When the helicopter encounters a cross-wind and the tail drifts, a control signal from the gyro computes the drift angle and constantly outputs a control signal that resists the cross-wind. This stops drifting of the tail even in moderate/strong cross-winds. The gyro itself will automatically auto trim to keep the helicopter flying in the same direction ie keep a heading locked. Also when the tail of the helicopter rotates, the servo also rotates in accordance with angle of rotation of the tail. When the tail stops rotating, the servo judges that it has stopped in that position.
A:Delay (Gyro Gain adjustment )
A."+"(clockwise)increase the ability of gyro to balance the helicopter (stable but less active):
B"-" (counterclockwise) decrease the ability of gyro to balance the helicopter (active but less stable)
Attention: When adjusting the gain of Gyro, the gain is differs when applied with different servos or different helicopters. generally speaking, the faster the tail servo responds, the gyro's gain will increase. The faster the helicopter's main rotors rotate; the tail servo's responds will be stronger, therefore, the gain of gyro should be reduced.
B REV/NOR (Normal and reverse switch)
REV Switch: reversing switch for gyro adjust the tail servo's direction.
REV: Reverse motion NOR: Normal motion
Attention: When checking the action direction of Gyro, lift up the helicopter and let the head of the helicopter turn left. If the direction of the tail servo turns is in accordance with the transmitter's stick turns, it indicates that the initialization setting is right. Otherwise, you should switch the Normal and Reverse Switch of gyro.
The wrong setting will cause the helicopter dangerous with high-speed self-rotation when flying. Please double check to make sure that the action direction of the gyro is correct.
C: Limit (Servo range control)
Limit: Adjust the maximal range of tail servo
A. When "+" (clockwise) increase the range of tail servo will increase.
B. When "-" (counterclockwise) decrease the range of tail servo will decrease.
Attention: Adjust the knob to limit the tail servo range within the maximal displacement range of the tail pitch sliding bush when the rocker of the tail servo being moved to both left and right fully, by doing this, the range of tail servo won't exceed the limitation so as to protect the servo and the link lever when flying. On the other hand, don't adjust the servo's range too short to reduce the gyro's performance
D: LED (Status indicator)
A. After connecting the power, the continuous red flashing indicates the procedure intialization.
B. Stable red light indicates that Gyro is locked.
C. Red light going off indicates that Gyro is unlocked
Radio Controlled Helicopters 
