Fixed pitch vs. Collective pitch

If you are new to R/C helicopters you are probably wondering what the heck is fixed and collective pitch anyways?
The pitch in R/C helicopters refers to the angle of the blade with respect to the horizontal plane.
A heli with a fixed pitch has main rotor blades that remain in a fixed position.
Fixed pitch helis are well suited for beginners because there is one less thing to control, making them that much easier to fly.
With fixed pitch helicopters the amount of lift is dependent only on rotor speed and not on the angle or pitch of the blades.




Increased rotor speeds mean there will be more lift, and the heli will rise. Lower motor speeds mean less lift and the helicopter comes down. The newer, more advanced models of helis incorporate a collective pitch.

The main rotor blades can rotate to different angles to change the lift being applied to the chopper. Collective pitch is controlled by the throttle through automatic mixing.

The pitch of each blade changes collectively to create the desired movement of the heli.

Here are some major differences between fixed and collective pitches to give you a better idea of the two.
Differences between fixed and collective pitch
Fixed Pitch
Fixed pitch is easier to build and set up.
It has fewer moving parts.
It is less expensive.
It is slightly easier to fly than collective pitch.
You can only hover indoors and outdoors and fly forward.
Cheaper to repair in case of a crash.
If the engine quits at an altitude the chopper becomes a dead weight because there is virtually no auto-rotation.
Collective Pitch
It is harder to set up because there are more moving parts.
It is more expensive than fixed pitch.
It is harder to fly than fixed pitch.
It is a R/C pilot's delight! You can fly any way you want to indoors and outdoors.
The collective pitch can do fast forward flights, loops, rolls, stall turns, inverted flying, in place flips, and pretty much anything the R/C pilot wants it to do.
Takes more time and money to repair in case of a crash.
If a chopper's engine quits in flight it is still possible to glide the chopper down safely at a low or negative collective pitch setting ; thanks to auto-rotation.
All in all, it seems that the fixed pitch is a good idea for people just starting out. Once you master the fixed pitch helis, you can upgrade to collective pitch and really start doing some crazy stunts!