fsteyer

please indulge my ignorant question:
why would you need a 9 channel transmitter to fly a helicopter?
thank you

VinceHerman

You don't. 4 channels will fly a typical fixed pitch helicopter. 5 or 6 are most often used for a typical collective pitch heli.
Where the 9 channel transmitter comes in is in the advanced mixing and programming capabilities that a higher end transmitter has.
Being able to support various swash plate configurations, CCPM mixing, throttle and pitch curves, revo mixing, all of these let you do more with the RC heli hobby.
Other features like end point adjustment, model memory, dual rates, exponential and such are added bonuses.
Additional channels make adding retracts or onboard cameras doable.

The common recomendation is to get all the transmitter you can afford.

BarracudaHockey

My Feedback: (11)

For example.

Aileron
Elevator (well the equivelents)
Rudder
Throttle
Collective Pitch
Gyro
Governor

The 9C are only really 9 channels with a PCM reciever but there's 7 without retracts or lights that you might put on a scale ship, of course a scaler probably won't have a governor.

Like Vince said, its mostly for the programming and mixing and such.

-pkh-

My Feedback: (2)

Here's the common channel setup for a CP heli...

1) Left-Right Cyclic Pitch
2) Fore-Aft Cyclic Pitch
3) Throttle
4) Tail Pitch (goes to gyro, tail servo plugs into gyro)
5) Gyro Gain (for remote gyro gain adjustment if you have it)
6) Collective Pitch

So 1-4 will due for a FP heli, and you really need ch 6 for a CP heli, or the ability to make the 5th channel collective pitch if you only have a 5ch RX.

As mentioned above, the other major consideration is that the radio must have the proper mixing functions for the helis you want to fly... you need to be able to set separate throttle & pitch curves, and you may need cyclic collective mixing functions depending on the swash type your heli uses...

fsteyer

thanks for all the great answers.