Discovering the Discovery & it's Sisters.       At the Picolight Flyin Andrew Polidano and I had the opportunity to check out the upcoming new range of picolight powered flying machines from Airtime Products. I put some hours and many launches over three days on the Radne Racket powered Discovery paramotor that is for lighter and medium weight pilots. More on that later. One interesting new beastie from Airtime is their Powerlite trike for hang gliders. It's powered by a 172cc Corsair engine that has enough oomph to give it a decent climb rate so that it gets off and away from the ground quickly even in nil wind. It folds up small enough to put on a roof rack, and on the Fun hang glider it looked like about as much easy fun in the air as you could possibly hope to have. The launches, landings and the flying looked so easy and enjoyable that it would have to be the perfect machine for those that just want to have fun in the air. Airtime have also released a folding prop for their Explorer motor harness for hang gliders. We got to see that there could be a second reason for puting a folding prop on a hang glider motor harness. One pilot who had just bought a folding prop was having trouble launching his newly acquired SX6 with the motor harness in light wind. He blew a launch and fell over. The folding prop was still rotating when it hit the ground but was completely undamaged. We figured that the forward speed folded the prop back on impact and so prevented it being damaged. From the way it hit the ground we expected it to have been damaged for sure. The Radne powered Discovery paramotor is obviously a well thought out machine. When it sits on the ground the propeller is not vertical but leans forward. This is to allow the pilot to sit in the harness on the ground and clip in etc before standing up. The fuel tank is easily disconnectable and removable so that if you run out of fuel & have to outland, you can disconnect the fuel tank and take it to get filled. You can also easily remove the fuel tank for storage and transport etc. The cage is in four parts and packs up incredibly small. The top half of the cage is quickly and easily removed to halve the height of the paramotor to make it easy to fit in a station wagon. You could probably even fit it on the back seat of a sedan. With the cage fully broken down you could put the whole thing in the boot of a sedan. The powder coated aluminium cage may not be as durable as the stainless steel cages on some motors but for me the weight saving makes it worthwhile. The propeller is a high aspect ratio carbon fibre job that is 123cm in diameter. This type of propeller is more efficient and quieter than smaller thicker props and so can give just as much thrust with a smaller engine. The reduction drive is via a toothed belt that should be more efficient than a poly V belt and lighter than an enclosed gear drive. There is a centrifugal clutch, so the parablender doesn’t turn on idle. The weight of the paramotor was wonderful. We put it on the scales and it was two or three kilos lighter than my Fly Products 115. The 120cc Radne Racket engine on the Discovery we flew had a new expansion chamber and after muffler that made it much quieter than the Radne used in the Explorer motor harness. Bob & Co were not happy with the expansion chamber/muffler on the motor I flew and have since decided to change to a new expansion chamber/muffler from Radne. Bob tells me the new setup gets maximum power out of the motor while staying just as quiet. He said it is not as sexy looking as the one I flew with though. The Discovery also has a carburettor inlet silencer (airbox) for added noise reduction.  The first thing I noticed about the Discovery on the ground and in the air is how simple and easy it all is. I couldn't quite figure out why but the low attachment points & upside down throttle lever made grabbing the risers for forward and reverse launches simpler. In fact both on the ground and in the air the set-up feels natural and uncluttered (unlike my Fly). I did discover that the harness set-up is rather crucial. Depending on which hole I had the risers in and how tight I had the leg straps I could either stand up fairly vertical for landing or not. Also tightening the shoulder straps made a big difference to how it felt on my back on the ground. It still is not quite as comfortable on my back on the ground as my Fly but it is close.  In the air the experience was the most similar to free flying that I have experienced. The pivoting under arm bars (like the PAP, Vortex & Tornado) give weight shifting and feedback from the wing. Don't expect the weight shifting to be quite as effective as for free flying though. The low attachment points however allow you to rock forwards and back more than with high attachment points but it didn't seem to cause any problems or discomfort. In fact I flew it in strong wind and ground turbulence strong enough to get a thirty percent asymmetric collapse (on my Arcus) at one hundred feet, and I felt as comfortable as if I was free flying. Note that it takes more turbulence to make a paramotor wing collapse under power as it has a higher angle of attack due to the thrust. Like with free flying you can also tighten the chest strap a bit to make it feel more stable. Andrew found the strong turbulence a bit uncomfortable until he tightened up this strap. The under arm bars tended to bump against the underside of the arms in flight. This will change in future, as the Airtime team will be puting in curved bars to increase the clearance and minimise any discomfort. Both Andrew and myself didn't notice much torque effect (the tendency for the motor torque to induce a turn) on the Radne powered Discovery. Airtime seems to have struck on an interesting method of torque effect cancellation. The torque rotates the motor a bit on your back, which offsets the thrust line to almost completely counter the torque effect at all throttle settings. Bob since tells me they have made a further improvement to decrease torque effect on both the Radne and Corsair Discoveries. One thing that I had wanted to test on a low attachment point motor was how they behave with roll unstable paramotor wings. Some paraglider wings are not very suitable for paramotoring because they exhibit roll instability in climb. The wing can build up a roll oscillation where the wing moves from side to side above your head by up to three metres. I think it is due to the roll rate of the canopy synchronising with the gyroscopic precession rate of the propeller/motor. This roll effect cannot be cancelled with the brakes and only disappears when the throttle is reduced. At the flyin a couple of people had wings (Edel Atlas & Quantum) that exhibited this roll instability on their motors (DK & Fly). Andrew (I am too light to test large wings) took both of these wings for a fly on the Discovery and neither of them exhibited any significant roll instability! The Airtime team haven't yet done the tests but with the large fuel tank, efficient prop and small engine I would expect to get about four hours out of a full tank of fuel. This is the first paramotor that I have test flown that I would jump at the chance to swap my Fly Products 115 for one. The Discovery paramotors that Andrew and I flew were pre-production prototypes, and as such can't be considered a finished product. The motor that I flew had been re-ported as an experiment. They will go back to the unmodified engine as it made mine almost as difficult to start on occasion as my Solo engine. Once Bob showed me the right starting technique however it got much easier. Bob said to ask any Explorer owner how easy their Radne is to start. Certainly the 120cc engine with automatic decompressor is very easy to turn over for starting. Thermalling the Discovery was not very different to free flying. Once they get the inflight pull/kick starter done this is going to be an amazing machine. Bob told me that Radne will be bringing out an electric start version of the Racket. So even lightweights like me may be prepared to have push button starting if the total weight is no more than my current pull/kick start paramotor. Andrew also flew a Discovery prototype intended for heavier pilots. It had a Simonini engine. Airtime are changing over to a Corsair engine as they feel it is better. We can't really review the Discovery for heavier pilots at this point, however there were two significant differences that the Airtime guys are working on to improve. ie The more powerful engine did exhibit significant torque effect, and the standard Corsair engine is quite loud. I recently received an email from the designer of the Corsair engine saying they are working on making it quieter. The Airtime team, Bob & Bud Bauer (pronounced "Bower"), and Bill Link impressed me as nice guys with the sort of determination and skill required to produce equipment that could make them the "Moyes" of the powered flight scene worldwide. It's great to see such world class (maybe even world beating) quality being produced here in Australia. The Airtime team have really done their homework on these machines. I have heard stories of a humungous pile of paramotor cages and frames from all the previous prototypes they have made. By the time this comes out in Skysailor, Airtime should have gone into production with the finished Discovery. see: www.airtimeproducts.com