What's R/C Sailplanes All About?
Radio Controlled or "R/C" sailplanes are small to large engine-less model aircraft also known as gliders.
These typically are made from a variety of materials including balsa wood, foam, or carbon fiber
and epoxy, in various combinations of each. Sailplanes don't have or need engines to keep them flying, although many use
electric motors or gas engines powering
propellers to 'tow' the sailplanes to a decent altitude. As in real (human piloted) gliders, R/C sailplanes
rely on the same mechanism for gaining and keeping altitude: thermals and slope lift. Some people
think that you can just toss a sailplane into the wind and the plane will just rise, like a kite,
into the air. Instead, a sailplane that has no power towing it is always descending or falling down through the air. If the air below
the plane is rising faster than the plane is falling, the plane will rise upwards, and then the real fun begins...
One of the best things about sailplanes is that they're noiseless, don't produce exhaust, need to continually charge and recharge between flying sessions, or get a coat of 'slime' over every exposed surface of the airframe after being flown.
Alos sailplanes have the distinct advantage over motorized planes, either gas or electric, in that they can in the right conditions, stay up for an hour or even longer. You don't just launch your sailplane and then glide down to the ground. The goal is to stay aloft and that means 'looking' for thermals or flying off of a slope which gives the sailplane lift. Once your sailplane is airborne, regardless of how high, the sailplane may only remain in the air for a couple of minutes or less. If there is lift or the pilot has gained a reasonable amount of experience, the sailplane can remain in the air continuously, riding on that lift...
Once you're in the 'lift', you rise or stay at the same altitude. There is something very special about launching a handlaunch glider in a small field, groping around for lift, finding some and then specking it (making the sailplane go so high that it is a 'speck' in the sky). Once you've done this with a sailplane, you will be hooked into this hobby for the rest of your life. Choose your hobbies carefully.
Sailplanes can be launched from the ground by merely throwing them to get altitude, known to the 'purest pilots' as Hand Launch Gliders or HLG, flying above the edge of windward facing slope, or by using a towing mechanism from the ground such as a long rubber band known as a hi-start or with an electric winch. (You can see a diagram of a hi-start here.) To get the sailplane to a high altitude means attaching your sailplane the line end of the hi-start with a ring on the hi-start and 'tow hook' on the bottom of the plane (just in front of the plane's center of gravity) and staking the rubber end into the ground. Start by stretching the rubber downwind and when there's enough tension (depends on the weight of the sailplane) releasing or sometimes throwing your sailplane up and into the wind. The hi-start will cause the plane to rise quite quickly depending on the weight of the sailplane, the tension on the hi-start, and the amount of wind that is blowing. Launches can be as high as the hi-start is long or even longer under good conditions.
Winch launches can be higher than hi-start launches, and certainly are more convenient, but can also destroy a sailplane if too much force is applied to the sailplane during launch. Typically, there is a foot pedal that allows the pilot of the sailplane control over how much 'winching' occurs during a launch. Tapping the foot pedal can then modulate the force by turning on and off the winch.
Launching sailplanes from a slope can be much easier. You don't need a hi-start or winch, you don't really have to search out thermals, instead you just give the glider a good toss into the wind. The rising air on the slope face provides the lift to keep the sailplane aloft. Keep the plane in the lift and the plane will continue to stay at the same altitude or rise. On good days, the only limitation of duration of a flight is the amount of available daylight or battery power for the radio equipment.
All classes of thermal sailplanes will work well on in a slope environment. The only potential problem about flying, say a handlaunch sailplane, on a slope is the amount of available lift can be too much for a sailplane designed for extracting every breath of lift available. I.E. You can't get the plane down on the ground again easily! For a slope, you can sacrifice lightness of construction and other efficiency in the airframe for a plane designed for speed and strength. It is not uncommon for some slope gliders to fly at speeds in excess of 120 mph or faster as long as the conditions permit this.
Thermal sailplanes generally fall into one of four categories:
Slope sailplanes are in typically two categories:
Additionally, some of these planes can fall into multiple categories meaning that thermal planes can be flown equally well on the slope, handlaunch planes can be thermalled
like open-class sailplanes, etc. Sometimes I like to fly my handlaunch planes on the slope when the wind is light and
I fly some of my thermal duration planes there too. I even tape hooks on the bottom of my
combat wings and shoot them into the air with a shortened high-start
for a quick combat session, when I'm not on the slope.
Here's a checklist of the things you need to do to get started in the R/C Sailplane hobby:
Find a good starter sailplane kit or ARF (Almost Ready to Fly) kit. Good choices for a beginner's sailplane are planes that have 2 meter or shorter wing spans and use only rudder and elevator for controls. For a beginner, there really is only one way to go when choosing your first sailplane and that is to select a plane made mostly or all Expanded Polypropylene (EPP) foam. Planes made of EPP are very durable and just don't break easily, even if you dive them vertically into the ground as they just tend to bounce! This gives you the chance to learn from your mistakes without having to constantly re-build your plane after each flying session.
You should really start with one of the EPP-based planes (for thermaling OR sloping) originally created by Dave's Aircraft Works (and still being manufactured by SkyKing RC Products), such as the all EPP, 2-meter wingspan S1-26.
If you're a 'purist' and would rather build a more traditional kit out of balsa, there are several planes that have been teaching beginners over the years, but they are hard to find as they've been discontinued. Plane kits known as Goldberg's Gentle Lady or Great Planes' Spirit were built by the thousands. If you are really interested in building one of those, you may find a kit on eBay or maybe a local hobby store. You can browse for other 2 meter planes here: other sailplanes.
Don't go wild and purchase a 'full house' sailplane as your first sailplane, i.e. one that has ailerons, flaps, etc. and requires a computer radio to fly. It is ALWAYS better to buy a beginner sailplane and learn to fly before crashing a beautiful, carbon-fiber, $500+ investment into the hard ground. It is good (and more fun) to have more than one plane anyway.
Up until very recently, ARF sailplanes have been heavier and harder to repair than a built-up wood kit or even an EPP-based kit. Recently, however, there has been a rash of new ARFs that have been manufactured in Taiwan, the Czech Republic, and other places that are better built than before, but still tend to be more expensive than doing it yourself. My choice for a beginner is to still build the plane yourself. By doing this you will know more about building and repairing if the plane does crash or you run over it accidentally with your car. The better kits have parts that are laser cut to a high degree of accuracy and usually go together a bit easier. I also prefer kits that have 'all hardware included' on the side of the box. For a beginner, this helps the builder understand what things like 'clevis' and 'pushrods' are and you won't need go on these shopping sprees at your local hobby store, grabbing everything in sight that you think you MUST buy, but don't end up using.
A typical investment for a training sailplane in kit form is about $80-$120 including the kit, covering, glue, and other things that you'll need to finish the plane. Two-meter gliders usually accommodate the standard size radio equipment, which usually has a lower cost as well.
What is newest in radio control technology is the addition of spread-spectrum based radio controls. The big advantage of these 2.4GHz systems is that you no longer have to worry about individual frequencies for each plane or modeler. With one of these radios, the transmitter is matched with a receiver and this results in no possibility of frequency conflicts, unlike the 'old' days of fixed frequencies. The other nice thing about these radios is that each transmitter is essentially in two-way communication with each receiver at a very fast frequency. These systems have less lag and better overall channel responsiveness. Every major manufacturer has their own version of these systems now. Some of the newest popular ones used for sailplanes are: Futaba 6EX 2.4 Ghz, Airtronics SD-6G, and Hitec Aurora 9 spread-spectrum 2.4 GHz radios.
Purchase a radio control system that has at least 4 channels of control and rechargeable batteries (NiCad, NiMH, Lithium, or whatever they have these days - Hydrogen Fuel Cells probably will be next!). Up until recently, you had to spend about US$150 to get a decent radio. But there are some amazing radios that are priced below $100 and still have spread-spectrum technology.
If you spend a little more for that first radio, you can get a transmitter that can be used for more than one plane. These transmitters have 'model memories' where each model can have a distinct profile stored in the transmitter. You won't outgrow one of these radios as you gain flying skills, build more planes, and want more features. But... I probably wouldn't buy the top o' the line computer radio as your first radio as they can be terribly frustrating to setup and program just to get 2 channels working.
You can read more information about radios by visiting the radios page.
Build that plane!
Clear a space in your garage or some nice 'extra' room in your house for a building board that can accommodate at least 3' x 5' of flat building area. (I've built planes on smaller surfaces, but it's really nice to have some extra space for piling all those glue bottles, tape, etc.)
My favorite choice for building a board surface is a ceiling tile used in offices. They're available at most 'do-it-yourself' hardware stores and these tiles are cheap.
Put a nice light above your board so that you can still read the plans late into the night (the 'best' time to work, right?).
Here's some tips for building:
Join the Academy of Model Aeronautics (AMA). They, the organization, are on your side. They lobby for local and international interests with government organizations such as the FCC (for radio frequency regulations), the FAA (for flying interests), and Congress. The AMA is also affiliated with the National Aeronautic Association (NAA) and has representatives for the US in the Federation Aeronautique Internationale (FAI) organization.
The AMA provides for up to $1,000,000 of liability insurance. Be aware that some flying clubs, organizations, fields, and contests require membership in order to fly. You also get a subscription to a magazine known as 'Model Aviation' which contains up to date information about the AMA as well as kit plans, articles, and some of the latest tips from modelers all over the world.
You can join AMA by contacting them at:
Academy of Model Aeronautics
5151 E. Memorial Drive
Muncie, IN 47302-9252
Now learn to fly... BUT, most importantly:
GET HELP FROM AN EXPERIENCED FLYER!
Most R/C pilots enjoy helping new people into the hobby and you can really get a tremendous amount of experience by just talking to these 'veterans'. Most beginners that have had help on their first flight get to take their plane home without having to carry it in a bag, also known as 're-kitting' the plane.
Some first time flyers assume, since they have had flying experience in full-size aircraft, that they can control their model the same way. The problem isn't that you already understand what it takes to fly, rather you need to teach your fingers or thumb to fly. Plus, the plane flies away and towards you, you need to be able to look at the plane and then determine what to do (with those fingers). Trust me, it isn't as complicated as it sounds, it just takes a bit of practice and it is absolutely more fun to fly a plane than it looks!