Hooking an arduino up to a quadcopter controller

Hi all, I'm relatively new to Arduino and recently I've run into the issues just figuring out if something is possible. I attempted to search around for it for quite a while but because of the vagueness of the subject or the exactness depending on how you look at it, I haven't been able to find out anything. In essence, i have a small quad copter, and id would like to control is using an arduino, so i can try and create an autopilot for it. The controller the quad copter comes with has two thumbsticks and buttons for trim. What im curious about is if i took the controller apart, found the inputs on the controller that read when the joystick is moved and such, and instead wired those into the arduino, would such a thing work? Is the a feasible thing to do or is there issues that would arise by doing so?

Yes, you can probably feed voltages into the transmitter in place of the joysticks. The first step would be to measure the output voltage of each control axis. The six PWM outputs can be used as analog outputs by using a resistor and capacitor to smooth the pulses.

Alright, seems simple enough. Thank you.