Predicting the Passive Safety Of Beginner PPG Wings
Check out this analysis I wrote to evaluate the passive safety of beginner PPG wings from the specs:
PREDICTION OF STABILITY AND AGILITY OF BEGINNER PPG WINGS
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
BEGINNER PPG WINGS
Projected Aspect Ratio Rating Arch WT. Range (kg) Area (m2)
- Mojo PWR 2 3.46 EN-A/DGAC 77.5% 95-150 28.3
- Gin Pegasus 3 3.6 EN-A/DGAC 80% 85-140 28.4
- Kona 2 3.62 EN-B/DGAC 76% 90-145 27.3
- Roadster 3/Spyder 3.7 EN-B - 80-140 26.0
- Sky Flexor 3.7 DGAC 81% 90-130 27.0
- Cima PWR 3.82 DGAC 85.3% 80-140 25.0
- Dudek Universal1.1 3.83 EN-B/LTFB 80.0 % 90-140 28.0
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).