These 1st generation R/C helicopters have serious issues. The main one is that the tail rotor speed control is a series of voltage drops (4, I believe), so it is not proportional to the input, and compensating for the main rotor is difficult, if not downright impossible, that's why you can get them to fly at one setting and then change radically if you increase power. This year, they came out with a coaxial design that uses a tail rotor mounted a 90 degrees (same plane as the co-axial rotors) and it gives better control. For a basic helicopter, these work O.K. The next step up are the ones that actually have a squash plate, giving cyclic and collective controls. Now your talking about a real helicopter, (kind've).
