Troubling arming with MAVLink

MAVLink
1

I am building a GCS application on Android and I am using the dronefleet library to create and parse MAVLink messages.

I am having some trouble arming using the application. I am using the command int message-> MAV_CMD_COMPONENT_ARM_DISARM.

This is the serial message I am sending:

[254, 35, 12, 255, 0, 144, 0, 0, 128, 63, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 144, 1, 0, 0, 0, 0, 0, 18, 3]

The FC arms when I use an RC transmitter to arm it, so I know it is not failing any safety checks.

Questions:

  1. How do I arm using MAVLink messages?
  2. Does the FC send an acknowledgement or an error of receiving MAVLink messages? Is it one of the common.xml messages?