Original text by Stephen Green, Issue 70 RCMN

Minor changes to text by Hayden Daley March 2009

Recently we organized a big day out of slope soaring and sure enough the day arrived along with very inclement weather and weather radar showed our favourite slope on the east of Melbourne was socked in. There were four of us on standby and we decided that an ascent up the slippery goat track in a 4wd was a bit risky and two of us decided to go it alone to Mt Hollowback, an alternate site near Ballarat, 100km east of the city of Melbourne. The climb is easy and safe there, straight up a bitumen road built to provide all weather access to the collection of radio towers and our arrival at the top was greeted by a 20 knot southerly and showers. The wind stayed straight and strong and the showers receeded and we ended up having a great day, flying combat wings, aerobatic models and I also threw a small electric powered twin just to see how it went.

One of the enjoyable aspects of flying a glider of a slope is that it is always a work in progress. The wind can change strength and or direction plus the sun could go behind the cloud and the temperature drop can change things as well. The lift band can move in, or totally disappear for a few minutes. Depending on the type of conditions there is times even when the wind is strong and that your model may scratch for lift. Starting with a simple two channel thermal soarer, a lot of fun can be had for a 200 dollar outlay. If you decide to give slope soaring a try, what can you expect when your new glider is launched of a hill? Assuming you have started with a basic model and there is a steady and sufficient breeze it should fly out and start to go up. Keep heading into wind for a few seconds, sort out aileron/rudder trim then look at the pitch. That function sort of replaces the throttle stick and if the glider is still climbing push some nose down trim and it should start to pick up speed. Turn along the slope and follow with a few turns , initially into the wind, fly outwrds do not turn the model toward the slope when turning. Fly along the push the nose down and the the glider will accelerate then maintain a level flight line (not climbing or diving) and you should notice the nose down attidude. To maintain that speed retrim so you don’t hold any elevator and by using the elevator as the throttle, by changing from speed trim or potential trim you can convert speed into height then height back into speed. You are know in to slope soaring!

Turning in towards the slope in known as being dangerous but that is not completely true. Provided you allow for the higher ground speed (flying downwind) and make sure there is enough room avoiding what is a pilot induced phenomenen , the down wind crashing can be avoided. If you have miscalculated and start running out of room the secret is to not pull on the stick to tighten the turn as it is very easy to stall heading downwind. Roll it over a bit more and keep the nose down as much as possible and keep the sailplane moving. If the model hits the hill the outcome is still often better than stalling the thing in. If it gets blown overhead, behinds the hill the air gets very and this is where you change trim, convert height in to speed and get out of there. If the model is flying fast it will get out of the turbulent air quicker. The faster the sailplane the less time it is in rough, turbulent air.

When at the landing point drop it in with a dab of down and with either method dont worry to much about the flare, get the plane where you want it, a foot above the ground then plant it on aircraft carrier style, still moving and then let the model slide. A basic rule of thumb the windier it gets the less you want to hold of and flare. How hard is to hard? Trial and error has taught me to thump the sailplane in until the model breaks then back of a bit next time, seriously the most important thing is landing with the wings level. Catching a tip and cart wheeling the model, if the model flys too slowly the wind will pick the model up and blow it way and that’s bad. Try for a firm touch down and hold down elevator until you collect the model, after it has landed..

Once you get a taste with a warm breeze blowing and some relaxing soaring by hunting each way along the slope face, after putting around alone the first step towards possible slope soaring addiction is organizing another day with someone else, somewhere else!

One day it is highly likely that you will also experience the disappointment of arriving to no wind and no slope that suits the wind direction on a local slope or the planned site has bad weather, rain etc. In order to get the best conditions you should organize the group to be on stand-by for a few days and when that doesn’t work you will need different models for different conditions including an electric model for really light days and then go in any conditions. Be warned if you take the next step and start buying slope soaring models maybe you are becoming slope soaring addicts like me and start slope soaring with other people with the same problem!

Over the Top

Years ago I bought an old Yamaha RD 350 twin cylinder two stroke road bike from my brother for a hundred dollars. The deal included a leather jacket and boots and after a couple of goes around the street I –purchased some additional accessories. They say If you have a ten dollar head then purchase a ten dollar helmet, so I bought a a new helmet, the best I could afford, In fact the best in the shop and some expensive, good quality gloves. My mate then rushed home picked up his bankcard and bought a road/trail bike. After some riding the other guys bought similar bikes and then I needed a trail bike. On the way to the store to pick up my new Yamaha bike I was flogging the guts out of the old bike and the rings let go. I traded the bike and got my hundred dollars back During many weekends away a constant subject of discussion was how many different bikes did you really need? I don’t ride bikes anymore but the subject often gets discussed, how many slope soarers do I really need?

What equipment do you really need if you intend to seriously get into slope soaring? Depending on your level of addiction , time and budget the short answer is that two pilots can have a great day with three models each. Fifteen sounds a lot, however some of my slope soaring friends have this many; and more and I have begun to build up of fleet of more, new, modern slope soaring models.

My squadron consists of a Zagi combat wing, the Parkzine Striker F27 electric combat wing, a slippery aerobatic four channel slope sailplane and the Violet, a basic two channel glider. Recently I purchased an R-21 a basic handlaunch sailplane when there is no wind, only thermals. It weighs 89 grams and my old chuck gliders that I built when I was a child weighed more than this particular glider.

A multi seat van comes in to its own when you get at third member of your secret society because there is still enough room for his/her sailplanes and a designated driver so the returning home celebratory drinks can be enjoyed on the way home, you don’t have to drink alone. One of the must haves on the sights where I go soaring is road access, carrying all the stuff up large hills takes a long time and may require two trips, walking for an hour is not on, road access only. A few years back after lugging five models a kilometer to the slope, having a computer radio was a necessity, carrying four radios was basically impossible, so the need for a computer TX when slope soaring became a prerequiste. Being on the one channel however sometimes limits your, your friends maybe on different channels but often I have arrived and another group is there and someone is on the same frequency, having a great time while I watch!

Presently I am using the new Hitec Optic 6 with frequency synth so with some RX crystals that is a modern way of avoiding that potential problem but having two radios on different channels and splitting the fleet onto two different channels in case this occurs. Another vital piece of equipment required is a good fast charger because with one hour flights and many models on the one radio you will, definetley need to charge you equipment to fly all day. Coastal slopes are my favourite but inland slopes also offer the possibility of thermal soaring and watching the model climb way above you after hooking in to a thermal from down low on the slope is very satisfying. There are a few ways to find slope soaring sites, try the local hobby store or a soaring club. Bribery can work, finding a hill and offering the owner a gift, alcohol usually works and with the promise of shutting the gate so the cattle wont run away, you can find your own slope.

Slope combat is the best fun but having an absoloute ball smacking each others machines out of the air, don’t forget the colours on your model, it might crash….I wont name the guy, because he has a lot more gliders than me and he lets me fly them but he burst into hysterics screaming out that one of the combat wings had hit a tree behind the slope and the response from another person was “don’t worry its yours” was the reply. He had taken his eyes of his model and flew another long enough to crash his wing. The net result from slope combat is a sore stomach from laughing to much and with three or more combat wings the laughing is incredible. The general public think you are mad but a complete model, servos, battery etc is around two hundred dollars. Cheap kits like the Model Flight Taipan cost around $65 for a complete kit, everything required for building.The models are virtually indestructible although the performance does slowly deterioate as the front of the wing is knocked out of shape after many combat bouts. Take along spare servo horns, another servo or two and more tape for really bad hits. Another vital factor for combat survival is a recessed switch that can be kept clear of combat hits so the model does not switch off when hit and crash.

Our rules are simple, a kill is obtained if the enemy is hit and knocked to the ground and the other model survives the impact. We don’t try for head on collisions because the models last longer when hit from behind and above. Anyone who has walked down the slope face to retrieve there model from the slope will testify that thre are certain dangers with that task. When my model gets knocked out of the air I offer the victor a free launch, inverted if they fell to the ground near my crash site. A stick to hit the other models is also vital as they fly over trying to frighten you into giving up.

The price of electric soaring gliders has dropped so much that if anyone asked me, I would recommend electric as the way to go as a first model. A two channel model is okay up to fifteen knots and a four channel aerobatic model if you have some RC flight experience. The obvious advantage electric power offers is in marginal lift and the motor can operate preventing an out landing at the bottom of the hill and the batteries provide ballast when the wind picks up. Models of this type will cope with conditions from zero to twenty five knots easily and you are not left stranded after a long drive to the site too find bad conditions, you can still fly.

Although my very efficient Simprop SC300 will maintain height in ten knots you do have to concentrate a lot when hanging above the stall a meter off the deck so the level of fun reduces. The model also copes with thirty five knots and would be okay in winds stronger but the lack of penetration in heavy conditions soon makes it boring. Ballast is the answer in these conditions but there is no room in that particular design so each design does have limitations but a dedicated slope design, usually molded will perform a lot better. For interest sake I have heard of people taping ballast from F3B comp models to the bottom of there sailplanes, another way of gaining more weight.

With exception of slope combat most of my mishaps have occurred when the glider and the conditions did not match and having walked down the hill many times to collect a model in bad weather, electric power really helps. If conditions become marginal a wider selection of types reduces the risk and I learned this the hard way after losing my 5kg DG 500. A sudden 45 degree wind shift and the DG was in trouble, I trimmed for minimum sink and began searching for some lift, any lift at all. The model got too slow and tip stalled, an electric option would have saved the model. A series of ear shattering crunches lead me to believe all was not well with the DG500 and one of the guys yelled “Don’t worry Greenie, its okay you didn’t kill someone”. The most memorable of many slope flights was three of these large models all carving up the slope from a kilometer in each direction. When I purchase another expensive scale model I will be very sure of the lift before launching.

My favourite wind strength is around 25 knots as it offers the opportunity of great lift and high speed runs and endless aerobatics. You don’t lose time gaining height for the next pass, just trim for speed and boom around flat out at crazy speeds while still climbing. Landing in these conditions can be tricky and it can be hard to land these quick models in strong conditions, side slipping works; the best answer is models with four servo wings and land with crow braking.

The SIG Samurai is an old design, very innovative when first released, it had pitcheron control, no elevator or rudder but it is so slippery landing becomes a chore. Lots of times I had to go around and try again,a real pain when it begins to rain. If you have the courage you can hop in the car, hang the aerial out the window and not be beaten by something as minor as rain!

Most of the new all molded sailplanes are so good they perform well in all conditions. With Vtail and cross tail models with a four servo wing these models are the best slope soarers. They have crow settings, elevator to flap mixing, camber change and with the right servos are virtually unbreakable in the air no matter what the maneuver performed. To me these are the ultimate, in extreme wind conditions with full ballast, 200kph+ looks good and feels good to perform these high speed passes. At the top end models made of molded construction can cost above $2000 but you get plenty of bang for your buck. I had a flight with a friends Caracho F3B model and the performance was staggering, this model is an older design from German F3B champion Martin Weberschock, and he flew this design for years in F3B events and when the design became available my friend Graheme Goodson bought this model from a friend. It had expensive competition wing servos, was a full carbon lay up the model was bought to compete and when sold the person who owned the model had stopped competing and sold the model. What amazed me was the model was designed and first flown in the mid nineties and the performance was to say again, staggering. If you wish to buy molded models and are prepared to go with a little older F3B models as slope soarers, bargains can be had as people update and need money quickly as models from overseas arrive and need to be payed for. Any F3B model from 1997 onwards will perform admirably as a slope model however be careful of repaired molded models, try and buy an undamaged molded model and find out the KG torque of the servos installed you will need 3.5kg+ for extreme slope soaring of these models and metal servo gears. RC trading pages are the place to find second hand molded models.

To go sloping that sort of money on exotic machines is not necessary as I said previously there is a lot of fun to be had even with simple, cheap models and I hope this text gives you enough information to try sloping, enjoy the fun and enjoy a day out with mates having fun in the hobby we love. Slope soaring can be how you make it to be, buy a combat wing, try the model at a good slope and find this often over looked exciting type of RC soaring.

Stephen Green

Minor text changes Hayden Daley

March 2009