Flying backward
Operator action: LAND
If the vehicle starts flying backward with increasing speed it is likely to have the pusher propeller mounted in
the wrong direction. The transition should be aborted and the pusher motor should be inspected.
High current slow forward flight
Operator action: RTL
If the vehicle is moving horizontally in the direction of the first waypoint at low speed, with the quadcopter
motors still engaged after 15 seconds, and the current draw remains above 30 Amperes, it is likely that the
mission did not issue a VTOL TAKEOFF command but a TAKEOFF command. The vehicle will attempt to
complete the mission in quadcopter mode. If this was not intended, RTL should be initiated by the operator.
Note: The DeltaQuad can activate its pusher motor in quadcopter mode too. The spinning of the pusher
motor is no indication that the vehicle is attempting fixed wing flight.
During Fixed Wing flight
Abort error displayed due to loss of altitude or maximum bank angle
Operator action: LAND
This error is displayed on the Ground Control Station when the vehicle has activated the failsafe system.
The UAV must be landed as soon as possible. Do not attempt to complete the automatic return sequence if
the vehicle is higher than 100m or further than 800m from the home position. If the battery is lower than 35%
it should always be landed. Use the map to locate a safe area to land the UAV and direct the UAV to this
location. Then press the LAND button to land immediately.
After such an event the cause must be determined before a new flight is attempted. Please contact Vertical
Technologies support for assistance in analyzing the cause of the failsafe event.
Excessive altitude loss
Operator action: Return or LAND
During and shortly after transition, the vehicle may lose some altitude, this is generally not more than 5
meters. In extreme cases (high payload, strong wind). This can be up to 8 meters. The vehicle should
recover from this loss quickly, regain and maintain altitude. Some altitude gain or loss may occur when
banking (changing direction). This should not exceed 5 meters.
If the vehicle does not maintain altitude, or if the altitude error exceeds 10m and the vehicle does not recover
from this altitude error an RTL should be commanded. If the vehicle does not adequately perform the RTL
procedure (continues to lose altitude or fails to navigate back) a LAND instruction should be given. After a
LAND instruction is given, and the vehicle is performing a landing in quadcopter mode, the RTL instruction
can be given again to have the vehicle return in quadcopter mode. This should only be attempted when the
vehicle is less than 1km from the takeoff site and more than 50% of the battery capacity is available.
The reason this can occur could be related to weight, balance or a problem with the servos or pusher drive.
A thorough inspection of the vehicle is required. If the problem can not be found and resolved you should
contact Vertical Technologies support.
Failure to track mission path
Operator action: Return or LAND
During the transition the vehicle does not fly in the direction expected:
When the transition phase completes, the vehicle should fly towards its takeoff location or first waypoint. If
