HOBBYEAGLE A3 Aeroplane Flight Controller Stabilizer System 6-axle Gyro for RC Drone Airplane Fixed-Wing Copter Standard Wing Type, Delta-Wing and v-Tail. Separated Gain Adjustment for Each Flight Mode. Please Confirm The 13-Bit Unique Product Series Number (s/n) On The Bar Code Label When Purchasing. This Number Can Be Verified At Our Website and It Is Also Required In The After-Sale Service, Please Keep It Securely! Before Power On, Put The Aileron, Elevator and Rudder Sticks In The Middle Position. The Controller Needs To Perform Self-Calibration and Stick Centering After You Plugging The Battery The Led Will Keep Blinking Blue Rapidly For About 3 Seconds While Calibrating, Just Don't Move The Plane And The Sticks Until The Initialization Is Done.