Predicting the Pass...
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Predicting the Passive Safety Of Beginner PPG Wings

mystery man
New Pilot Registered

Check out this analysis I wrote to evaluate the passive safety of beginner PPG wings from the specs:


There has to be a way to judge the passive stability of a wing and its agility other than listening to sales pitches and watching endless videos, and I believe there is.  A mathematical review of manufacturer’s specifications can lead to some conclusions, without viewing flight tests.  A wing’s stability in turbulence, its ability to recover from collapses, and its agility are largely a function of its projected aspect ratio and degree of arch.  Projected aspect ratio is the projected span (in flight) divided by its projected chord.  Wings with smaller projected aspect ratios are more stable but less agile. Wings with larger projected aspect ratios (narrow wings) are less stable. Wings with larger arches are less affected by turbulence.  They dampen turbulence. Arches that are more flat are more affected by turbulence.  Arch is the projected span (in flight) divided by its flat span (on the ground).

Reviewing the data below, the Mojo PWR 2 would be the most stable (greatest passive safety in turbulence and quickest to recover from a collapse, and the least agile).  The data suggests the Gin Pegasus 3 and the Kona 2 are real charmers for beginners, because their projected aspect ratios are just a little higher than the Mojo, meaning they are predicted to have good stability in turbulence, and to be more agile than the Mojo.  Going down the list, stability decreases.  The Cima PWR is predicted to be much more agile but less stable in turbulence because of its higher projected aspect ratio and because the wing is more flat in flight. I personally believe a beginner wing should have an aspect ratio of no more than 3.7, and an arch of no greater than 80%, but that’s my opinion.  I call this the “3.7 rule.”

NOTE:  This analysis is my own creation.  It is not to be considered expert advice from a PPG wing designer. It is a mathematical analysis, based on my experience designing RC aircraft, and my educational minor in Mathematics. Consider it my opinion. Obviously, there are other factors to weigh such as wing loading, wing profile, ease of inflation, etc., that a beginner should consider. I suggest only a starting point or framework as a basis for comparing beginner ppg wings. Author:  Mike S


                   Projected Aspect Ratio        Rating         Arch     WT. Range (kg)      Area (m2)

  1. Mojo PWR 2          3.46                      EN-A/DGAC             77.5%       95-150                   28.3
  2. Gin Pegasus 3       3.6                        EN-A/DGAC             80%         85-140                   28.4
  3. Kona 2                 3.62                       EN-B/DGAC               76%          90-145                   27.3
  4. Roadster 3/Spyder 3.7                        EN-B                           -             80-140                   26.0
  5. Sky Flexor             3.7                        DGAC                         81%         90-130                  27.0
  6. Cima PWR             3.82                      DGAC                        85.3%       80-140                  25.0
  7. Dudek Universal1.1  3.83                  EN-B/LTFB                80.0 %      90-140                  28.0


This topic was modified 1 month ago 8 times by Mike S
Topic starter Posted : December 3, 2021 6:21 pm
mystery man
New Pilot Registered

The BGD Magic with an aspect ratio of 3.5 also looks like a good prospect for a beginner. 

Here's another wing that looks like a winner for beginners:  Dudek Nemo 4, PAR 3.65, Arch 78.4%, agile and EN-A rated.

This post was modified 2 weeks ago by Mike S
This post was modified 5 days ago by Mike S
Topic starter Posted : January 3, 2022 7:56 pm
60f8307a9c2a0 bpthumb
Member Moderator

Thanks for the info @Mike S.  I have only ever flown my Roadster 3.  It would be interesting as I progress to get some time on a few other wings to see how the whole agility thing changes with design (and or loading/size).

Posted : January 7, 2022 1:36 pm