i just got a used walkera 36 and this is my first chopper,i didnt get much for instructions on it,so i charged the battery and tried to fly it, but when i give it power the brushless motor makes a squeching sound and the blades start to turn and then they stop,i dunno if the motor is going bad or if its the battery?,also any tips on flying or any info would be great,like i said im totally new to these