Paper plane

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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 paperbaord.

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.

Contents 1 Advanced paper gliders 1.1 Developments 1.2 Technological introductions 1.3 Material considerations 1.4 Directions in advanced paper aircraft design 1.5 Rubber-band powered paper models 1936–1947 1.6 White Wings 1.7 Paper Pilot 1.8 Paper helicopters (autogyros) 2 World records 3 Aerodynamics 3.1 General aerodynamics 3.1.1 Critical Re 3.1.2 Aerofoils 3.1.3 Origami Flying Wings 4 Space flight 5 See also 6 References 7 Notable books 8 External links

[edit] Advanced paper gliders

[edit] Developments

Paper gliders have experienced three forms of advanced development in the period 1930–1988:

• High performance
• Scale modeling
• Fewer extra folds

[edit] Technological introductions

Technology responsible for the advancement of paper aeroplane construction:

• Inexpensive CAD software for 2D part design
• Widespread manufacture, and inexpensive nature of acetal air-annealed glues, e.g. Bostick Clear-bond.
• Inexpensive Ink-jet, and Laser-jet computer printers, for accurate aircraft part reproduction
• The advent of the Internet, and widespread information sharing

[edit] Material considerations

Paper's density is higher than lighter materials such as balsa wood, and so in consequence a conventional origami paper glider (see above) 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.

[edit] Directions in advanced paper aircraft design

Accomplished engineers, and enthusiasts have found that using paper as a construction material allows, with care, for the replication of performance characteristics which can exceed those of conventional hand-launched free flight gliders, if use of engineering principles and aeronautics are included during the process of design. As a result, two distinct design sets (Ninomiya, 1969 and Mathews, 1982 : see below) have emerged, both possessing remarkable performance a full two orders of magnitude removed from conventional gliders.

As far as scale modelling goes, paper aircraft modelling has aided full scale as well as modellers. The first conceptions of scale model or semi-scale gliders appeared in the "Great International Paper Airplane Book", 1967.

Design of paper models is an attractive pursuit, as design of wings and other surfaces can be completely in-scale by tracing flight surfaces with precision. Further, CAD software can be used in plotting the shapes of wings, tailplanes and other components for easy reproduction of parts for assembly. With care, it is even possible to colour in a model airframe before construction commences, or print patterns upon it during the process of reproduction.

During the Second World War a peak was reached with flying card models, where rubber-powered fighters were produced. This peak has been reached many times since then for scale model paper aircraft. Care in construction can produce flying models which are superior in strength and lightness to balsa and foam models, so that micro radio-control and electric power may be employed in these airframes. Larger scale construction with corrugate cardboard, re-inforced with other materials is another option to radio-control models to be built, for modelers desiring inexpensive 'disposable' airframes.

[edit] Rubber-band powered paper models 1936–1947

Wallis Rigby demonstrated a model of Amy Johnson's Gipsy Moth G-AAAH to the Daily Mail newspaper, resulting in the distribution of over half a million copies of this small model through the aegis of that paper.

Rigby's models had sufficient performance thanks to an elegant construction method, where tiny tabs bent at right angles ensured that the models maintained mechanical strength without excessive recourse to adhesives. Completion required the use of a pair of scissors and a tube of trusty Seccotine glue. Tiny stones were recommended as nose ballast, which would be inserted during construction and sealed into place with sticky paper.

The contemporary youth comic publishing industry invited Rigby to design other models that could be placed within the pages of weekly comics, and the 'Comic Weekly' ran a series whereby the card parts of a small monoplane was included week by week (additional items needed were a pepperpot for the nose cone and a propeller fashioned from tinplate with bearings made from beads of a necklace), the models were powered with am motor. These models are reported to have had adequate performance.

Shredded Wheat and other cereal manufacturers commissioned subjects, some including a set of 36 models.

During World War Two, Rigby moved to the United States where he set up his New York office trading under the name of American Telasco, Ltd. A new series of U.S.Army and Navy airplanes were distributed across the country to servicemen. Press and radio coverage ensured excellent publicity for these projects. Contests were organised. Card and paper modelling experienced great interest during this period, due to the widespread ban on the use of strategic materials for use on models and other commercial goods. Over 50,000 copies of his lithographed books were produced during this period.

Rigby returned to the United Kingdom after WWII and once again kept up with the times, producing models of subjects of the day. Large liners, locomotives and jet powered boats and aeroplanes began to appear not only as cut out books but also in kit form.

One of his rarest kits is that of a Jetex model rocket-powered Javelin card model kit, as a result of the large number that burnt due to modellers failing to add silver foil inserts into the structure.

[edit] White Wings

In Japan in the late 1970s, Professor Yasuaki Ninomiya designed an advanced type of paper aircraft, which are sold as the 'White Wings' Series of paper glider packs.

White Wings are a stark departure from conventional paper aircraft, in that their fuselages and wings are paper templates cut and glued together. They were designed with the aid of low-speed aerodynamics. The early models were explicitly hand drawn, but by the 1980's these had their parts drafted with the use of CAD software.

Prof. Ninomiya's designs also included, for the first time in any paper model, working propellors driven by airflow, in particular for his profile scale models of the Cessna Skymaster and Piaggio P.136 of 1967. Noteworthy as well was the careful design of gliders so that they could fly without ballast – his F-4 Phantom II model is able to be flown immediately without recourse to paperclips etc.

The high performance gliders have fuselages that are kept rigid by the use of a balsa fuselage profile bonded to the paper components. The paper used is quite heavy, approximately twice the weight of standard drawing cartridge paper, but lighter than lightweight cardboard. Original White Wings were entirely paper, requiring patience and skill. Later however, balsa-wood fuselages were used, and White Wings were sold "pre-cut", making construction easier. The aerofoil used is a Gottingen 801 (curved plate), and a pattern is supplied as a cutout part of each kit.

[edit] Paper Pilot

Professor E.H. Mathews and the University of the Witwatersrand, in South Africa, developed a more mature form of the White Wings gliders for sale to South African children and teenagers in the 1980s. His gliders are designed using aerodynamic principles in the style of the White Wings series, they differ in construction, being of all-paper rather than paper-balsa laminate fuselage. The first book of gliders was entitled 'Paper Pilot', and was published by Struik in 1987. The Paper Pilot gliders are a watershed in paper model aircraft – they are the first commercial paper models to have been designed completely on a CAD system, and the first to be tested exhaustively in a wind tunnel.

The performance of the Paper Pilot gliders is almost equivalent to that of the Ninomiya gliders – but one of the first designs, a profile model of the SAAF C-160Z Transall, has a gliding distance of greater than the length of a rugby pitch.

The early gliders were designed to incorporate a catapult hook shaped from a paper clip. Later designs (and upgraded early designs) incorporated the addition of a bungee hook, permitting extremely long distance flights.

A remarkable characteristic of the Paper Pilot gliders are their ability to be flight trimmed – to the point of being able to fly straight in confined spaces, which few modern paper gliders can do.

E.H. Mathews designs then developed in 12 Planes for the Paper Pilot (Struik, 1994) into aircraft with three dimensional fuselages – models included the J-3 Piper Cub, Beech Stagger-Wing Biplane, Lockheed U-2 and Britten-Norman Trislander (a subject of a high performance flat glider earier in the series).

E.H. Mathews authored a commemorative model of the SAAF Junkers Ju-52/3m 'Johan van Riebeek' in 1999, and an as-yet unreleased model of the Airbus A-320 airliner in South African Airways colours, seen on the SABC youth TV program 'Tekkies' in 1998, as a prototype.

The most astonishing glider developed by Prof. Mathews was the Papercopter – a free-flight paper model helicopter, with a rotationally stabilised ring-wing as the flight dynamic element. Three variants were developed – the standard Papercopter of 1991, the Airwolf (1993) and the Stealth helicopter.

[edit] Paper helicopters (autogyros)

The world's first known published paper autogyro (engineless helicopter) by Richard K Neu appeared in "The Great International Paper Airplane Book" published in 1967. Its wings fly in a circle around a central ballast shaft as it descends vertically. This basic design has been published several times and is widely known.

The world's first known published forward gliding paper autogyro with forward pointing body lifted by spinning blades was built by James Zongker. It appears on page 53 of "The Paper Airplane Book: The Official Book of the Second Great International Paper Airplane Contest" published in 1985 by Science Magazine. Its twin contra-rotating blades automatically spin on paper axles upon launch to provide lift.

As noted above (see entry, Paper Pilot), E.H. Mathews developed a flight stable paper model helicopter. This has a ring wing, and flaps for adjusting for flight for stability, positioned on the inboard edge of the ring. While not an autogyro per sê, this paper model aircraft class falls within the general design of a paper model helicopter, and does possess a rotational flight element producing lift during forward flight. Papercopters, as Professor Mathews labeled them, are unique among paper model rotorcraft in having a range and velocity far in excess of all other classes, able to fly quite quickly, and with a range of between 10–15 m. The longest flight time is 27.6 seconds^{[citation needed]}.

[edit] World records

There are multiple goals for a flight:

• Distance (javelin throwing).
• Time (javelin throwing straight up with subsequent metamorphosis into a sailplane).
• Aerobatic (looping).
• Stable flight to understand flight mechanics of a good plane.

For every goal there is a typical plane and sometimes a world record.^[1]

There have been many attempts over the years to break the barriers of throwing a paper plane for the longest time aloft. Ken Blackburn held this Guinness World Record for 13 years (1983–1996) and had regained the record on October 1998 by keeping his paper plane aloft for 27.6 seconds (indoors). This was confirmed by Guinness officials and a CNN report.^[2] The paper plane that Blackburn used in this record breaking attempt was a "glider".

Takuo Toda, who is an engineer and president of the Japan origami aeroplane association^[3], set a new record for longest paper airplane flight at a competition in Hiroshima Prefecture in April 2009.^[4] His record flight topped Blackburn's by 0.3 seconds. He folded his plane, measuring approximately 10 cm in length, from a single sheet of paper, though his plane in this attempt included cellophane tape.^[3]

In December, 2009, Toda achieved a 26.1 second record for a plane (10 cm in length) made with nothing but one sheet of paper, no scissors or glue or tape. The record was set in a Japan Air Lines hangar at Tokyo's Haneda airport. Toda's goal is to break the 30-second mark.^[3]

[edit] Aerodynamics

[edit] General aerodynamics

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.

[edit] Critical Re

The Reynolds number range of the paper model aircraft is reasonably wide:

• 2,000–12,000 for Origami aircraft
• 4,000–16,900 for Compound Origami (involving adhesives and aerodynamic refinements)
• 9,000–39,000 for Profile Performance (White Wings, Paper Pilot, et al.)
• 19,200–56,000 for Scale Performance (White Wings, Paper Pilot, et al.)
• 22,000–93,000 for Scale Models (complex structures)

These ranges are indicative. As noted above the mass:density ratio of paper prevents performance from reaching those of Balsa models in terms of expressions of power to weight, but for models with wingspans of between 250 mm and 1,200 mm, the Critical Re is very similar to balsa model gliders of similar dimensions.

Paper models typically have a wing aspect ratio that is very high (model sailplanes) or very low (the classic paper dart), and therefore are in almost all cases flying at velocities far below their wing planform and aerofoil Critical Re, where flow would break down from laminar to turbulent.

Most origami paper darts tend to be flying within turbulent air in any case, and as such, are important to research into turbulent flow as are low-Re lifting surfaces found in nature such as leaves of trees and plants as well as the wings of insects.

High performance profile and scale models do approach their wing section's critical Re in flight, which is a noteworthy achievement in terms of paper model design. Performance is derived of the fact that wings of these gliders are in fact performing as well as it is possible for them to perform, given their material limitations.

Experiments in different material finishes in recent years have revealed some interesting relationships in Re and paper models. Performance of origami and compound origami structures improves markedly with the introduction of smooth paper, though this is also aided by the paper's higher mass and consequently better penetration.

More marginal performance and scale types generally do not benefit from heavier, shinier surfaces. Performance profile-fuselage types do experience somewhat improved performance if shiny, slippery paper is used in construction, but although there is a velocity improvement, this is offset very often by a poorer l/d ratio. Scale types have experience negative performance at the addition of heavy shiny papers in their construction.

[edit] Aerofoils

Wing profile sections in models vary, depending on type:

• Origami : Gottingen flat-plate, or Jedelsky-form for folded leading edges.
• Compound Origami : Identical with origami, though often with sealed edges – 45% improvement in Cd.
• Profile Performance: Gottingen curved-plate, with profile similar to Gottingen 801.
• Scale Performance: Gottingen 801 or any other wing aerofoil
• Scale Models: This varies on model type (see below)

Camber of profiles varies, too. In general, the lower the Re, the greater the camber. Origami types will have 'ludicrous' or very high cambers in comparison with more marginally performing scale types, whose escalating masses demand higher flying speeds and so lower induced drag from high camber, though this will vary depending on type being modelled.

In the case of scale performance and scale models, the modellers intent will define the type of aerofoil section chosen. WWI biplanes, if designed for flight performance, will often have curved-plate aerofoils, as these produce a highly cambered surfaces and Coefficient of Lift (Cl) for low gliding airspeeds. WWII monoplanes will often have very scale-like sections, though with increased trailing edge droop to improve camber in comparison with scale counterparts.

Similarly, size, airspeed and mass will have very big impacts on choice of aerofoil, though this is a universal consideration in model aeroplane design, no matter the material.

[edit] Origami Flying Wings

The former Guinness world record holder Tim Richardson disagrees with the decision to put a 'tail' on the paper plane. His explanation of paper plane aerodynamics on his website mentions that the tail is not needed. He uses the real-life B-2 Spirit flying wing bomber as an example, stating that the weights along the wing should be put forward in order to stabilize the plane. (Note: paper airplanes do not need a tail primarily because they typically have a large, thin fuselage, which acts to prevent yaw, and wings along the entire length, which prevents pitch.)

Independently, Edmond Hui invented a Stealth Bomber-like paper airplane called the Paperang in 1977,^[5] based on hang glider aerodynamics. Uniquely, it has properly controlled airfoil sections, high aspect ratio wings, and a construction method designed to allow the builder to vary every aspect of its shape. It was the subject of a book, Amazing Paper Airplanes in 1987, and a number of newspaper articles in 1992. It is ineligible for most paper airplane competitions due to the use of a staple, but it has extremely high gliding performance exceeding glide ratios of 12 to 1 with good stability.

In 1975, origami artist Michael LaFosse designed a pure origami (one sheet; no cutting, glue or staples...) flying wing, which he named the "Art Deco Wing".

Though its aerodynamic form mimics some hang glider and supersonic airfoils, its invention evolved from exploring the beauty of folded paper first. Its glide ratio and stability are on a par with many of the best paper wing constructions that use glue, tape or staples. This design was first published in 1984 in the book "Wings and Things", by Stephen Weiss, St. Martin's Press.

Although it is a common view that light paper planes go farther than heavy ones, this is considered to be untrue by Blackburn. Blackburn's record-breaking 20-year-old paper plane^[6] was based on his belief that the best planes had short wings and are "heavy" at the point of the launch phase in which the thrower throws the paper plane into the air, and at the same time longer wings and a "lighter" weight would allow the paper plane to have better flight times but this cannot be thrown hard with much pressure into the air as a "heavy" weighted launch phase. According to Blackburn, "For maximum height and for a good transition to gliding flight, the throw must be within 10 degrees of vertical" — which shows that a speed of at least 60 miles per hour (about 100 kilometers per hour) is the amount needed to throw the paper plane successfully.

After the folding there are still gaps between different layers of folded paper (tearoff edge). These and the kinks transversal to the airflow may have a detrimental effect on aerodynamics, especially on the upper side of the wing. In some models the surfaces are not aligned to the direction of flow acting as airbrakes (notice the airbrakes of the B-2 in the picture above!). Typically the center of mass is at 1/4 and the center of area is at 1/2 of the plane lengths. Two methods exist to shift the center of mass to the front. One rolls up the leading edge which then stays unswept. The other uses a swept wing or axial folding to produce something like a fuselage extending out of leading edge of the wing.

[edit] Space flight

There may one day be an origami airplane launched from space. A prototype passed a durability test in a wind tunnel in March 2008, and Japan's space agency JAXA considered a launch from the International Space Station. However, the plane developers, Taduo Toda (see World Records above) and fellow enthusiast Shinji Suzuki, an aeronautical engineer and professor at Tokyo University, postponed the attempt after acknowledging it would be all but impossible to track them during the planes' week-long journey to Earth, assuming any of them survived the searing descent. The developers continue, in 2009, with hopes that China or Russia will back further efforts on the project.^[3]

[edit] See also

• Klutz book of paper airplanes
• Model aircraft

[edit] References

[edit] Notable books

• The Great International Paper Airplane Book, by Jerry Mander, George Dippel and Howard Gossage; 1967,1988
• Whitewings: Excellent Paper Airplanes, by Dr. Yasuaki Ninomiya; AGCO Ltd., Osako, Japan, 1980.
• The Ultimate Paper Airplane, by Richard Kline; Fireside Book, New York, 1985.
• Paper Pilot, by E.H. Mathews, Struik, Johannesburg, 1987
• Paper Pilot 2, by E.H. Mathews, Struik, Johannesburg, 1990
• Paper Pilot 3, by E.H. Mathews, Struik, Johannesburg, 1992
• 12 Planes for the Paper Pilot, by E.H. Mathews, Struik, Johannesburg, 1995
• Paper Airplanes, by Richard Slade, 1972 (Scale Model Aircraft)
• The Know How Book of Paper Aeroplanes, Know How Series, Usborne Books, London, 1979
• The Gliding Flight, by John M. Collins, Ten Speed Press, 1989
• Fantastic Flight, by John M. Collins, Ten Speed Press, 2004

[edit] External links

• Paper Airplanes at the Open Directory Project
• The Open Paper Plane Database User-created Creative Commons paper airplane instructions.
• Paper Airplanes +50 models of exotics paper airplanes.
• OrigamiTube for easy instructional videos on folding planes.
• Greatest Paper AirplanesComputer Generated Videos on folding 50 paper airplanes.
• xplanes4u Learn to fold the Spirit of America and American Flyer paper airplanes.
• Paper Aeronautics Association A portal for paper planes with planes of all difficulties.