# Mission Mode (VTOL)
Mission mode causes the vehicle to execute a predefined autonomous mission (flight plan) that has been uploaded to the flight controller. The mission is typically created and uploaded with a Ground Control Station (GCS) application like QGroundControl (opens new window) (QGC).
VTOL vehicles follow the behavior and parameters of fixed-wing when in FW mode, and of multicopter when in MC mode. For more information see the specific docs for each mode:
The following sections outline mission mode behaviour that is VTOL specificL.
# Mission Commands
The following VTOL-specific commands are as defined in the MAVLink specification.
- MAV_CMD_NAV_VTOL_TAKEOFF (opens new window)
MAV_CMD_NAV_VTOL_TAKEOFF.param2(transition heading) is ignored. Instead the heading to the next waypoint is used for the transition heading.
- MAV_CMD_NAV_VTOL_LAND (opens new window)
- MAV_CMD_DO_VTOL_TRANSITION (opens new window)
Otherwise PX4 generally "accepts" the mission commands for fixed wing or multicopter when in the respective modes.
In fixed-wing mode there are the following exceptions:
- MAV_CMD_NAV_LAND (opens new window) is transformed into MAV_CMD_NAV_VTOL_LAND (opens new window) unless NAV_FORCE_VT is set to
- MAV_CMD_NAV_TAKEOFF (opens new window) is not supported.
# Mission Takeoff
Plan a VTOL mission takeoff by adding a
VTOL Takeoff mission item to the map.
During mission execution the vehicle will ascend vertically to the minimum takeoff altitude defined in the MIS_TAKEOFF_ALT parameter, then transition to fixed-wing mode with the heading defined in the mission item. After transitioning the vehicle heads towards the 3D position defined in the mission item.
A VTOL mission requires a
VTOL Takeoff mission item (
MAV_CMD_NAV_VTOL_TAKEOFF) to takeoff (or a
MAV_CMD_NAV_TAKEOFF when the vehicle is in MC mode); if however the vehicle is already flying when the mission is started the takeoff item will be treated as a normal waypoint.