Remote Control Helicopters

27 Apr 2011 - Cliff

ornithopter

About 500 years ago, Leonardo da Vinci dreamed up a fanciful machine called the Ornithopter, which he hoped was capable of vertical flight. It was not until the early 1900s that the dream was realized, and what was then known as the helicopter was flown by Cornu. Sikorsky created the first successful helicopter in the 1940s. What was a whirling mass of thousands of parts has now been miniaturized to a form factor from a tiny remote control helicopter that will fit in the palm of your hand to one or as large as a patio table.

As a kid, I flew model airplanes, and I was always interested in helicopters. There is something interesting about the ability to hover- or even fly backwards. As I got older I got away from the hobby, but to this day I still have a fascination with the intricate machinery, as well as the skill required to fly these miniature aircraft.

What is interesting about these remote control helicopters is the complexity of the flight controls. You have all the same controls as their full sized cousins, such as pitch, yaw and roll. Nose forward and the copter picks up speed in that direction. Nose back and you stop, or even start going backward. By adjusting the thrust of the tail rotor you can change the direction the helicopter is pointing, but not necessarily the way it is flying. You can also roll right or left.

As fascinating as that is, what makes the remote control helicopter such a challenge is that the direction you need to move the sticks changes, depending on the orientation of the helicopter from the pilot. For example, as a real helicopter pilot, if you bank right using the cyclic, you always fly to your right. As with an RC heli, if the tail of the heli is facing you, and you bank right, you go right. However, if the nose of the heli is facing you, the helicopter will slide to the pilot’s left.

Walkera Dragonfly Remote Control Helicopter

The remote controls have a cyclic and collective stick, just like the full size helicopters. The cyclic basically tilts the rotor disk. The collective changes the blade pitch all at once, or makes the helicopter rise and fall. In a full size helicopter the tail rotor is usually controlled by foot pedals, on our remotes we use the collective left/right.

Compounding this issue (and the learning curve), you can do some things with RC helis that you cannot do with a manned helicopter, such as 3D aerobatics, and inverted flight. If you invert the helicopter (done with a roll and the inverting the pitch of the blades), your control orientations change again. Needless to say, learning to fly can be brutal, and most people give up after a few tries or a crashed helicopter.

I am still at it, I’m certainly not an expert but I can at least get a little of the basic maneuvering down. One of the first things you have to learn is how to hover, and tragically that’s one of the most difficult. Hovering is actually flying with minute corrections of left, right, forward and back. And to really throw a wrench in the works, when you first lift off, the ground effect of the rotor wash can make the helicopter unstable. Anyway, when you get it all together the results can be spectacular:

This is Justin Jee. Justin is seven years old. He’s been flying for about 3 years. He holds an inverted hover right at about the 4 minute mark…

Meanwhile I’ll stick with my flight simulator and indoor electric helis- someday I’ll get there. Maybe Justin can send me some tips. 🙂