Flight Test - Windtech Kali
by Ian Grayland
This review really began last summer whilst checking out a Windtech Tempest for a local pilot. The wind was fairly light so I popped the wing halfway up to fill it and slew it around, then dropped it back a couple of feet above the ground to check it, intending to pull it up again on the As. To my astonishment the Tempest slowly and smoothly rose all the way overhead against just the load on my carabiners. I made a mental note to look out for a new Windtech DHV1-2 wing, which I felt certain would be using the same aerofoil section. So, on to spring and the Kali…
The review wing is a Medium, certified DHV1-2. My winter weight (ahem) put me just under halfway up the the 90 - 110kg weight range with all the usual stuff in the harness for day one of testing. It was an unsoarable start with our longest hike to take-off, so my first job was to get all my kit in the rucksack. This is a single-zip type with an elasticated top periphery, fold-over lid and top compartment. Two compression straps are fitted each side and there are plenty of handles to pick it up from any angle. I had no difficulty fitting my rather awkward 'plank' harness, inverted, and all my gear into the main compartment, with my helmet neatly held on top by the peripheral elastic. A few seconds tweaking the adjustments had the load sitting high and comfortable with no shoulder strap load. I even enjoyed the hike.
Construction and materials
The wing is built from 50 cells with full-chord ribs throughout. The top surface is Skytex 9092 45g/m2 and the lower surface is lighter 40g/m2 9017, both in the new E85A finish. Ribs are 40g/m2 9017, E29A hard finish. Cells are arranged in blocks of five, with two internal 'V' tab braced cells each side of a centre cell. This carries its load via a neat, short, extra cascade in the middle of each group of three upper lines on each main.
Lines are Edelrid Kevlar-core throughout. The only addition to the three main lines - on four risers each side - is a single stabilo line with a tiny top cascade to two attachments at the tip. The result is a nicely minimised line-set in relation to the number of cells.
The mean line length is a good half-metre longer than most other wings of this class. As well as increasing roll stability, this gives a greater projected span for the wing size leading to an improved glide and minimum sink rate.
The four 19mm polyester risers are neat, tidy and pleasant to handle, with no nasty edges to snag and damage lines. Even the magnetic brake retainers are fitted with rubberised snagproof covers - nice. However, I would like to see the risers themselves better colour coded for quick identification. Control line pulleys are compact, smooth and free-running. The split A big ear riser is easy to get hold of and long enough to be useful, as is the floating 2:1 geared C riser. However, with full span Ds so easy to grab you will probably not choose to use the Cs to kill the wing on landing. The short B riser is a little more fiddly to get hold of for B stalls.
With 180mm of travel the speed system is unusual for DHV1-2 wing, incorporating spanwise differential by attaching the split A riser to the B gearing. This reduces the risk tip blow-outs when flying on the bar.
On the ground
I laid out the wing in a carefully chosen spot. Turbulent air, a very flat slope and a barbed-wire fence to clear on the edge of the hill - perfect.
Waiting for the wind to pick up would give me plenty of time for ground handling. I pulled up on the inner As to start, then all the As, then just the ears, then just leaning back and pulling nothing. Oh, and forgetting to hold the brake handles and pulling one B by mistake. End result? Same every time; wing smack overhead, steady as a rock and ready to launch. Forward launches were exactly the same. The Kali would rise clean and easy using every technique I tried, including no technique at all. Overpulling the inner As with malice would induce a mild centre tuck which popped out immediately with no horseshoe or failure to launch.
On the first take-off my immediate impression was of good glide performance.
Despite the very light wind the Kali slid off the hill and over the fence easily without any brake applied. The long lines gave a slightly remote feeling at first, especially when scratching low and fast in the light, gusty air. However this soon passed. I made a few landings to tweak the brake lengths, finally settling on shortening them by 60mm from the delivered length to suit my very low hang-points and shortish arms. With this setting I still can't quite stall, even with my thumbs pushing down the brake handle rings, but this feels just about right for verticaldescent top landings in tight areas with no danger of a stall or spin. In windier top landings I found I could kill the wing with C or D risers, either of which would keep the Kali firmly on the ground with no reinflation surges.
Brake forces are pleasantly light for a 1-2 and, despite the long travel mandated by the DHV, the Kali is not tiring to fly for long periods. Turn entry is most easily accomplished by a smooth application of one brake. The harder and faster you pull, the faster it goes into the turn. The Kali is very unfussy about weight-shift inputs; any of the current standard harnesses (Gin, Sup'Air, etc) should work well. Turns are best tightened by simply pulling more inside brake rather than leaning into it. Stop pulling and the wing quickly straightens up into level flight. In nice air I found I could go into gentle thermalling turns with a little outside weight shift and a squeeze of inside brake, resulting in a steady, flat circle with very good climb rate. Re-centring in this mode was best accomplished by simply easing up, or increasing the brake input.
Weight-shift control is sufficiently effective to allow S-turns on descents with the ears in, with or without speed bar applied. The ears are easy to hold in and the wing stays solid and reassuringly calm overhead throughout.
Flying against a variety of other wings quickly confirmed my feeling of the Kali's excellent glide performance. (It’s one of the best things about flying on the South Downs - a lot of good pilots, some on good gliders, all packed in to a very small space.) Considering my light wing loading, I was somewhat surprised to be catching up with most other wings when flying at the same height, and also surprised by my relative performance in stronger winds.
Trim speed is a comfortable 37km/h. Half bar takes this to around 46km/h with a very flat glide for a glider of this class. I was unable to get full speed with my normal setup, so I temporarily modified the Kali's 3:1 speed system to 2:1. The end result was an impressive 52km/h (at 99kg all-up).
It is always hard to put a precise number on best glide angle, even with big mountains and still air. Our small hills and ever-present wind make it impossible. In terms of penetration however, I am fairly sure that the Kali is more than a match for both the Mamboo and Sport 3 at the same size and loading at trim speed. On the bar it is noticeably faster than either.
The minimum sink rate is very good, once again easily matching the best of the competition, though flying very slowly to eke the most out of it can leave you awkwardly slow at times in thermic air.
On the descent, big ears give an increased sink rate of around 400fpm with a 2km/h drop in trim speed. Quarter to half bar increases the descent to 6 - 800fpm and increases trim to a healthy 'get me out of here' speed. A patch of darker cloud buried in the overcast gave me an opportunity to try big ears plus speedbar in anger. Big ears reduced the 400fpm-and-rising climb to a steady 200fpm, and the addition of a little bar silenced the vario, so I locked my leg straight for half' bar and got a steady 200fpm down.
There is little tendency for the wing to hang back or pitch forward even in very rough air. Roll stability is so good as to be almost excessive. The Kali has to be held in a turn with inside brake. Ease off for a moment and you're back to level flight. This is particularly reassuring in spirals, and a textbook recovery may be made by slowly easing off the inside brake.
Big ears are easy to pull and very little force is required to keep them in. A short pump pops them out again as fast as required. I tried a twoline asymmetric collapse but the Kali was having none of it. The barest hint of a nod. I grabbed an inner A riser and gave it an enthusiastic yank. Still only a little nod. Snatching both the inner and outer A down resulted in an asymmetric nod, turning the glider 20 degrees to the right. The wing really is very tuck resistant and very quick to recover once you do succeed in collapsing it.
Flying badly in air rough enough to cause collapses on several other gliders produced no untoward behaviour. On full speed bar in rough air he tips stayed nicely inflated, even when off-loading from time to time. Pitch control was a little busier than at trim, as you might expect with such a broad speed range and my on-off 2:1 speedbar.
The Kali is easy to handle in a variety of conditions. It is effortless to launch and copes particularly well with tight landing areas. The majority of customers for a wing of this class will be buying their second, or even third, DHV1- 2 rated glider, though there are no hidden vices here to catch the keen first-timer. Performance is a big step up from the Pulsar and is right up with the best in this class.
If you are looking for a new DHV1-2 wing, put the Kali on your list.
We are glad that Ian was so impressed by the Kali. We don't think there is paraglider out there to match its combination of glide, climb, sink rate, speed, launch and all-round flying characteristics, light handling and stability. The Kali is an incredible all-round paraglider and a great deal of thought, research, and testing has gone into the its design.
It's clear from Ian's review that he has gone over the Kali with a fine-toothed comb. As he guessed, it has been derived from Windtech's Tempest. Ian also found that the Kali is more than a match for even the best of the rest in its class. The Kali will give many higher-classed wings a run for their money - but with incomparably better safety! Kali demonstrators are available now for test flights around the UK. Contact us to find your nearest Windtech dealer.
Carlo Borsattino, Windtech and Wave's UK