# Land Mode (Fixed-Wing)

The Land flight mode causes the vehicle to descend at the position where the mode was engaged, following a circular path until touchdown. After landing, vehicles will disarm after a short timeout (by default).

注意

Fixed-wing land mode should only be used in an emergency! The vehicle will descend around the current location irrespective of the suitability of the underlying terrain, and touch down while following a circular flight path.

Where possible, instead use Return mode with a predefined Fixed-wing mission landing.

注解

  • Mode is automatic - no user intervention is required to control the vehicle.
  • Mode requires at least a valid local position estimate (does not require a global position).
    • Flying vehicles can't switch to this mode without valid local position.
    • Flying vehicles will failsafe if they lose the position estimate.
  • Mode prevents arming (vehicle must be armed when switching to this mode).
  • RC control switches can be used to change flight modes on any vehicle.
  • RC stick movement is ignored.
  • The mode can be triggered using the MAV_CMD_NAV_LAND (opens new window) MAVLink command, or by explicitly switching to Land mode.

# Technical Summary

Land mode causes the vehicle follow a descending circular path (corkscrew) until touchdown.

When the mode is engaged, the vehicle starts to loiter around the current vehicle position with loiter radius NAV_LOITER_RAD and begins to descend with a constant descent speed. The descent speed is calculated using FW_LND_ANG and the set landing airspeed FW_LND_AIRSPD. The vehicle will flare if configured to do so (see Flaring), and otherwise proceed circling with the constant descent rate until landing is detected.

Manual nudging and automatic land abort are not available in land mode.

# Parameters

Land mode behaviour can be configured using the parameters below.

Parameter Description
NAV_LOITER_RAD The loiter radius that the controller tracks for the whole landing sequence.
FW_LND_ANG The flight path angle setpoint.
FW_LND_AIRSPD The airspeed setpoint.

# See Also