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Who says flying thermal soarers is boring?

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Simon Chaddock07/02/2020 09:04:12
5711 forum posts
3034 photos

I rather enjoy the exercise of trying to get an 'ordinary' but light plane to thermal.

Not so impossible using E power to get you right into the thermal core (and to get you back home!) but still rewarding to see a prop plane go 'up' with the motor off. wink 2

You can definitely thermal a sub 250 g Super Cub.

Edited By Simon Chaddock on 07/02/2020 09:04:44

Former Member07/02/2020 09:04:22

[This posting has been removed]

Cuban807/02/2020 10:21:14
2956 forum posts
1 photos

I was quite active back in the 80s with thermal soaring and even had a go at some of the more local BARCS competitions. When (as I saw it) the fun element of competition was very much being pushed into the background and I witnessed several quite unpleasant incidents between flyers, sometimes between friends,  who were getting much too worked up over something or other to do with the rules, I gradually allowed my interest to lapse. Last year I had a go on a friend's 3M glider with a small motor to get it up to a decent height and enjoyed the experience very much indeed. A bit like riding a bike, you never really forget, but to get good times one needs to practice and get to know the model's characteristics over many flights and in a variety of conditions.

Those who have flown thermal will know that the gilder is constantly 'talking to you' (albeit visually, if you know what I mean) and by understanding its 'language' and subtle actions, the difference between flying through small areas of good or rising air without capitalising on them is so easy to do. Blundering into a boomer of a thermal and screwing up to altitude is easy, getting out of it is often a different and sometimes terrifying experience. Maintaining your altitude in marginal conditions and moving quickly to avoid sink is where the skill is. And then of course there is landing a large model that wants to keep flying and you want to put it down on 'the spot' without dropping short or usually overshooting (even by a small amount) is another skill that needs to be mastered - some never weakness I'm afraid.

Been promising myself a nice 'Bird of Time' with a motor up front for the good thermalling days or when a change from all the other models is required. I've had my fill of bungees, tow lines and winches, a few seconds on electric power gives you a tremendous launch to as high as you like for sport flying, messing about with all the other paraphernalia is no longer a viable option for me. As for way. Often less really is more.

Edited By Cuban8 on 07/02/2020 10:27:47

Martin Harris07/02/2020 10:23:49
9333 forum posts
249 photos
Posted by Bob Burton on 07/02/2020 08:59:10:

Flying thermal soarers is not boring, but when you put a motor in a glider it is no longer a glider

That's quite correct - it becomes a self launching motor glider.

When I was involved in full size gliding, motor gliders were a compromise and in the minds of many, a different "animal" to a pure glider and most popular as a 2 seat trainer with the capability to operate autonomously or teach field selection. There were self sustaining motor gliders [capable of just about climbing from and maintaining level flight for an extended time and requiring a conventional aerotow or winch/cable launch] which had fold-out engines that were designed to get you home which slightly detracted from thermalling performance but had no impact on lift/drag ratios i.e. distance you could fly from a given height. As there was the psychological benefit of the probability of getting away from a low point, these were regarded by many as a form of cheating over doing the same flight in a "pure" glider even if the engine had not been used.

With a typical 2000' launch, you had a range of several miles to sniff out a thermal in your "proper" glider- or perhaps pull off lower down if you encountered good lift on tow. Decent thermals tend to get going above about 600' or so and below this tend to be bitty and disorganised. At a hill site, there was often the option of hill soaring until getting established in a good thermal.

Contrast this with the typical flat model flying site - the range of search is limited by line of sight and in many cases, no fly zones behind the pilots. While very low wing loading gliders can soar on tiny bumps low down, a reasonable sized scale glider is much harder work to keep airborne until at a fair height for a model.

In these cases, the use of an electric motor is a practical way to utilise the ballast, which normally simulates the pilot's weight, to launch - tugs aren't necessarily as available as at a full size site - and give second chances to find lift within the small operating area available.

While the motor is not being used and the propeller is folded, the aircraft is to all intents and purposes, a model glider with a similar wing loading to the same one without a motor fitted.

Boring? Well I rarely feel the desire to fly more than 15 minutes - and typically 10 minutes - per flight with my main hobby of power/scale models but I have often flown for 30 minutes to an hour or more with a powered glider with less than 3 minutes of this under power.

Edited By Martin Harris on 07/02/2020 10:42:57

FilmBuff07/02/2020 12:10:57
258 forum posts
28 photos

Agree with @Martin Harris. Gliders have to be launched by something - so why not a small electric motor?

I do slope soar with "pure" gliders - but even there I resort to EP ones in very light conditions. Saves landing out! I do try and use power just for safely getting back to ridge height and landings. Honest.

It is strange that my most memorable flights are all lengthy flat field or slope flights - not the ones when wringing out an aerobatic power model.

Thermal flight? 4th Sept 1981. Windless day and the model sagged off the bungee at around 100 feet. Slid to a landing at my feet 90 mins later for my first ever flat field hour plus flight. Used multiple thermals with several scary descents to start again before it was at limit of LOS. So ingrained that I can even remember the exact day!

Slope flight? Too many really! One was a few years ago in autumn, when the slope was shrouded in mist apart from a gap that started about 50 feet above slope face and continued to about 100 feet before more mist. Imagine a large, clear slot above the slope. Launching into the light wind was tricky - as the glider dipped into the murk. A slow climbing turn got it into the clear slot. The trick was to then continuously fly within that area. It required lots of concentration to do this for around an hour. So much so that I was unaware that the sun was starting to burn of the mist during that time. Then suddenly - it was as if the mist disappeared in a moment - and the whole view of the valley appeared in front of the glider. It was magical!

Concorde Speedbird07/02/2020 12:38:18
2734 forum posts
650 photos

Never flown model gliders, but I do enjoy using thermals to take me places...


Tim Kearsley07/02/2020 12:51:13
678 forum posts
3 photos

I fly F5J models and use the motor at the front purely to get me up to altitude. From that point I hunt thermals, like any glider that's been launched by bungee, towed up or thrown DLG-style. I've never understood the purists who complain that it's "not real gliding". I use a vario too - I suppose that's frowned on as well!


Tim Kearsley07/02/2020 12:51:50
678 forum posts
3 photos

I fly F5J models and use the motor at the front purely to get me up to altitude. From that point I hunt thermals, like any glider that's been launched by bungee, towed up or thrown DLG-style. I've never understood the purists who complain that it's "not real gliding". I use a vario too - I suppose that's frowned on as well!


P.S. Sorry for the double post!

Edited By Tim Kearsley on 07/02/2020 12:52:42

Former Member07/02/2020 13:09:23

[This posting has been removed]

Former Member07/02/2020 13:26:12

[This posting has been removed]

Steve Houghton 107/02/2020 14:42:11
1913 forum posts
128 photos

Unfortunately for me most local fields I can use for thermal soaring are really too short to stretch out a full length bungee, but big enough to fly an EP glider, and I have had some great flights with my little 2m EP glider, just managing to bounce along from one low level thermal to another.

David perry 106/04/2020 20:00:14
1054 forum posts
13 photos

I've always enjoyed thermal soaring. Catching a ride for an hour...nothing like it


Speedster25/05/2020 18:06:36
385 forum posts
163 photos

Denmark today laugh

Nice thermals and just wind enough to do some treeline DS with my Arthobby Silent 3,4 M devil

Simon Chaddock25/05/2020 18:55:23
5711 forum posts
3034 photos


That is a very impressive. I suppose it is a form of dynamic soaring but you do need a very efficient air frame to do it at such a modest scale and wind speed. wink 2

Richard Clark 226/05/2020 05:03:40
269 forum posts

I have a 'terminology' problem with these things.

The OP's heading says "thermal soaring" and the video he posts says "glider".

But in fact it isn't either. It's just a lightly loaded, high powered and strongly built powered aircraft so it can't help but have a very broad flight envelope. Very nice, but no big deal - it does exactly what one would expect. If it had wheels it could probably win an F3A competition too if it was flown by a good pilot..

I'm not really into such things but I do have an old Multiplex Grafitti. Quite small (about 70 inch) semi-scale version of a modern 'true' glider but electric with a folding prop, glass/epoxy fuselage, balsa covered spruce sparred foam wings with flaps and ailerons which can be switched to 'flaperons' any time you want and an all-moving tailplane.

When it came out it wasn't very successful. The only motors that would fit and were readily available were the old brushed Speed 400s or 480s and there were only NiCad or Nimh batteries. With its small prop to match the motor it would slowly stagger around the sky after a very slow climb but that's all.

Now, fitted with a geared Kontronik 480 size brushless motor, a 60 amp Kontronik ESC, a big folding prop, and a 3 cell 50C 2200 lipo it's terrific. The fasted and most aerobatic plane on the field and with the flaps and ailerons slightly down and only using the motor for short extremely rapid climbs it will stay up for more than an hour with no thermal assistance. Though of course the battery doesn't last long at full throttle continuously.

But we shouldn't pretend these things are 'gliders' or 'thermal soarers'. And we aren't 'glider pilots' They are just broad spectrum regular model planes. Even my little Sig Rascal can 'soar' on a good day. But please don't get me wrong. The OP's video tempts me to buy  a bigger one

Edited By Richard Clark 2 on 26/05/2020 05:10:57

Edited By Richard Clark 2 on 26/05/2020 05:12:34

Robert Putley 126/05/2020 10:27:03
199 forum posts

I started flying power assisted gliders back in 1991, living in Norfolk and flying solo from home, this was the only realistic choice. Scale jobs up to four and a half metres, down to 50" built up gliders. Had many wonderful flights,and much thermaling. That was fun, when high up circleing in a thermal, a bird of prey or two some times would fly across to join in.. Sometimes it was the other way around.

Cuban 8, I would thoroughly recommend the Bird of Time to you. I purchased a kit (Don`t go near the ARTF) by Dynaflite around for years ago for 99 Euros. It is a lovely aeroplane to fly, powered mine with a 36mm x 48mm inrunner, 10x6 prop, and if I remember correctly draws around 46 amps on a 2200mah 3S graphine which just about squeezes into the nose section. Set the timer for 2` 20" which leaves 30% in reserve. She termals in the lightest of lift, so most of my flights are around one hour. I that is usual with less than two minutes of run time, and leaving themals early.

So, electric assist gliders suit meand even on my scale Discus, using a white Aeronaught spinner and prop, it still kooks like a pure glider.

There is no right nor wrong, it really boils down to what suits you. Horses for courses.

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