Elios 2 - Troubleshooting


POI images are not saved onto the SD card

If the camera SD card is full, new photos (POIs) cannot be saved. A warning appears when the camera SD card gets full for the first time.



SD card is full, check that you have enough space in the video SD card before flying.



Camera stops recording after several
minutes into a flight.

Cockpit error message:

This occurs mainly when recording in 4K with certain 32GB sd cards (SanDisk Extreme 32GB)

Only use 64 or 128 GB SD cards: Sandisk Extreme micro SDXC UHS-I V30 recommended

Note that E2 is shipped with this 64 GB SD card. Do not swap it with the Payload log SD card, which is 32 GB (The log recorder won't work with SD cards over 32GB).

There is fog on the lens

Condensation may form on the camera lens when the drone is cold and it enters hot, humid air. In some cases the condensation forms on the inner side of the lens, where it cannot be wiped off and it takes longer to disappear.

Pre-heat the drone (in a building or in a car) to prevent condensation.


When condensation forms:

- Wait until it disappears

- Go back to a colder place. Condensation will disappear faster


The camera image preview no longer works
when the drone is in standby for too long. 

RC unit cannot connect to the drone.

Drone transmitter Lights are off.

Leaving the aircraft ON without flying for too long in hot environments might overheat the radio system. The radio system will automatically switch off to avoid permanent damage.

Unplug the drone and let it cool down.


SD Cards

Which card should I use as a camera SD card?

The 4K camera is somewhat sensitive to the SD card used due to the high write data speed.
Therefore, it is crucial that only the recommended SD cards are used.

We recommend using the Sandisk Extreme micro SDXC UHS-I V30 64GB SD card which we also provide with each drone. It has been thoroughly tested and validated at the office and on the field.

Alternatively, the 128GB version of the same series could be used. Sandisk Extreme micro SDXC UHS-I V30 128GB.

32GB SD cards must not be used for the Elios 2 camera as these use the slower SDHC interface. A fast SD card with an SDXC interface is required for 4K recording.

Should I format the camera SD card with exFAT or FAT32? Use the recommended 64GB or alternative 128GB microSD card and format it with exFAT.
Do not use different cards or file systems.

Which card should I use as a LOG SD card?

The 32 GB SD cards provided with the Elios 2 should be used for both the Payload and Avionics logs.
The model is Sandisk Extreme micro SDHC UHS-I V30 32GB SD card. Only SD cards up to 32GB can be used for the data logging.


Radio Link

Drone will not connect to controller

Drone is not paired to Controller, perform pairing procedure.

'Signal too strong' message appears

The drone is too close to the controller during start-up to establish a connection.



One motor does not start after arming.                    

Disarm and try again. If the problem persists then replace the motor.

Drones yaws uncontrollably when pushing
against ceiling or in confined spaces.

Do not push against ceilings, switch to manual throttle/ATTI mode in extremely confined spaces (<600mm diameter).



The drone drifts in large dark open spaces.
The automatic stabilization seems ineffective.

The sensors are less effective in such environments. Switch to the ATTI flight mode (in most cases the drone will do this automatically).

Familiarize yourself with using the ATTI flight mode in a safe environment.

Drone can get stuck in very cluttered or narrow spaces, or if it rolls over into a corner

Use Manual thrust to get it unstuck. Disarm and restart the drone, this resets the motor speeds, and the initial uprighting maneuver is more violent and can help dislodge you.

Drone stabilization won't work properly in environments with very little visual features
(shiny, uniform or very dusty).

Switch to the ATTI flight mode. Plan your flight to pass near features if possible.

Stabilization does not work properly,
even though I am flying close to objects
with plenty of features.

The sensors might be dirty. Remove any dust from the stabilization sensors. These must be cleaned every flight in dusty environments.

Or: the stability sensors might not be paired correctly.

Rebind the stability sensors.

  1. In Cockpit, go to the maintenance page
  2. Click "Rebind sensors"
  3. Look at the blinking LEDs on your drone and follow the sequence to rebind

The green/red navigation LEDs stop working. 

Cockpit error message: CALIBRATE SENSOR

The position of each sensor must be ‘calibrated’ into the drone. Currently, if the drone stays in standby mode for a very long time (more than 30min) It will lose track of the location of each sensor. The LEDs of an ‘unpaired’ sensor will no longer work to indicate this failure.

If this error occurs: Rebind the stability sensors.

  1. In Cockpit, go to the maintenance page
  2. Click "Rebind sensors"
  3. Look at the blinking LEDs on your drone and follow the sequence to rebind



The LOG files will not load properly

ELIOS2 requires Cockpit 2.0 or higher to read the LOG files.

The POIs of another flight will also appear,
and the thermal video might not be correct.

Restart inspector before loading another flight in inspector.



I plugged the battery into the charger, but the light stays green and it will not charge.

The battery has a built-in temperature sensor, and will not accept a charge when it is too hot. Let the battery cool down and re-connect the battery.