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