Nasa ParaWing

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NPW 9B plans
Nasa Para Wing (model 9B) is built from 6 panels attached together when following this layout
before all I want to precise some points :
- the layout has been provided to me by  Bill Painter (Arizona)
- the idea to add an extra "C line" is from Stelios Alex (Greece)
- my modest contribution is "limited" to this page , to the bridling, to the excel spreadsheet and to the exe !
Cutting layout of NPW9B is extremly cost effective as there are no scraps..
to design your kite use the Nasa Para Wing bridling calculator. 
Software features :

choose kite dimension
compute profiles
choose brake and main lines
choose number of lines
choose bridling mode (regular or cascade)
import/export of profiles
render the NPW9b in VRML


If you prefer Excel spreadsheets, here you will find what you are looking for.
exemple here after is directly extracted from excel spreadsheet which allows to compute all dimensions of the kite..
beware that the excel sheet is less accurate than the exe. You SHOULDN'T use it to build the kite but better use the exe.

download excel spreadsheet

type "A" length ( "Calculations" page, cell C9)

all other dimensions will follow.

Cutting layout is extremly simple :

Measures are provided without margins or seam allowances..
  • To build the kite, jump to page "sail detail" from NPW5. Technics are absolutly identical
  • For bridling, it's the same, nothing has changed  for A and B lines (excepted bridles lengths)
  • A11 and A12 are connected to brake line, but B lines are only connected to the main flying lines
  • THE big change is (thanks Stelios !) when we add the third bridling line on the wing :
    • 6 bridling points are regularly dispatched on the bottom of the middle line of the wing
    • first point (C6) is located on the trailing edge, then just go up to C1.
    • distance between two C points : 
    • C5 and C6 are connected to a brake line. Other points are on the main lines
    • finaly, NPW9b exits with two models :
    • standard (or narrow) model. The "B" width of the center panel is B = A/2, there are 4 darts (K) as for NPW5
    • wide model. The "B" width of the center panel is B = 2A/3, there are 5 darts (K).
    • The exe is self adaptative to sail model (wide or narrow). Wide sails are more stable and powerful. Narrow sails are faster but less stable and less powerful. The default profile of the exe is a wide one.
Question : Does NPW9b fly ?

Answer : YES it does fly VERY well !!!

You  will find a "readme" file attached to the bridling calculator package toghether with several profiles (flying ones) of NPW9b.
the 3 following profiles belong to the "NPW9b Pionniers", launch the exe, import the profiles and compare them :

  • NEW : Fredrik has efficiently improved the NPW nose by adding an extra bridle 
    • This new 'Vnose' results in less distorsion of the nose and permits the use of a more wing-like profile.
    • How to do the 'Vnose' :
      • suppress the T on each side of the nose (but keep the others)
      • add an extra bridle going from the nose tip to the first dart (on the wing edge, where the dart is folded)
      • this extra bride should have the lenght T*3.3 (could be changed as it is an empirical value)
      • Tie bridle A1 (shortened in the provided "Vnose profile" by T*1.5) to this extra line with a bridle knot. This knot should be able to slide on the extra line so that A1 can find its optimal position by itself
      • here is the tuned profile with this "Vnose" Buzzard_Vnose_031022_NPW9B.txt Beware that this profile could seem a bit weird as my exe DOESN'T take the extra bridle into account (for the moment :-). To see the actual profile of the Buzzard Vnose on the calculator, type in value 162.50 at box A1 with A=138 cm. This value represents an approximation of the "effective sum" of the bridle A1 and the extra bridle  Here is the full readme file provided by Fredrik on his Vnose : Buzzard Vnose readme.txt 

THANKS to all of you !!!

Here is the Buzzard during its first test flights, it was in dark winter in Sweden !

And here is the Vnose profile flying on the Mali's NPW9b of Fredrik