“Aircraft disconnected” “return to home” scare.

[Lapeer20m]

We were flying an m210 today and intermittently the aircraft appeared to stop in mid air and no longer accept stick inputs from the remote controller. We thought it was the vision positioning system putting the brakes on.

We were flying over a lake that was frozen and we’re almost back to the home point when the aircraft simply decided to auto land, seemingly without notice. Pushing full up on the stick did nothing.

Had great signal strength and video was clear.

No warnings on the screen.

This was probably 20’ from remote controller.

Returned to the station, utilized sssistant 2 to re-install firmware (was already on latest version)

Powered up aircraft, linked the slave remote controller as the master. Everything appeared normal.

Took off, hovered, all the controls functioned normally.

Flew around an empty field for a couple of minutes, then “aircraft disconnected” and RTH was automatically initiated. Distance was about 100 yards.

For the remainder of the flight the aircraft refused to accept any stick inputs. Live video feed was still on the screen of the crystal sky, and I’m pretty sure telemetry data was still
Being displayed on the rc, but the aircraft acted like the remote controller signal was lost.

It was a tense minute or two, but matrice auto landed in the empty parking lot near where it took off from.

I’ve been flying dji drones for a couple years with hundreds of miles and countless hours under my belt. This was a first for me. Tomorrow I’ll start a claim with dji to get the aircraft sent back and repaired under warranty i assume? It’s only about 4 months old.

 

[Mixchief]

I wondered if the Enterprise birds were free of pain, now I see they are not, sorry to hear, at least you weren't. smile out to sea when it decided to land

 

[JDSimpson]

We were flying an m210 today and intermittently the aircraft appeared to stop in mid air and no longer accept stick inputs from the remote controller. We thought it was the vision positioning system putting the brakes on.

We were flying over a lake that was frozen and we’re almost back to the home point when the aircraft simply decided to auto land, seemingly without notice. Pushing full up on the stick did nothing.

Had great signal strength and video was clear.

No warnings on the screen.

This was probably 20’ from remote controller.

Returned to the station, utilized sssistant 2 to re-install firmware (was already on latest version)

Powered up aircraft, linked the slave remote controller as the master. Everything appeared normal.

Took off, hovered, all the controls functioned normally.

Flew around an empty field for a couple of minutes, then “aircraft disconnected” and RTH was automatically initiated. Distance was about 100 yards.

For the remainder of the flight the aircraft refused to accept any stick inputs. Live video feed was still on the screen of the crystal sky, and I’m pretty sure telemetry data was still
Being displayed on the rc, but the aircraft acted like the remote controller signal was lost.

It was a tense minute or two, but matrice auto landed in the empty parking lot near where it took off from.

I’ve been flying dji drones for a couple years with hundreds of miles and countless hours under my belt. This was a first for me. Tomorrow I’ll start a claim with dji to get the aircraft sent back and repaired under warranty i assume? It’s only about 4 months old.

I have an M210RTK and thank goodness I have not experienced your particular situation. Please let us know what DJI says about this. I am wondering if you tried downgrading the firmware to see if the problem still exists? Thank you for sharing.

Regards,
JD

 

[Joseph perez]

We were flying an m210 today and intermittently the aircraft appeared to stop in mid air and no longer accept stick inputs from the remote controller. We thought it was the vision positioning system putting the brakes on.

We were flying over a lake that was frozen and we’re almost back to the home point when the aircraft simply decided to auto land, seemingly without notice. Pushing full up on the stick did nothing.

Had great signal strength and video was clear.

No warnings on the screen.

This was probably 20’ from remote controller.

Returned to the station, utilized sssistant 2 to re-install firmware (was already on latest version)

Powered up aircraft, linked the slave remote controller as the master. Everything appeared normal.

Took off, hovered, all the controls functioned normally.

Flew around an empty field for a couple of minutes, then “aircraft disconnected” and RTH was automatically initiated. Distance was about 100 yards.

For the remainder of the flight the aircraft refused to accept any stick inputs. Live video feed was still on the screen of the crystal sky, and I’m pretty sure telemetry data was still
Being displayed on the rc, but the aircraft acted like the remote controller signal was lost.

It was a tense minute or two, but matrice auto landed in the empty parking lot near where it took off from.

I’ve been flying dji drones for a couple years with hundreds of miles and countless hours under my belt. This was a first for me. Tomorrow I’ll start a claim with dji to get the aircraft sent back and repaired under warranty i assume? It’s only about 4 months old.

Do your self a favor by the marco polo locator. What my inspire 2 flew of I lost GPS on the drone and the GPS locator and I never got a GPS signal for the 2 hours I looked for it and I never got it for. The Marco polo dosen't use GPS and it works great. I had to buy a new inspire 2. You can't depend on GPS for some reason and I have been flying in the same parking lot for 3 and a half years.

 

[Dobmatt]

I wondered if the Enterprise birds were free of pain, now I see they are not, sorry to hear, at least you weren't. smile out to sea when it decided to land

The one and only machine always working flawlessly was a well on my grandma's backyard. Until one day a chain link broke and the bucket landed at the bottom ...

 

[Mixchief]

The one and only machine always working flawlessly was a well on my grandma's backyard. Until one day a chain link broke and the bucket landed at the bottom ...

Did you make a repair ticket with DJI?

 

[Dobmatt]

Did you make a repair ticket with DJI?

Haha, I was 8 when this happen and the well was decades past warranty .

 

[Mixchief]

Haha, I was 8 when this happen and the well was decades past warranty .

typical of DJI to say that!

 

[Lapeer20m]

Did you make a repair ticket with DJI?

Yes.

I posted the .dat file elsewhere which seems to show that there is a really strong link between rc and ac, which streams video and telemetry data to the rc but the aircraft is unable to receive input from the rc.

The general thought is that there may be a firmware issue with the rc. I will try to downgrade the rc firmware and see if this issue persists.

Dji is forwarding the issue to their “senior engineers” and will get back with me.

 

[Lapeer20m]

The lesson I learned in all this is that if flying over water, one needs to make certain the home point is at least 20 meters from the waterline.

While I thought I knew how rth worked, I did not understand at the time that if failsafe rth is initiated within 20 meters of the homepoint, the aircraft will auto land right where it is, rather than the takeoff point.

This is something to keep in mind when selecting your takeoff point.

 

[Mixchief]

The lesson I learned in all this is that if flying over water, one needs to make certain the home point is at least 20 meters from the waterline.

While I thought I knew how rth worked, I did not understand at the time that if failsafe rth is initiated within 20 meters of the homepoint, the aircraft will auto land right where it is, rather than the takeoff point.

This is something to keep in mind when selecting your takeoff point.

Wow dude, you are absolutely right and I never thought of that always flying over water with no way of having that kind of distance, and actually once having battery issues on the way back from a one mile flight, well two miles round trip. In fact on landing the bird was about a meter off and I was just barely able to correct it but it lightly (thankfully) nicked a railing. It could have been much worse.

 

[JDSimpson]

Yes.

I posted the .dat file elsewhere which seems to show that there is a really strong link between rc and ac, which streams video and telemetry data to the rc but the aircraft is unable to receive input from the rc.

The general thought is that there may be a firmware issue with the rc. I will try to downgrade the rc firmware and see if this issue persists.

Dji is forwarding the issue to their “senior engineers” and will get back with me.

Please let us know what the result is after downgrading the firmware. Thanks.

 

[RobH2]

I too would like to know the result after downgrading. I have an Inspire2 but the same issue happened to me with my Mavic Pro Platinum a month ago and I haven't flown since.

My issue may be related to compass but I went to move my father out of his apartment about 300 miles away from my home. I took my drone to simply fly up and do a 360 pano to give him of his old neighborhood. I went up shot and on the way down, just 100 feet directly over my head, in an area with nothing to create interference, I lost connection. I had no control. I turned the controller off and then back on. No control. It finally began to descend but stopped about 6 feet up and never autolanded. I finally had to grab it and manually reach around to the top and turn the battery off to get it to stop. If I had been over water it would have hovered till the battery ran out and dropped.

I have RTH setup to return to the take off location. And RTH, which I seldom invoke (I always return and land manually) has on occasion been used and worked perfectly. I haven't diagnosed yet and need to do a compass calibration and fly again to see if the problem is solved. But, this post is very similar to a scare I had and made me wonder if it was due to a firmware update. I'll keep my eye on this post.

 

[davidjmurray]

The lesson I learned in all this is that if flying over water, one needs to make certain the home point is at least 20 meters from the waterline.

While I thought I knew how rth worked, I did not understand at the time that if failsafe rth is initiated within 20 meters of the homepoint, the aircraft will auto land right where it is, rather than the takeoff point.

This is something to keep in mind when selecting your takeoff point.

Interesting! I fly next to water (or on it) vey often, but never thought about what would happen if a system-initiated RTH happened within 20 meters of the real Home position. I just assumed (always a red flag!) that emergency RTH would happen with the bird far away, and that I'd be able to regain manual control before it actually landed. Sheesh. Thanks for the heads up! Shall have to experiment with this as best I can...in a wide open area far from the ocean. ;-)

 

[Flightline911]

You are describing what I experienced in February 2018, almost verbatim. They are airraft would fly fine and then seemingly for no reason disconnect itself from the controller. While you were still able to receive telemetry via the video display, the aircraft was unable to receive any input from the transmitter. No amount of firmware reflashing would change the outcome. I ended up sending the entire aircraft back to my enterprise dealer who then sent it directly to DJI in California. They overnighted me a replacement bird, but kept me in the loop as to the aircraft status. A failed IMU was the ultimate culprit.

 

[Lapeer20m]

Interesting! I fly next to water (or on it) vey often, but never thought about what would happen if a system-initiated RTH happened within 20 meters of the real Home position. I just assumed (always a red flag!) that emergency RTH would happen with the bird far away, and that I'd be able to regain manual control before it actually landed. Sheesh. Thanks for the heads up! Shall have to experiment with this as best I can...in a wide open area far from the ocean. ;-)

I’m with you! I’ve been flying DJI drones for a couple years now. I even teach police and firefighters how to safely fly drones. Part of our training involves the three types of RTH, but we never actually shut off a controller to initiate rth because we consider it an unacceptable risk to purposely break the link between rc and ac.

As silly as it is, I even have a slide in a PowerPoint that briefly touches on how the ac should respond to rth based upon its distance from the home point, but never really considered this factor when flying near water, or other obstacles.

The 20 meter rule is definitely getting added to the pre flight checklist.

 

[davidjmurray]

we never actually shut off a controller to initiate rth because we consider it an unacceptable risk to purposely break the link between rc and ac.

Interesting. I consider it important to practice dealing with broken links, as they can definitely happen in the real world. To me, it seems like an an unacceptable risk to NOT practice this.

 

[The Editor]

Interesting. I consider it important to practice dealing with broken links, as they can definitely happen in the real world. To me, it seems like an an unacceptable risk to NOT practice this.

Totally agree.
It is in my ops manual to test regularly the RTH works correctly due to both user initiated and loss of signal behaviour.
For a commercial operator it's actually irresponsible not to periodically test it's functionality.

 

[Lapeer20m]

Totally agree.
It is in my ops manual to test regularly the RTH works correctly due to both user initiated and loss of signal behaviour.
For a commercial operator it's actually irresponsible not to periodically test it's functionality.

Interesting thoughts.

While we test rth functionality in two of the three modes, our school of thought is that we found it irresponsible to purposely create a scenario where a rpic has no control over the aircraft during a flight.

 

[The Editor]

Interesting thoughts.

While we test rth functionality in two of the three modes, our school of thought is that we found it irresponsible to purposely create a scenario where a rpic has no control over the aircraft during a flight.

Playing Devil's Advocate - how would you feel if a designed safety feature malfunctioned or failed to operate and you had no idea because you never tested it regularly?
Don't forget a loss of signal in the first instance will simply trigger a failsafe and put the aircraft into stationary GPS hover. Only after a few seconds will RTH kick in.
I actually test signal loss behavior by physically turning off the RC.
Any number of scenarios could cause an rf link failure from the aircraft such as interference, RC battery failure, or any type of fault within the RC itself.
Just the way I personally do things.