Nasa Para Wing

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NPW5 in flight

Originally developed by Francis Rogallo as a parachute for NASA's Apollo program , the Nasa Para Wing (NPW) was designed as a stunt kite . A total of 24 test models (NPW1 - NPW24) were designed through ongoing modifications to the basic concept. The fifth model in particular promised the greatest possible flight stability - the first thing to do was to redesign the NPW5 as a steerable wing.

In contrast to many other stunt kites , the NPWs consist of only one layer of fabric that forms a cap on the nose. Only through this and the bridle lines does the wing get a wing-like profile. The pressure of the wind keeps the sail filled without the need for additional bracing or stiffening.

Originally popular as a two-line kite, it is now mainly flown as a four-line kite. Since the lines of the trailing edge are led separately to the handles, most of the flight maneuvers typical of a four-line line are possible with the NPW 5. However, the wind window in this model is quite limited due to the design, so that the NPW5 can be used as a towing kite for z. B. Buggies can only be used to a limited extent.

Soon there was an improved version, the eNPW5 from Peter de Jong (Netherlands), alongside the commercially sold NPW5. The American kite maker Bill Painter modified the model of the NPW5 in 2002 together with the Frenchman Jean-Pierre Gleyzes by connecting a further middle section with another wing panel. As a result, several companies also sold the NPW9, so that Painter and Gleyzes renamed their (non-commercial) concept to NPW9b. The NPW9b is more stable, has a much larger wind window, develops stronger pull and is simpler and easier to control.

Further improvements emerged from the NPW9b concept, which are also not sold commercially. In 2003 Fredrik Lejonklou modified the center section of the NPW9b and developed his own profile for the wing - he published the plans under the name Teega . In 2004, Jan Claes from Belgium widened the middle section of the NPW9b three times and at the same time modified the nose of the profile. The result is the NPW-HA . The problem of the collapsing wing, which still occurred quite often on the NPW5 and eNPW5, can largely be remedied on all other models mentioned by fine-tuning the bridle lines.

The construction of all NPWs allows a considerable sail area with little use of material. The NPW5 shown here is 195 cm wide and works to capacity from wind force 4. Larger sails, especially those of the NPW9b, are also used as towing kites for kite buggy riding . The advantages of these sail concepts are their small pack size, but also their extremely low price. At the same time, almost anyone can make such a kite: All seams are straight and flat (in contrast to parafoils, for example ). The very low weight makes these kites real light wind wonders. A breath of wind is enough and the wing remains stable. In addition, the construction is almost indestructible: In contrast to more complicated wing designs, no cells can burst or tear even in the event of a collision with hard ground. A disadvantage compared to other towing kites is the smaller wind window; However, this could be improved by far in the further development of NPW5 to the successor models. The low airspeed, which made the NPW5 unpopular with many pilots, could be increased noticeably with the further development of the concept.

Further developments of the concept

There are many possible goals for improving the concept. Jan Claes and the Dane Bill Rassmussen are currently working on the development of a static single-line kite based on the NPW.

Another focus of development is to develop a sail that does not need bridles. These brake the sail in the air, which reduces the light wind properties and the wind window. However, the construction of such a sail turns out to be very complex, as the cut already defines the three-dimensional shape that is created by the bridle lines in the classic Nasa Para Wing.

Approaches to designing hybrid NASA Para Wings are detached from the conventional concept. Here parts of the sail are constructed as an air chamber, which would possibly improve the stability of the canopy at the leading edge when it is folded.

The American company KiteShip proves that kite sails, which consist of only one layer of fabric, have great development potential. B. tankers or container ships with large single-ply kite sails can pull. This technology reduces the fuel consumption of the conventional drive.

Build your own plans

The models NPW9b, Teega, NPW-HA and NPWC are not offered by any manufacturer and may only be used privately. There are plans on the Internet for all the models mentioned here, e.g. T. as computer programs have been published. These allow you to choose any keel height, on the basis of which all other parameters are calculated.

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