High pitch squeel

[btorphoto]

Greetings, I am a new phantom flier,Phantom 2,gopro 3+ and z gimbal.
I have notice a high pitched squeel when its above me,
Is this normal?
Thanks in advance...

 

[reALIGNed]

You can begin by checking for a bad motor bearing. One motor at a time with the props removed ( for safety). Hook it up to the assistant and perform the motor test and listen carefully to a change in sound on each motor.