The motors are disarmed, and how to see why

The copter has disarmed: the motors are stopped until it is armed again. In 4.6 and 4.7 a real flight controller sends no text for this (“Disarming motors” comes from the simulator and older firmware). The log has an ARM message with ArmState 0 and the event DISARMED (EV 11); its Method field says why: 0 the yaw stick, 1 the ground station, 2 a switch, 12 a crash was detected, 13 it landed at the end of Land, RTL or Auto, 17 it stood on the ground with low throttle for DISARM_DELAY seconds, and 7, 16 or 18 a battery, radio or ground-station failsafe while on the ground.

What to do, most likely first

1. It disarmed by itself a few seconds after arming: Method 17, the DISARM_DELAY timer (10 s by default).

   FixTake off sooner after arming. The timer runs only while the copter is on the ground with the throttle low; it cannot disarm in the air.

2. It disarmed in a crash or a hard landing: Method 12, with “Crash: Disarming…” just before.

   FixRead the explanation of that message: the crash check stops the motors when the copter is far from the attitude it wants and no longer accelerating.

3. A failsafe disarmed it: Method 16 (radio), 7 (battery) or 18 (ground station).

   FixA failsafe disarms at once when the copter is landed. In Stabilize and Acro it also does so when the throttle stick is at zero, even in the air: keep some throttle on in those modes. The Failsafe Explainer shows each case for your parameters.

4. The ground station's disarm command was refused: the copter does not count itself as landed.

   FixLand and lower the throttle fully, or use the transmitter. A forced disarm from the ground station stops the motors in the air too: use it only to prevent harm.

Disarming with the yaw stick (fully left, throttle down) needs ARMING_RUDDER 2 and, in the modes that hold height, a copter that has landed. It takes 2 seconds in 4.6 and 3 seconds in 4.7.

Parameters to look at

Where to do it:Setup & Tuning GuideSetup & Tuning Guide