PARAGLIDING IN SA  |   FLYING SITES  |   REVIEWS  |   AIRLORE  |   STORIES  |   GALLERY |   CARTOONS Independence RADICAL December 2001 by Greg Hamerton Greg has been flying since 1992 and has flown over 100 wings. He prefers responsive handling and agility but rates passive stability highly as he enjoys taking photographs and snoozing whilst gliding.  Visit www.windmaster.co.za for all your INDEPENDENCE equipment in South Africa Michael Nesler can claim an impressive design history. Since 1986 he has been involved in more than fifty different models including early experimental systems with valves, inflated tubes and extremely high aspect ratios. Amongst others, his portfolio includes the UP Vision Classic, Escape, and Cab, the latest Perche range, Wings of Change and the current Edel range (Prime, Promise, Control, Confidence, Excel, Millennium). Most of the big names in paragliding manufacture have benefited from Michael’s CAD software programs. In 2000, Michael began conducting his own R and D programmes independent of manufacturer commissioning, and by 2001 he and his testing colleagues Christian Amon and Stefan Silbernagel had two new wings ready for certification. But it was only when they joined forces with financial partner Stefan Kurrle of Fly-market GmbH (owners of the Perche brand) that ‘Independence’ was born. Their first serial class glider, the Radical, was DHV 2/3 certified in June 2001, soon followed by the DHV 1/2 Dragon. I got the Radical in time to practice for the All Africa Open , a CIVL Cat 2 competition known for consistent, big tasks and hard flying. This year at Porterville was exceptionally good - a weak inversion meant good blue thermals of 5m/s and climbs regularly to 2000m+. The stage was set for some rowdy racing. The tasks ranged from 50-83km, and 15-40% of the field reached goal daily. CONSTRUCTION : The Radical’s line plan is simple and efficient, with 3 lower lines each splitting into 3 uppers. Every third rib holds the line attachment points, and is braced by a continuous V-rib on either side. The leading edge is also extended underneath at this point, to almost cover the opening of the triangular cell formed by the V-ribs. Radical leading edge detailThe unique leading edge design is born from Michael’s personal experiences with closed cell prototyping. ‘We made some of the first serial gliders on the market with closed cells (Edel Excel and Millennium 2000)’, Michael told me, ‘and the first Radical prototypes also had closed cells. But closed cells have more problems: the opening is very dynamic, the brake pressure in hard conditions is very high and during testing we damaged some closed cells (due to exploding near the nose). To get the same aerodynamic result the solution of the half closed cells comes very near.’ All Independence gliders have a grey leading edge to identify the brand. Apart from being an image tool, grey is one of the most resistant colours to UV damage. Independence gliders are manufactured in Sri Lanka by Stefan’s brother, who owns SkySports, a well-established paragliding constructor. HANDLING : The Radical offers good ground handling, and can be recovered just by leaning into the wind. It comes up in a nice steady arc. Once in the sky, the character becomes more demanding. The feedback is sharp and a little unnerving at first - the kind of feeling you get when a fish bites your fishing line but doesn’t take the bait. And when you're flying the mid-summer sky at Porterville, running low on the ridge to gain speed, there are many, many fish. But while you’re fed a steady stream of information through the risers and brakes, the wing doesn’t collapse much. I began to settle into the glider. The Radical has a long-lined grace and precise turns which I found enjoyable, and possesses enough energy retention to make thermalling an active game. Despite the moderate to strong brake pressure, there is an uncanny similarity between the Radical and the Airwave Magic. Laid out on the Magic, it looks like they are cut from the same pattern. Only a fraction has been shaved from the chord near the wingtips of the Radical. The lines are 5cm longer on the Radical all around, and the cells are 5cm wider. Since both wings were conceived at a similar time it would be churlish to take the point any further, other than to note that such similarities in modern wings highlight the cross-pollination of good design ideas. SAFETY : Experimenting with the SAT for the first time can lead to some interesting manoeuvres (acro pilots can smile knowingly at this point). I often saw the word ‘Radical’ flash past my face as the wing dived asymmetrically out of a messy spin. The wing certainly generates huge amounts of energy during off-balanced rotations, but considering the treatment at the time, I couldn’t really blame it. When flown normally, the Radical behaves well, and doesn’t collapse unless the air is ugly. The wingtips sometimes initiated ‘shock reinflations’ from big collapses, sometimes the wing turned and dived, swinging out at 180 degrees. At other times the tips showed delayed reinflation tendencies (usually during smaller tip collapses). This inconsistent behaviour left me uncertain if the wing was designed to give a slow, gentle reinflation or a rapid, strong one. Nonetheless, in all cases counter-steering was easy and showed no tendency to stall, so for the active pilot the Radical would present no problem. Front tucks reinflated first in the centre, then cleared spontaneously outwards to the tips in a mellow way. During big-ears descents, the wing showed no tendency to stall (apart from a little ‘flapping about’). B-line stalls were simple. One thing to note is that the Radical does not like to have a light loading - the DHV reports that it stalls early if unloaded and that the brake travel becomes ‘slight’ in turns. PERFORMANCE : At trim speed, the glide angle seemed average for its class. According to Michael Nesler, ‘the Radical is optimised for 45 km/h. At this speed the glide ratio is maximised, the stability is high and reinflations are fast and safe. The Radical is designed to be flown at the upper indicated limit. With a competition harness a pilot should easily reach 50km/h+.’ Independence advertise a top speed of over 55km/h. The glider has a trim speed of 37-38km/h and a short riser travel on the accelerator system (14.5cm). Since the B’s are also kept very close to the A’s (which I suspect improves stability but reduces top speed) an acceleration from 37 to over 55km/h seemed unlikely. When I tested the standard-looking progressive speed system, I recorded much lower top speeds at 1000m asl. I asked Michael Nesler if there was something I was missing in the design, or if there was a different riser set available. Michael told me, ‘We measured the speed at Krippenstein, Austria, at 2500m over the lake, with a Renschler SOL 17 connected to a GPS. On the Radical L the maximum speed with my weight (126 kg - just over the max. weight) was 55 km/h, decreasing at lower altitudes to 52 km/h. If I am sitting normally (semi-reclined) I loose another 2 km/h. In case you use the offshore riser version it is easily possible to fly much faster as this riser has more than 25 cm travel.’ 25cm travel? A-ha. That explains the ambitious 63km/h quoted as their ‘offshore maximum speed’. You’re never going to see 63 km/h on your rated Radical with only 14.5cm of riser-travel. The DHV confirmed a trim speed of 37km/h and a max speed of 54km/h on the Medium. From my experience, you’ll only get close to that if you’re high, loaded to the max. The first bit of speedbar doesn’t seem to have much effect, and although the speed system keeps the wing stable, it does not boost the speed a lot. I floored the bar for five minutes on a long, high glide to goal during the second task, hoping to overtake some of the lower pilots from my commanding position at 2500m asl. We were over the little town of Eendekuil, a cluster of sheds baking in the patchwork of golden brown fields. We had 10km to go over the flats, and although the wing didn’t ‘blow out’ in the moderately thermic air, it never averaged over 50km/h. When we closed on goal, the sting in the tail struck - a lumpy headwind reduced our progress to an agonising snail's pace. I managed to hold my position against some serial class wings (Argon, Bagheera) but could not match the Boomerangs to the finish. SUMMARY: After 13 hours of airtime at both Lion’s Head (cruising over the ocean for sundowners) and Porterville, with a few days of competition-flying thrown in for good measure, I have to say the Radical is only suited to the more experienced end of the serial class pilots, mainly due to the direct feedback and long-lined movement. Its precise turning behaviour is a pleasure, although the brake pressure does build up during long flights. For retired competition pilots and XC pilots with dusty boots, the Radical scores points with its agility, easy launch characteristics and responsive handling. Thanks to GPS scoring, I was able to overfly the goal line, and continue with xc for another hour to reach 93km. Yeah, I was beginning to trust the Radical, and as the afternoon wore on, the feedback smoothened out. There's nothing quite like cranking up in a convergence line, while you watch the hot and sweaty pilots coming back along the route in the recovery truck, far below your feet. TECHNICAL SPECIFICATIONS : Radical wingtipVisit the (German) Independence website : www.independence-world.com To learn more about Michael Nesler and the Professional Flight Team visit www.pf-team.de Many thanks to the Independence importer for the wing : Deon Cilliers - +27 (0)82 4601608 or email independence@skybirds.co.za RADICAL (DHV 2/3)           M       Projected area (m2)           -.--       Flat Area (m2)           26.15       Flat aspect ratio           6.0       In-flight weight range (kg)           80-105       Claimed Trim / Max speed (km/h)           38 / 55                           Airborne reviewer (kg)           97       Vmin in review (km/h)           --       Vtrim in review (km/h)           38       Vmax in review (km/h)           48                           Altitude of review (m above sea)           1500       Air pressure Qnh (in hPa)           1024       Air temperature (degrees C)           16       Correction factor* for speeds           1.00       * 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'. Don't miss out! Get the next paraglider test as soon as it's released, by JOINING OUR MAILING LIST. You might also like to read: Other paraglider reviews on this website.