Slope Soaring


Hi, I'm Rob.C, an un-lapsed long serving Bloobird who joined at the very point of inception of the club about 1971-72.




Going back to those times Bloobirds had a very active Slope Soaring and Gliding wing but that's changed a bit over the past 40 years.  Slope soaring is my first love and I've always felt that if financially or for the lack of time I ever needed to choose between the various disciplines of model flying then slope soaring would be my first choice without a doubt.   One of the fundamental facts about model flying is that we are always at the mercy of the weather and there's nothing more frustrating than a beautiful summers day topped with a 30mph wind to keep you grounded.


Why should you take up slope soaring?


You will otherwise miss out on what can be described as the aeromodelling equivalent of motor cycling in getting a real adrenaline rush by standing on the top of a hill in the bracing wind, flying your model at speed only a few feet from your face.  There is also the dubious bonus of the ground being a lot lower than at the strip!  So, if you want to be flying when the weather will not allow you to fly your usual models then slope soaring could be the answer you are looking for.   Another bonus of this type of model aircraft is that as there are no engines then fuel costs are non-existent.


So How does slope soaring work?


Some of you may know this but just in case you don't heres how.




Slope soaring uses the principle that when wind travels over flat land it gains momentum, once this wind reaches a hill it must rise up and in doing so creates an upward airflow (updraft).  This updraft exceeds the glide angle of our glider and thus lifts the glider up. The plane can therefore stay up as long as the wind continues to blow.


One other effect of this air travelling up the hill is that it displaces the air above the slope which otherwise would not need to rise.  This has a two-fold effect in that it increases the size of the lift area for us to fly in and also the wind speed at the ridge.


Still not convinced? Then take a look at some of the video's on the Slope Soaring links page


We fly in this rising air and therefore need to choose a suitable model to suit the lift conditions on the day.  Generally speaking the parameters are pretty wide and a couple of well chosen models will cover virtually all conditions. 


Low wind speed equals less lift requiring a more efficient glider, or a floater.  Great_planes_fling.jpg


High wind speeds, equals more lift and requires a glider designed for slope soaring.




Even higher wind speeds, and you can even fly a house brick or if you're really into it, a thousand quid glass ship!




In the end there's no need to worry about what sort of glider you need, because if you only go to the slope when it's too windy to fly from the club strip, then our local slopes will be 'working' fine and you will only need one model, a Zaggi !




Restrictions, what restrictions?


Well there aren't any really, it's simply a question that in order to maximise our flight log we must simply choose the model, and the discipline to suit the wind strength on the day you want to go flying.  Having flown most types of R/C models, I've found that gliders in the form of slope soarers do offer the widest range of practical flying speeds and therefore the ability to cope with the wind.  They are after all, designed that way.  You can fly a slope soarer from zero wind speed right up to the point of being blown over, and if you find you can't stand up then stand-back from the slope or hide behind a bush or something!