Takeoff command

I am trying to simulate a drone that will interact with the QGroundControl Unit using the mavlink protocol.

I am trying to make the drone preform a takeoff action,
as a responde to the QGroundControl sending a command long with command numbered 22
the drone responde with a command ack , I also sets its altitude to the last parameter given from the command long and change the costum_mode to ‘poshold’ in the heartbeat command.
but the QGroundControl shows that the drone is still on the ground,

Am I missing a command to make the drone takeoff?