Pymavlink DISARM command

Hello, I am trying to arm my SITL drone using command from that link
http://discuss.bluerobotics.com/t/sending-mavproxy-messages-from-a-python-program/1515/2 I am using MAVLink in 2.0 version.

my code looks like 
autopilot.mav.command_long_send(
1, # autopilot system id
1, # autopilot component id
400, # command id, ARM/DISARM
0, # confirmation
0.0, # disarm!
0.0,0.0,0.0,0.0,0.0,0.0, # unused parameters for this command,
 force_mavlink1=False
)

According to file /usr/local/lib/python2.7/dist-packages/pymavlink/dialects/v20/common.py
i should use float as a parameter.

        Send a command with up to seven parameters to the MAV

        target_system             : System which should execute the command (uint8_t)
        target_component          : Component which should execute the command, 0 for all components (uint8_t)
        command                   : Command ID, as defined by MAV_CMD enum. (uint16_t)
        confirmation              : 0: First transmission of this command. 1-255: Confirmation transmissions (e.g. for kill command) (uint8_t)
        param1                    : Parameter 1, as defined by MAV_CMD enum. (float)
        param2                    : Parameter 2, as defined by MAV_CMD enum. (float)
        param3                    : Parameter 3, as defined by MAV_CMD enum. (float)
        param4                    : Parameter 4, as defined by MAV_CMD enum. (float)
        param5                    : Parameter 5, as defined by MAV_CMD enum. (float)
        param6                    : Parameter 6, as defined by MAV_CMD enum. (float)
        param7                    : Parameter 7, as defined by MAV_CMD enum. (float)

Unfortunately the result which i can see in SITL command line is
Got MAVLink msg: COMMAND_ACK {command : 400, result : 3}
Which mean that there is some mistakes

Thanks for any help

Francisco Ferreira send me explanation. I tried to use disarm as a emergency motor stop.

According to https://github.com/ArduPilot/ardupilot/blob/master/ArduCopter/GCS_Mavlink.cpp#L1104 i should use extra param2.

Simple emergency landing looks like
#EMERGENCY LANDING
autopilot.mav.command_long_send(
1, #1# autopilot system id
1, #1# autopilot component id
400, # command id, ARM/DISARM
0, # confirmation
0.0, # disarm!
21196.0,
0.0,0.0,0.0,0.0,0.0, # unused parameters for this command,
force_mavlink1=False
)