what happened to channel 5
guys,i m new to the rc aircraft and rc flight simulator world. my question is that. when i calibrated my dx6i with phoenix 4 last night. i noticed when i moved around the sticks. those bars represented channel 1,2,3,4 and 6 went up and down. but there was absolute no effect on channel 5. was that normal? in the real rc world. which part of the plane is actually controlled by channel 5. thanks.