, lift, style and fashion over subsequent years.
Paper's density is higher than lighter materials such as balsa wood, and so in consequence a conventional origami paper glider has considerably lower performance due to higher drag and imperfect aerodynamic section of its wings. Conventional balsa gliders will always outperform conventional paper aircraft for this reason.
However, unlike balsa gliders, paper gliders have a far higher strength/thickness ratio – a sheet of office-quality 80 g/sq m photocopier/laser printer paper, for example, has approximate in-scale strength of aircraft-grade aluminium sheet metal. Card stock has the approximate properties of steel at the scale of paper model aircraft.
Paper aircraft are a class of model aeroplane, and so do not experience aerodynamic forces differently from other types of flying model. However, their construction material produces a number dissimilar effects on flight performance in comparison with aircraft built from different materials.
The Klutz Book of Paper Airplanes (2004) is a well-known book describing in detail how to make ten different types of paper airplanes. The book also gives instruction on how to test and tweak flights, and provides games to play with the paper airplanes.
Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License and Creative Commons Attribution-ShareAlike License.)