2. Fixed Pitch Or Collective Pitch

We thought we'd had it all worked out when learned that there is a further subclass of helicopter: Fixed Pitch or Collective Pitch. Fixed Pitch helicopters have a main rotor that never changes its angle. In a fixed pitch helicopter, the only thing that determines whether the helicopter rises, hovers or falls is the throttle. More throttle makes the helicopter rise, less throttle makes it fall. Simple.

A Collective Pitch helicopter is markedly different. The main rotor turns at a constant speed whether the helicopter is rising or falling. What determines the helicopter's up and down movements is the pitch of the main rotor. If the pilot wants the helicopter to rise, he or she changes the pitch (or angle) of the rotors to push more air downward. If the pilot wants the helicopter to fall, they change the pitch of the rotors to push less air.

The main advantage of a Collective Pitch RC helicopter is the ability to fly upside down. This ability is also called "3d capability" in the RC helicopter world. This is very difficult, but an experienced pilot can fly a Collective Pitch helicopter upside down by reversing the pitch of the main rotors at the right time to force air toward the top of the helicopter instead of below it.

On a Collective Pitch Rotor, the angle of the individual blades can be increased or decreased.

The main disadvantage of a Collective Pitch helicopter is how the machinery is much more complex than that of a Fixed Pitch configuration, and is therefore more susceptible to damage - the kind of damage that newbie pilots are bound to cause. With this in mind, and no illusions that we would be good enough pilots to consider flying upside-down in the near future, we made our choice.

What we wanted was a fixed-pitch RC helicopter in the standard Sikorsky configuration.