PrecisionFlight Emergency Functions

Within the PrecisionFlight app there are several emergency functions that can be used throughout your mission (Highlighted in Red below). 



Go Home: 

Tap this button and slide down to bring the drone to land at the takeoff location.


Land Now:

Tap this button and slide to land the drone immediately right where it is.


Pause Mission:

Tap this button and slide to make the drone hover at its exact location during a flight. This feature will allow you to continue on the mission when you are ready. 




DJI Hardware Emergency Functions

Return To Home Button (RTH): 

This button is on your RC controller to the left of the power button. To activate press and hold until it begins beeping and flashing the light beneath the button. Much like the "Go Home" feature of the app it will return to the home position and begin the landing sequence. 


Mode Switch:

DJI devices have several modes- Position Hold (P), Sport Mode (S), and Altitude Holde (A). When flying in the app your drone is in P mode which reads the GPS signal to establish its position. If GPS loss if experienced switching to A mode is the best course of action. 


Combination Stick Commands (CSC):

This is typically your last resort for emergency functions. When this stick command is done the drone will kill the motors and fall from the sky. 




Emergency Situations

Below we have reviewed a theoretical plan of action behind the most common emergency situations that could be experienced. This is not to be used as a standard work procdeure in these situations but as an example of how the emergency functions mentioned above can be used. It is always a good idea to have two operators in the field. The pilot is operating manning the controls and application throughout the flight while the Visual Observer (VO) monitors the aircraft and airspace. 



Low Signal Warning: 

    Situation:

  • Pilot observes audible and/or visual warning in the PrecisionFlight app when the signal strength is below 30%.


Things to keep in mind:

  • Your link signal is low. Any operation that you command with the app or RC might need to be attempted multiple times or could be delayed due to the weak signal.
  • If you transition from a low signal warning to loss of communication refer to the Lost Communication emergency procedures section of this document



#
Pilot Action
VO Action
1
Cycle the mode switch from P mode to A mode and back to P mode
Visually confirm if the drone holds position
2
Check that RC antennas are pointed up and out towards the UAV
Keep constant line of sight with the UAV
3
Ensure distance from home reading in the app is within operational range (5km)
Monitor for potential obstructions between the UAV and RC that could cause interference
4
Use the Return To Home button on the RC to land the UAV
Visually confirm if the UAV has initiated Return to Home.
5
Retrieve the UAV
X




Lost Communication

    Situation: 

  • Pilot/VO observes low signal warnings from the InFlight application followed by complete loss of connection. The UAV looks frozen in place on the map of the InFlight screen.


    Things to keep in mind:

  • The UAV is programmed to return home after 10 seconds of full communication loss.
  • Immediately check for GPS signal in the application. If this is weak follow GPS Loss section of this document.
  • Check RC indicator light. If GREEN follow table A if RED follow table B    


A.

Pilot Action
VO Action
If transmitter connection LED is GREEN
1
Cycle the mode switch from P mode to A mode and back to P mode
Visually confirm if the drone holds position
2
Try to re-connect the drone to PrecisionFlight app
Maintain line of sight with the UAV
3
Use Go Home emergency button on the app and slide down to initiate Return to Home
Visually confirm if the drone has initiated Return to Home
4
If the drone does not respond to above action press and hold the Return Home button on the RC
Visually confirm if the drone has initiated Return to Home
5
Safely retrieve the Drone and Sensor
X


B.
Pilot Action
VO Action
If transmitter connection LED is RED
1
Cycle the mode switch from P mode to A mode and back to P mode
Visually confirm if the drone holds position
2
Restart the RC and check if you have control over the aircraft
Keep constant line of sight with the Drone
If the transmitter LED turns GREEN jump back to scenario A
3
Press and hold the Return Home button on the transmitter to bring the UAV in for landing
Visually confirm if the drone has initiated Return to Home
4
Standby for a few seconds (>3 seconds) and observe if the drone will trigger automatic fail-safe and return home.
Keep constant line of sight with the drone and watch out for obstacles
If the UAV does not return home and indicator is still red repeat from step 1 of this table.

5
Monitor landing and safely retrieve UAV when ready
X



UAV off Course (Within Line of Sight)

    Situation:

  • Pilot notices the UAV is not following expected course within line of sight.


    Things to keep in mind:

  • The expected course from takeoff to way point 1 is a straight line once survey altitude is met. 
  • The expected course from final way point to landing is straight line at survey altitude.

    

#
Pilot Action
VO Action
1
Monitor GPS signal in the PrecisionFlight app
Keep constant line of sight with the Drone
If GPS is good follow the steps below. If it is not follow the steps within (V) GPS Loss Emergency procedures

2
Cycle the mode switch from P mode to A mode and back to P mode
Visually confirm if the drone holds position
3
Press and hold the Return Home button on the transmitter to bring the UAV home for landing
Visually confirm if the drone has initiated Return to Home
4
Safely retrieve the Drone and Sensor
X


    


Flyaway (Beyond Line of Sight)

    Situation:

  •     UAV has flown away to an unknown location beyond line of sight. 


    Things to keep in mind:

  • As soon as you lose sight monitor communication percentage and the indicator light on the RC. If Red or low communication percentage refer to Low Communication Signal or Lost Communication emergency procedures.


#
Pilot Action
VO Action
1
Talk with VO and monitor the PrecisionFlight app for the last known direction of the UAV
Talk with the pilot to search the most probable direction of the UAV
2
Toggle the mode switch to P (Position Hold)
Visually confirm if the drone holds position
3
Press and hold the Return Home button on the transmitter to bring the UAV home for landing.
Visually confirm if the drone has initiated Return to Home
If UAV does not return home
4
Quickly open DJIGo and connect to the UAV
Monitor horizon for sight of the UAV
5
Access camera view to help find the UAV. Fly and land the UAV using the camera view to your location if possible
Monitor horizon for sight of the UAV
If you are uncomfortable or unable to get your bearings using the steps above continue to steps below
6
Open the Flight Logs and find out the coordinates of he Drones las know location
Monitor Airspace and try to reestablish visual contact
7
Initiate a search around the last known location until recovered
Assist the pilot to locate the Drone




Low GPS Signal or GPS Loss

    Situation: 

  • Pilot/VO observes low or lost GPS signal on the ground control station.


    Things to keep in mind:

  • GPS loss is one of the most difficult emergencies to overcome. The UAV does not know where it is in space so it is up to you to get it back using manual RC.
  • Another symptom of GPS loss would be the UAV not following the expected route. Action should be taken immediately if any strange behavior is suspected.


#
Pilot Action
VO Action
Drone is within Line of Sight
1
Toggle the mode switch to A (Altitude)
Maintain visual line of sight with the UAV
2
Fly for landing using manual controls and visual line of sight on the UAV
X
Drone is beyond Line of Sight
1
Toggle the mode switch to A (Altitude)
Maintain visual line of sight with the UAV
2
Quickly open DJIGo and connect to the UAV
Monitor horizon for sight of the UAV
3
Access camera view to help find the UAV. Fly and land the UAV using the camera view to your location if possible
Monitor horizon for sigt of the UAV