If the drone loses connection to the remote control, this does not necessarily mean that it will fall from the sky. Depending on its configuration, it can hover in place, return to its starting point, or attempt to land automatically. But if the aircraft also loses access to reliable navigation data, the situation can become significantly more complicated.
What happens next depends on which connection is down, which flight control systems are still available, and how the drone was programmed to respond.
Not all signal losses are equal
Most consumer drones rely on multiple communication and navigation systems working together. The most obvious is the command and control link between the aircraft and its remote control. It contains the pilot’s instructions, such as changes in direction, altitude and speed.
Many drones also transmit a live video feed and flight telemetry to the controller. These connections can experience glitches or dropouts independent of the control connection, meaning a pilot can sometimes lose camera feed while maintaining control of the aircraft.
Navigation is another matter. Drones commonly use global navigation satellite systems (GNSS), including GPS, as well as integrated sensors such as compasses, accelerometers and gyroscopes. These help the air traffic controller determine the aircraft’s position, orientation and movement.
Loss of controller connection does not automatically mean loss of GPS navigation. Likewise, a drone may lose reliable GPS or compass information while remaining connected to its pilot.
What does a drone do when the connection is lost?
Many modern drones have a fail-safe feature called Return to Home (RTH). If command connection is lost for a configured period of time, the aircraft can use its stored homepoint coordinates and navigation systems to fly back to its takeoff location.
Depending on the model and settings, the drone may first climb to a predetermined altitude to clear obstacles before following its return route. It can then descend and land automatically.
However, RTH is not the only possible response. Some drones can be configured to hover at their current position or land anywhere if connection is lost. The chosen behavior often depends on the aircraft, its firmware and the pilot’s settings.
For example, DJI drones offer configurable signal loss responses on supported models. Open-source flight control software like ArduPilot also offers several fail-safe actions, including Return to Launch, SmartRTL, and Land.
These protections are useful, but they are not guarantees. RTH requires that the drone has sufficient battery power, a valid home point, and the navigation information necessary to track its route. Obstacles, wind, sensor errors or other system failures can prevent the maneuver from being carried out safely.
What happens if the drone loses its GPS?
Loss of GPS or other navigation data can be more challenging as the aircraft may no longer know its exact position.
Some multirotor drones enter a flight mode commonly known as Attitude Mode (ATTI). In this mode, onboard sensors can help stabilize the aircraft’s orientation and maintain altitude, but it no longer automatically maintains its position using GPS.
This allows the wind to push the drone away from its original location. The pilot must perform compensation manually via the controller, which can be difficult if the aircraft is far away or difficult to see.
A particularly dangerous situation arises when a drone loses both its command connection and the navigation data needed for RTH. It may not be able to receive instructions from the pilot or determine how to return to its starting point.
Real incidents show why failsafes are not foolproof
Two investigations by the UK’s Air Accidents Investigation Branch (AAIB) illustrate how navigation problems can lead to serious incidents.
In December 2019, a GPS compass error occurred while surveying a construction site with the DJI Matrice M600 Pro. The aircraft transitioned from automated flight to ATTI mode, requiring manual control. Their pilot repeatedly attempted to activate RTH, but the drone continued to drift with the wind. It eventually hit the roof of a house before falling into the property’s garden. Investigators determined that the aircraft had lost reliable heading information, preventing it from completing the return maneuver.
In another incident in November 2021, a DJI Phantom 4 Pro encountered magnetic interference shortly after takeoff in Rugby, England. The pilot received warnings that the aircraft had lost its heading reference and could no longer operate in normal GPS-assisted mode. The command connection then failed and the drone hovered about 630 meters above a populated area before landing in a tree.
Both incidents show that automated recovery depends on more than just enabling failover.
Can pilots prevent a flight?
Pilots can reduce risk by checking GPS reception and compass alerts before takeoff, selecting an appropriate RTH altitude, and ensuring homepoint has been recorded correctly. You should also monitor battery levels, weather conditions, and possible sources of electromagnetic interference.
Equally important is that pilots understand how their specific aircraft will behave if navigation or communications systems fail. Practicing manual flight and emergency procedures can make a significant difference when automated flight modes are no longer available.
A drone’s ability to recover from signal loss depends on the systems remaining operational. RTH and other failsafes can help an aircraft deal with routine communications interruptions, but they cannot compensate for every combination of sensor errors, interference and environmental conditions.
