The motors are armed

The copter has armed: every check passed, home was moved to where it stands (unless you fixed it by hand), and after a 2-second delay the motors turn at their arming speed, MOT_SPIN_ARM. In 4.6 and 4.7 a real flight controller sends no text for this: “Arming motors” comes only from the simulator and from older firmware. In a log, look for the ARM message with ArmState 1 and the event ARMED (EV 10). Its Method field says who armed it: 0 the yaw stick, 1 the ground station, 2 a switch, 4 a script. Forced 1 means the checks were skipped.

Armed means the propellers can turn at any moment. Hands, faces and cables stay clear until it is disarmed. Holding the yaw stick fully right with the throttle down arms after 2 seconds in 4.6 and after 3 seconds in 4.7.

Parameters to look at

Where to do it:Setup & Tuning Guide