| Coaxial helicopter is one of the more popular | | | | each other results in the extraordinary |
| images that come to mind when people think | | | | stability and hovering ability. Because |
| about electric RC helicopters. And for good | | | | hovering is one of the main components of a |
| reasons too; these double-bladed helicopters | | | | helicopter's flight, "easier to hover" is |
| is accredited with bringing hordes of new | | | | almost synonymous to "easier to fly". |
| enthusiast into the world of RC aviation. | | | | Controlling the yaw in this setup becomes |
| Their popularity stems from their unequivocal | | | | only a matter of slowing or speeding up one |
| stability in the air - which makes them | | | | of the two rotors. Another merit that comes |
| relatively easier to master when compared to | | | | almost as a bonus is that theoretically, |
| their single rotor counter part. They are | | | | these helicopters do not require a gyro - |
| also predictable enough to be flown within | | | | which means that much less tinkering and |
| the compounds of one's home, securing its | | | | setting up is needed. |
| spot as one of the most loved indoor fliers. | | | | |
| Being able to fly right out of the box | | | | Although very widely praised, coaxial |
| because they are sold as RTF (Ready to Fly) | | | | helicopters are not without faults. The first |
| kits adds to their appeal. | | | | one stems from the fact that in order to fly, |
| | | | the speed of the two rotor blades must be |
| So where did such stability come from? To | | | | equal. In fact, these helicopters are so |
| answer that, the first step lies in | | | | dependent on the synchronicity of its blades |
| understanding how helicopters work. A | | | | that even the slightest deviation is |
| single-rotor helicopter generates lift when | | | | detrimental. So much so that these |
| their rotor rotates. As the main rotor turns, | | | | helicopters will just spin wildly on the |
| another force will also be generated - known | | | | ground, never to lift off. Their two motors |
| as torque, which will in turn cause the | | | | simply have to always be in their most |
| entire fuselage to turn in the opposite | | | | pristine state. Also, the stability of these |
| direction. Since the days when helicopters | | | | helicopters comes at the price of sacrificed |
| were in their nascent stage, their pioneers | | | | maneuverability; they are notoriously slow |
| have learnt to counter this effect by | | | | and unresponsive. Nevertheless, perhaps the |
| including another smaller perpendicular rotor | | | | utmost annoyance comes when the two blades |
| in the tail. This rotor counters the any | | | | bite into each other in mid air when most |
| rotation generated by the torque as well as | | | | extreme cyclic controls are applied. |
| provides pilots a mean to control the | | | | |
| direction in which the helicopter's nose is | | | | All in all, coaxial helicopters are here to |
| pointing at, more technically known as the | | | | stay. They have become the favorite |
| yaw. To control the yaw, the pilot simply | | | | beginners' RC helicopter. At the same time, |
| changes the pitch (or the angle) of the tail | | | | many experienced pilot enjoy a flight or two |
| rotor. | | | | of easy indoor flying with these helicopters |
| | | | once in a while. |
| Coaxial helicopters, on the other hand, | | | | |
| eliminate the need of a tail rotor | | | | Note: Although these coaxial helicopters are |
| completely. This is due to the fact that | | | | "relatively" easier to fly than their |
| these fliers have two rotors, one on top of | | | | conventional counterparts, they still require |
| the other, rotating in opposite directions. | | | | hours of practice. Also, their fast rotating |
| In effect, the torque generated by each rotor | | | | blade can cause just as much injury as bigger |
| cancels out one another. When such feat is | | | | model helicopters. Therefore, never treat |
| coupled with two rotors' lift complementing | | | | them like toys. |