Aircraft Disconnected Mid-Flight

[Ilmis]

Hello everyone!

Last week I was shooting video with Phantom 4 Pro near a construction yard.

After 4 minutes of flying (height 128m (420 ft), distance 82m (270 ft)) I lost the video link and then the green ”In Flight (GPS)” status in DJI GO 4.0 -App changed to red with a text ”Aircraft Disconnected”.

There was a crane pretty close at the time, and the aircraft status changed couple times between ”In flight (GPS)” and ”Aircraft Disconnected”. The Phantom wasn’t too close to the crane and there were nothing between me and the drone. I pressed the RTH button and the drone came back normally and when the drone was closer I cancelled auto landing and I landed manually. Really scary…

What do you think, could cranes cause problems like this? The usb cable was ok.

The flight log can be found here:
DJI Flight Log Viewer - PhantomHelp.com

Yesterday I made a range test with my friend: I was standing still with the transmitter and my friend was walking away from me with the Phantom (without props). We had a phone connection all the time. There were only 190m (623 ft) between me and the drone when the text ”Aircraft Disconnected” appeared and the small led in transmitter turned red. There were a lot of trees and a power line between me and the drone. At that moment the application showed that I had still RC connection (the radio symbol on right corner) but I couldn’t control the gimbal or start motors. Why? Although there were a lot of stuff between me and the drone, RC-connection shouldn’t lose in 190m (623 ft), right?

What does ”Aircraft Disconnected” actually mean? Can there still be RC connection between the drone and transmitter?

Any help appreciated!

Best regards,
Ilmis

 

[BigAl07]

Hello and welcome to the forum.

Aircraft Disconnected could mean loss of signal to/from the aircraft or it could be merely loss of connection to your viewing device. I had a low quality USB cable and it would occasionally give this message in flight. I would "jiggle" the connector and it would reconnect. The whole time I still had CONTROL of the aircraft but the tablet wasn't connected.

If the LED on the Tx turns red then you do NOT have connection to the aircraft. In my instance above the LED remained GREEN the whole time.

 

[Fly Dawg]

What does ”Aircraft Disconnected” actually mean? Can there still be RC connection between the drone and transmitter?

That is basically a "Generic" Downlink Lost message. You will still have full control, just no video feed or telemetry. If this had been full signal loss, RTH would have initiated in approximately 2 seconds. And you may or may not see a "Signal Lost" message. As BigAl mentioned use the RC status light for confirmation.

 

[Ilmis]

Thank you for your answers!

Today I did a range test without props again. There was only 205m (672ft) between me and the drone when the led turned red and "Aircraft Disconnected" appeared. I have flown RC planes for 10 years and 206m RC range feels a really short distance to lose RC although the drone wasn't LOS at the moment.

I think it's weird that the app shows that there is RC connection, but the led is red... What do you think? (in the below picture)

 

[monki77]

Is your transceiver wifi set to 1 channel instead of auto? Is your video link set to high quality instead of auto? Are your transceiver antennas pointing at the aircraft instead of being perpendicular?

 

[Ilmis]

Is your transceiver wifi set to 1 channel instead of auto? Is your video link set to high quality instead of auto? Are your transceiver antennas pointing at the aircraft instead of being perpendicular?

Actually for some reason I can't change channel mode from Auto to Custom in the HD menu.

Antennas are pointing at the AC like the manual advises.

I think I have to do the range check in a different place. I also had some issues with a full range Futaba setup in the same place...

 

[monki77]

Antennas are pointing at the AC like the manual advises.

They shouldn't be pointing at the drone really, I've attached an image just incase we're not on the same page.

Alyhough! I wish I'd never read this thread now, you've cursed me!

I flew the P4 today in a very large grassy open courtyard and yet even at sub 80m maybe even 50m....I was having disconnect issues and horrible streaming problems.

I took my own advice and checked the transmission channel and it was manually set to 16, no idea why as my iPad is set to UK location and the DJI forces it to auto because of this (Most likely the reason yours is stuck on auto). Anyway... Changed it to auto and it got better but still wasn't perfect.

Now i need to take it somewhere else and make sure it was like you say, not just a bad area.

 

[Ilmis]

They shouldn't be pointing at the drone really, I've attached an image just incase we're not on the same page.

Oh I see, you're right... Thanks!