The D4 has a massive +12cm/s sink rate advantage over the D3 during full speed glides. In calm air, this results in a full glider-cone height gain every minute. In turbulence, the gain is larger as the D4 cuts through turbulence using gusts for altitude gain, much like a competition wing. The max speed of the D4 is 3kph faster, walking away from the D3 in accelerated flight.
Intuitive and efficient AoA control, an improved airfoil design, and an optimised internal structure make the D4 an XC glide machine in turbulence. Its structure is the strongest we have yet made. Even in aggressive turbulence the profile remains undisturbed, retaining its shape and efficiency without performance loss from chordwise deformation.
New ACR System
The new Ozone Active Control Risers, inherited from the Mantra series, allows full AoA control throughout the speed range without deforming the camber of the profile. The ACR system acts on B & C lines giving 2-liner control with the comfort of a 3-liner design.
This is the best behaved Delta yet. The D4 is highly resistant to collapse, even at full speed in turbulence. The post-collapse behaviour is the mildest of the entire Delta series. This has been achieved by keeping the aspect ratio relatively low, by improving the structure and line architecture, and by optimising wing twist. Extensive testing shows little tendency to shoot or rotate after side collapse, and no shock re-inflation. The behaviour in frontals is excellent with immediate reopening.
Thanks to the Ozone Shark Nose profile, the wing is resistant to spin & stall and can be flown safely at low speed making top landings, or landings in tight spots, simple for a wing of this class.
Tuned for Joy
Compared to the D3, the handling is vastly improved. The brakes are linear — precise in the first part of the range and effective in the second. It is easy to adjust the angle of bank and to place the wing exactly where you want in the core. Strong chord structure and high sail cohesion make for highly coordinated roll/yaw and an agile, exciting feel.
The Delta 4 is for intermediate to advanced pilots who fly 70-100 hours per year and have SIV experience. Due to its ease of use and high levels of passive safety, it is also very suitable for pilots moving up from the category below. More experienced pilots who want to fly with higher margins of safety will find the D4 a satisfying XC tool with class-leading performance.