GRADIENT'S BLISS
reviewed by Greg Hamerton
23 October 2001

Gradient was created in 1998 by the world-class Czech competition pilot Ondrej Dupal. Three years of producing good gliders and they're still going strong. All manufacture is done within the Czech republic, allowing Gradient complete control over their product.

Gradient's AvaxRS won the 2001 World Air Games and has a reputation for being a well-behaved glider with exceptional performance. The Bliss is their latest release, SHV certified in March, DHV 2/3 certified in April2001. It is intended for experienced pilots and ambitious cross-country flyers.

CONSTRUCTION : Simple rigging is used, with a continuous system of small U-bracing ribs (three cells at a time) supporting the attachment points along A, B, C and D spans. A second strip of reinforcing fabric spans the D's. Ondrej Dupal explains : 'If the leading edge is well-finished, it is under strong tension, so doesn't need extra reinforcement, but the trailing edge can be sensitive.'

The cell-widths narrow progressively towards the tips. Contrary to the popular trend of closed leading-edge cells, the Bliss takes development in another direction. For seven cells from the centre, the cell openings are 7.5cm, then they taper over three cells to become 3.5cm for another six, taper again over three to a short section of three cells with 1cm gauze-covered openings, and then remain closed for the last six cells. This gauze section allows the ears to deflate when pulling big-ears, but helps to slow the spillage of air when you pump against a collapse, ensuring a direct reaction.

The tapered, narrow leading-edge-opening looks clean and tight in the air. Although it is difficult to objectively test the benefit of such design, the Bliss does have a resilient feel in the air which suggests the leading edge is kept firm and well-tensioned across the span.

Porcher Marine's 'New Skytex' fabric gives the Saphir that lovely crinkly feel, and a small, light pack. The glider comes with a large, sturdy backpack with well-designed tightening straps that span the zips, an outer pouch, and wide, comfortable shoulder-and-waist straps. Unfortunately it hangs below the waist-level, which puts strain on your back during long walkouts.

LAUNCH : The Bliss fills immediately and comes overhead with ease, with no tendency to drop back, and an easy recovery if its dips down (just lean into your harness). It is easy to kite overhead, and the Bliss lifts off at low speed. Lovely.

HANDLING IN THE SKY : It feels similar to its predecessor the Saphir2000, although the Bliss is more refined, and more agile. The Bliss offers a measured turn, which is efficient and flatter than that of the Saphir, but it lacks the energy retention I am used to in a DHV2/3. Something like the Magic allows a 'whip' turn to be generated by holding the wing back, and then releasing the outside brake to swing the wing around. This is useful for tight, narrow cores - the Bliss prefers to turn on the inside brake first. It is also fairly stable with regards to weight-shift input. Don't get me wrong, it is an agile wing, the agility just becomes limited at a certain point.

There is a big advantage to this inherent stability. In everything but the smallest cores, the Bliss has a steady, smooth turn which is efficient and easy to maintain. In those 'bucking summer days' you won't have to worry about controlling the energy of the wing much. It's obviously been designed with a reassuring feel in mind, and what it lacks in 'energetic excitement' it makes up for in 'autopilot ease'. Let's face it - most pilots don't want an 'excitable' wing! I found myself really enjoying the 'ignorant bliss' on those days when other pilots were complaining about turbulence.

Brake pressure is moderate. Mild feedback comes equally through the brake lines (by way of a simple generalised tug) and through the risers. The handling becomes 'dull' on deep brake - the Bliss needs good speed to offer any sensitivity.

SAFETY : The Bliss has an average stall point, reached with brakes held at the seatboard level for some time. The tips bend back quickly into a classic horseshoe shape. It jumps far ahead to recover (even from mild deep stalls) and the dive should always be dampened with the brakes.

It is reasonably resistant to negative spins, but once begun, the spin generates fast rotations and should be avoided. Pilots who are used to tight-turning wings (Freex Spark, Airwave Magic) should be careful to give the Bliss time to complete the turn in narrow cores.

Wingovers take a while to build up, confirming the stable character of the wing. However, get the timing right and it does hook around wonderfully, much tighter than the Saphir.

I found that the Bliss rolls / oscillates a little in turbulence without active piloting. With a little bit of input it smoothens out.

I had a big front collapse in very rough conditions, but it inflated quickly on its own. A blow-out on full speed bar in horrible ridge-wash (yeah, I shouldn't have taken off!) also opened squarely. Induced front tucks showed slightly delayed openings, with a positive dive forward on recovery.

Asymmetric collapses are rare - in windy rough thermic conditions, I had none even though I was fiddling with a camera set-up for long periods of the flight (there's nothing like trying to rig a digi-cam on a pole on a spring day to test your nerves!) If the wing does collapse, it is remarkably easy to counter-steer. I spent some time with a 50% asymmetric held in above the launch site, trying to get down to photograph height. The wing showed no tendency to stall, even with the collapse held in and with deep counter-steering.

If you do not react to an asymmetric though, you'll find the Bliss in an accelerating sideslip, which generates a lot of speed at 90 degrees as it hooks around in a turn. This speed soon smacks the wing out at 180degrees, so it has a good and spontaneous recovery. You quickly become centred under the wing, and the spiral ends before it has really begun, but as with all wings with a 2/3 score on an asymmetric collapse, pilots need a certain minimum level of awareness when flying close to a ridge. I wouldn't consider the asymmetric 'hot', merely 'average'. Sometimes the wing banged out before turning 90degrees. On speedbar, the unchecked asymmetric loses height rapidly, and although it also smacks out spontaneously, it earns a 2/3 score during the DHV tests.

I emailed Ondrej the following question : 'Do you think the rapid loss of altitude due to the spiral turn can be blamed on the extremely narrow leading edge openings and narrow cells near the outer section of the wing? I thought maybe because the reinflation there was delayed along the nose, the glider was being pulled into more of a turn than would be the case with wider cell openings / quick tip reinflation.'

Ondrej disagreed. 'The reducing cell-openings was the result of quite intensive testing and I don't think that this is the main reason of DHV 2-3 for accelerated asymmetric tuck. The Bliss was made for ambitious and experienced pilots, so we adjusted the glider exactly for those pilots to give them the opportunity to use the glider in the full range of their capability for maneuvrability and performance. The really huge range of speed is the main reason for the DHV2-3.'

Pulling in the outer A line brings in an average section of the wing for 'Big ears'. Unfortunately there are no split-A's on the Bliss, a feature I missed when needing to slope-land in a hurry (yup, you guessed it, that was the horribly windy flight mentioned above ...) But by holding the lines in deeply you'll get a good sink rate and a solid glider, easy to weightshift turn, with no tendency to stall even under abuse. The ears do not reinflate on their own, and need a solid pump to clear.

PERFORMANCE : The 38km/h trim speed is good, a standard speed for the Serial class these days. On glide the Bliss is on a par with the Airwave Magic and Nova Argon, and a touch slower than the Apco Simba. Where it gains on the other wings around is that the Bliss is remarkably mellow and stable to fly.

On speedbar, there is a linear progression on the A/B/C group for 2/3rds of the 16cm travel. An interesting feature is the 'sliding' D-riser system (first used on Gradient's AvaxRX), which extends the back risers far more than the others. Ondrej Dupal explained that this produces more performance at higher speed without the problem of front stall or asymmetric tucks. 'It offers the Bliss a really big speed range while using quite a short travel on the speed bar.'

I enjoyed the solid smooth feel of the speedbar, and the reassuring stability - I could use the bar in turbulence without needing to back off at every bump. At full speed bar there is a little deformation of the leading edge (the cells hollow in front), but it does not affect the stability - I clocked it at an averaged 52km/h, held for a long time through an active sky.

SUMMARY : The Bliss is a mellow, reassuring, simple-to-fly glider which would appeal to cross-country pilots who like stability in greater proportion than sensitivity.

If there is a line between safety and excitement, Gradient have elected to walk on the conservative side of that line with the Bliss. I recommend it to the 'regular to advanced XC pilots and junior competition pilots', and for those experienced hands who just want to relax while crossing the Alps or blazing through the desert summer flatlands. Although Ondrej insists that 'DHV2-3 was our goal and Gradient doesn't want to offer such a high performance glider to DHV2 pilots', I feel that the Bliss is the one glider in the 2/3 class which I could recommend without reservation to someone who is ready to spread their wings into the top of the Performance class. It does not require any particular style of piloting or gifted awareness to tap into what it offers.

TECHNICAL SPECIFICATIONS : For more information visit Gradient on the web at http://www.gradient.cx
Thanks to the Gradient importer James Braid for the wing.
Contact him on + 27 (0)82 9565391 or email j.braid@ee.wits.ac.za

* Note : Multiply by the correction factor to scale the results to a standardised condition of 1000m altitude, 15 deg.C air and a pilot at the maximum certified weight limit (assumed roughly 3% increase in speed per 500m, 2% increase per 5 deg. C and 2% increase per 5kg extra weight). Humidity and turbulence could cause further variations from the standard. I use a fifteen-second average to provide 'highest sustainable speed'.