Getting Started

by Lawrence Doan

"Hey man, this doesn't sound like the rule for a loop."

- Richard Bach, Jonathan Livingston Seagull

If you're reading this, chances are that you already know that you want to learn to fly RC sailplanes.  You've seen someone fly, or read about it. You've looked around on the web, and found rcgroups.com, and this website.  There's so much information out there, but how do you really learn to fly?

There's an excellent (and free) book on this subject: The Sailplane and Soaring Manual. The book is out of print but you can find used copies on line at Alibris Books, And you can view it online: Details | Download

Go ahead and do that.  Then come back.

Ok, you're back.  The book is slightly dated in that it doesn't talk about the latest radio technology, but the sailplane doesn't care what radio is in it, so that's not a problem. The Sailplane and Soaring Manual is comprehensive in sailplane construction, radio installation, trimming and flying and it's hard to beat.  What we'll do here is supplement it with some things to do *before* you get that first airplane.

"This is what we call a wing."

Learning RC soaring, like anything else, is really learning a new language.  There are words to learn - wing, center of gravity, thermal, dihedral - but there's also a grammar to learn to connect those words together.  What is sailplane grammar? You'll need a tool to learn it, and it should be the first purchase you make in the soaring hobby:

Introducing the Humble Jetfire

The Guillow's Jetfire has been around seemingly forever.  Available in toy sections and hobby shops everywhere, it costs from $2-$5.  In the Seattle area, Galaxy Hobbies, R/C Hobbies, and Snapdoodle Toys all carry them. Fred Meyer has them seasonally in spring and summer, and even ACE hardware stores have been known to keep them in stock. Go get one.  Heck, get four.  But make sure they are Jetfires, and not Starfires or Sky Streaks or anything else. The Jetfire consists of a wing, a fuselage, a vertical tail and a horizontal tail.  It also includes a pilot figure/canopy.  These all function (except for the pilot) as they do on every airplane ever built. Assemble your Jetfire according to the instructions.  PULL the wing through the slot.  Adjust the wing to the forward edge of the slot. Place two fingers under the wing, one on each side of the fuselage. Find the point where it balances and the fuselage is level.  Mark that on the fuselage with a pen. Similarly, balance the plane and see if it wants to tip left or right.  Slide the wing slightly to the right if it tips left, and vice-versa.  Don't worry about getting it perfect, but make note of a heavy wing.  (If it's really out of balance, try another Jetfire. It's rare, but it happens.)  Mark the wing so you can put it back if it gets bumped out of place. You have now found the Center of Gravity (CG) of your plane - the critical balance point.  You'll hear a lot of it later, where it should go and all that.  Don't worry about that now.  Trust that that Jetfire has it in the right place.  Later, trust that the designer of your RC plane has marked the CG in the right place, too.

The Art of Throwing a Glider

The Jetfire will teach many things, but the first lesson will be how to throw a glider.  A good launch guarantees a successful flight. This is because _gliders fly themselves._  Your job as pilot will be to guide it to lift and to a safe landing.  Let the airplane take care of the flying. The trick to throwing a glider is to push it straight ahead, and slightly down, without any tendency to spiral it like a football. Hold the Jetfire under the wing near the CG with thumb and forefinger. Hold it gently.  Raise it to eye level, keeping your forearm vertical. Make sure the wings are level.  Bring the plane back towards you by bending your elbow only, then throw the same way - elbow only. Darts players will know what I mean.  Don't snap your wrist.  Release the glider with the wing and fuselage level. The glider should fly straight away from you.  If it falls to the ground, throw harder.  If it starts to loop the loop, throw more gently.  If it slams into the ground, you're letting go too late or holding on too tightly. If the airplane gets knocked out of alignment, be sure to put it back before you throw it again. Practice until you get a consistent flight, even if it curves to the left or the right.  As long as you get the same flight over and over, you're doing it correctly. When you find the right throw you'll find that you can feel when it just wants to lift out of your hand.  You've found the _trim speed_ of the Jetfire - the speed where it naturally wants to glide. Any faster and it will climb, and slow down.  Any slower and it will fall to reach that speed.  In either case, if it doesn't hit anything, it will settle down to that same trim speed.

The Science of Trimming an Airplane

Now that you have a consistent launch, it's time to correct any tendency for the glider to turn.  Note which direction it turns. Make sure your launch doesn't favor one wing down or the other. Hold the plane at eye level and look at it directly nose on.  Moving only your eyes, look at each wingtip.  If you can see the bottom or top of one wing more than the other, you have a warp that needs correcting.  Ideally you want them even with the center of the wing, but the important thing is that they be equal. Breathe on the wing like you would to fog up a mirror, while twisting it in the desired direction.  Hold it for a few seconds, and then check the result.  Repeat as needed.  Usually only a small change is required. Once you have the plane flying straight and true, launch it with one wing down, and watch as it turns.  It may keep that wing down, or it may level out, or it may continue to drop a wing.  Try it in each direction.  If it drops a wing one way, but levels out the other, you still have a little warp.  I find that most Jetfires get to a point where they will hold a turn one way, but level out the other way. The more bank angle you start with, the tighter the circle.    You'll find that the plane will descend more in a turn if you don't add force to the throw.  Add a little more force and a little more bank angle, and soon you'll have the plane circling back to you.  Add more force with the wings level and it will loop the loop. Here is an important lesson: A turn is really a horizontal loop. There is one difference however.  Take the rudder off the Jetfire, and do a straight launch.  With a little care it will fly fine though it may skate sideways a little.  You can loop it.  Now try your circle.  Didn't work so well, did it?   What happened?  The V shape of the wings is called dihedral.  Anytime the plane tries to fly sideways, dihedral will raise the leading wing.  The vertical tail tries to keep the plane from flying sideways.  In a turn, the plane wants to fall and fly sideways towards the ground.  This raises the low wing and the plane rolls over the top. With the rudder, the amount of sideways flying is reduced.   The right amount of rudder and dihedral will cause the plane to slowly return to wings level.  (If you put a bigger rudder on a Jetfire, you can make it spiral into the ground.)

End of Lesson One

If you've gotten this far, I hope you have had some fun playing with gliders.  After all, this is about fun.  You've learned the parts of a plane, and how it wants to fly.  You have a good basis for launching your first RC sailplane, and you know what to look for on its first flights.  You've learned the basics of trimming. You know that a glider will fly itself - the Jetfire has no radio. It will turn, and glide, and loop the loop and even land itself when it is properly trimmed. What's the next step?  Take all the advice I ever ignored: 1) Don't teach yourself to fly.  (But if you must, do it with a Jetfire and the Sailplane and Soaring Manual.) 2) Join the AMA.  The magazine is great reading and the insurance is nice too. 3) Start with a floater glider like one of these: And of course, never ignore having fun.