Swing Sphera RS: in the sphere of tranquility

Better than the Sphere's little sister, the Libra RS. The differences are seemingly small, but in flight they are critical. The handles on the rear rows are slightly larger and much more comfortable, and the rear rows themselves don't twist, allowing full handle operation. Otherwise, it's still the same modern Swing — no miracles, but not without a spark of creativity and unusualness. Narrow, neatly stitched strap, supplemented in places by a thick and very slippery Dyneema line. Branded brake handles with rigid inserts, which I personally do not like, but which can be easily removed. Kinematics without over-complication, bearing blocks are used in the most stressed areas. The acceleration system is equipped with an overdrive bead, which allows you to choose between a long speed system travel and a heavy load on your legs.

Everything is high quality and thorough, which is what you would expect from a German company. The lines on all tiers are not braided, but with high quality anti-UV impregnation, which is not always the case. The lines scheme is simple and clear: A2A'1B3. Under the canopy there is also nothing out of the ordinary...

...but some non-trivial things happen to the canopy. Or rather, inside the canopy. Yes, yes, the Sphera RS - as the name implies - has the Swing RAST inside, i.e. a full span partition across the chord. The purpose of the baffle is to impede the flow between the front and back of the chord, which Swing claims has many positive effects, such as increased resistance to collapses. There are also less positive effects, but more on that below. The wing stiffeners are interesting. They are made of nitinol, but in the front part of the chord the nitinol is covered with plastic. This is mainly to prevent the nitinol from rubbing against the fabric, but of course the plastic also affects the stiffness of the wing and its mass. And the weight of the Sphere is not insignificant — about 6 kg! Roughly two times the weight of Niviuk's weightless Klimbers. But there's a reason for this mass. The most portable elements of the Sphere are made of Skytex with a density of 38 g/m2, and where the requirements for the fabric are softer, Skytex with a density of 31 and even 28 g/m2 is used. The rigid elements cover about 80% of the chord, so it is necessary to pack the Sphere very carefully and wrap the accordion around the harness. Wing shape is, surprisingly, the same shape that Swings had 10-15 years ago, instantly recognizable. AR is standard for EN D, about 7. Sections are neither too many nor too few — there's 75 of them. The quality of the cut and stitching is unquestionable, everything is neatly done.

The Sphera definitely behaves like a heavy wing! It comes over your head steadily and slowly, with almost no tendency to surge forward. Very nice in moderate and strong winds, less nice in no wind or back wind. The Cobra launch is possible with at least 4-5 m/s wind. Due to RAST, the trailing edge of the chord inflates slowly and difficult, and trailing edge flutter is possible.

Unfortunately, I did not have a chance to fly side-by-side with other EN D gliders, but my guess is that the Sphera's overall performance is good for the EN D class.

Speed measurements with the TAS probe gave +13...+15 km/h at 50% of the speed bar, +20...+22 km/h at full speed. Not the top of the EN D class, but quite good and acceptable. In addition, due to the Sphera's comfort and stability, you can use the speed system a lot even in a rough staff.

Normal, even, perhaps, better than average. I didn't notice any special "floatability" - but even without it Sphera confidently holds a small rate of descent in weak and medium thermals.

The brake response is not too sharp, but rather smooth, just what you need to work with any kind of thermal. When loaded below the middle of the certified weight range, the Sphera requires a lot of brake input to turn well, and the typical brake load is high in this case. After a few hours in the air, your arms may get tired. It's much better near the top of the certified weight range. The Sphera becomes more reactive, you need less brake input and less effort. I really liked the turning ability in this case. And regardless of the load, the Sphera is very responsive to weight changes! Better than typical for EN D wings.

The rear risers are Niviuk style: moderately loaded at trim speed, they become very light but still efficient when accelerating. At full speed you can control the Sphera with your fingertips on the rear handles. I personally like this!

The quietest and most peaceful EN D 2-liner I have ever flown! Sphera is incredibly pitch stable. Trying to create some pitch movement with "dolphins", I got no more than 20 degrees of pitch. Applying more brake results in almost nothing, the Sphera stands calmly above the pilot's head. The real pitches in moderately turbulent conditions are of similar amplitude, rarely reaching 30 degrees. The Sphera is also quite stable in yaw. Centering the thermals is easy and comfortable, with minimal parasitic movements. As for snakes and wobbles, they do exist, but it's really difficult to get them. Despite the AR of 7, the wing behaves like a monoblock! Quite a rare feeling in the EN D class. Load changes on brakes and main lines are smooth and gradual, the wing doesn't "slap" its pilot. Perfect!

Feedback. The Sigma 10 feeling! This Sphera "speaks" a very nice "language", discreet but explicit and easy to understand. But there's also a lot of "2-liner magic". Far from the lift, the Sphera tends to drift towards the core, giving clear and direct signals to the pilot. Closer to the core, it even tries to "auto-center"! Yes, this glider will not be thrown out of the core, it will try to jump in! The feedback from load changes on the brakes and harness is well present, well dosed, classic.

Calm power. That's how you can characterize the Sphera when it comes to dynamics and power capacity. Not too much, not too little — exactly what you expect from an EN D 2-liner!