JET FLAP Technology ® (JFT). Air is conducted from the bottom sail (pressure area) to the top sail (low-pressure area) and is blown out with higher speed. The connection is established through jet shaped channels, which are located in the rear section of the wing. The additional escaping air mass on the upper sail decelerates the air current displacement, stall occurs later and more When increasing the angle-of-attack, the danger of airflow stall will be minimized. The result of the delayed stall is a higher power/m². Furthermore, the JET FLAPs decrease luffing, The effectiveness of the JET FLAP Technology has been proved during flight tests and numerous studies.
I'm not sure how this fits into the discussion, but I think it's also worth mentioning that the OSP (a BASE canopy) also has holes which allow air to bleed through the center of the wing. The purpose there is also stability, especially at low airspeeds.
Ironically enough, I'm told the Squirrel's new slider down prototypes utilize the same technology, or at least similar.
Charlie - I'm pretty sure the hole in the V4 & V5 is intended to make the legwing violently oscillate at high speed and during steep dives. It was reportedly a design mole, planted in Robi's head many years ago by Matt & Mike to induce us to defect to their products. It worked.
For something which "doesn t work" just take a look at the last races like WWL, RBTG and PR and you ll see that Vampire are closely following Jedei/ Apache with a much smaller size. And take a look at the N4S video and let me know where you can see as sharp and quick turn in other brand video. But if it don t work for you, just find something easier to handle...
(This post was edited by alygator on Aug 16, 2014, 7:37 AM)
The "hole in the leg wing/deflector" functions the same way as the leading edge slot on the airplane wing. It provides smoother, cleaner airflow over leg wing in order to generate additional lift. Additional benefit is, as Jarno mentioned, cleaner and stronger airflow for pilot chute extraction and increased lateral stability. The result is very agile suit. Downside is that suits equipped with this slot are not that suitable for back flying.