Mavic 2 Pro Flyaway - Please Help Explain

[slup]

...but the battery is damaged too. There is a major deviation on cell 2 throughout the flight.

That's not correct ... the deviation that reached 0,16v at maximum was starting in the very end of the available log when the battery was on 1%. It wasn't causing the incident it was a consequence from deep discharging the battery.

 

[Yvan]

Sorry, I had not looked well but I see that it starts at 14m 55s. Thank you for correcting me.

 

[Radius]

Wind resistance is measured near sea level, battery life too and don't miss thin air

 

[MS Coast]

Turbulence definitely on the downwind side. But not just turbulence; the Bernoulli effect can produce significantly higher wind speeds, too. Especially directly above and downwind of the ridge or peak.

6f - Wind-Exposed Areas

www.eoas.ubc.ca

There's often very smooth laminar lift on on the upstream side, too. That's what makes ridge soaring in gliders so much fun.

 

[Droniac]

The reason for the incident is very simple and should have been obvious to you.
In just one word it was ..... WIND
You don't seem to have had any idea of the wind and what that was doing to the drone.

Your drone was responding to your control inputs, but the headwind was more than it could fly against.
Here's a slightly longer version of what happened.

As you climbed above the launch point, you failed to notice that there was a significant wind and the drone was having difficulty holding position.
At almost 400 ft the drone was being blown at 3-8 mph by gusty winds.
There was also a strong wind warning at 50 seconds.

You also didn't pay attention to the wind direction and flew the drone off downwind.
You lost signal at 123.5 seconds with the drone 1470 ft from home.
Signal was re-established at 472 sec with the drone now 3755 feet away in RTH but and being blown backwards at up to 5 mph.
You let the drone be blown further away and started descending at 506.4 sec.
You also tried pushing the right stick forward and the drone started to make slow headway against the headwind at times and going backwards at others.

At 541.8 sec you initiated RTH again and left the drone to be blown further backwards as it tried to RTH against a headwind.
At 695.9 sec you cancelled RTH again and resumed control.
At full stick the drone was still blowing backwards slowly.
At 714.3 sec ith the battery at 12% you tried RTH again.
Shortly after at 726.3 sec, the drone commenced autolanding because the battery had reached critical low voltage.

The battery ran out at 972.7 sec.

The place to look for it is: 20.77686 -156.25629
It's possible that it landed or was very close to the ground when the power ran out so you may be in luck?

You’re a drone crunch profiler. well, Dang!! It explained it as you were in it. I’m certain it was appreciated. Awesome. Godspeed, Droniac

 

[TheSnowyPilot]

Hello everyone, new member here, and I'm very glad I found this forum!

I want to start by giving some context on myself as a flier. I've been flying my Mavic 2 Pro for about a year, and I've never really had any safety issues. I have a recreational drone license and I read the manuals carefully. I'm a fairly frequent flier and I've logged many hours of flying since I've gotten the drone.

Fast forward to today, I was out by a mountainside, somewhat high up (~7000ft elevation) but definitely within the working bounds of the drone, and trying to film a video of the afternoon sun above the clouds. I launched my drone by a roadside, well clear of any vehicles and pedestrians, and started filming my video. 2 minutes later, I lost downlink with the drone, possibly because there was some trees blocking the radio signals. At that point, my controller indicated that it had switched to "Return to Home" mode, which I expected it to do so since in the few times that I've had connections issues with my drone, my drone automatically switched to Return-to-Home and came back successfully. However, I waited for 5 minutes and still the connection had not been restored, so I drove a little further, to an area I believed would no longer be blocked by said trees, and reestablished connection with my drone. However, to my horror, the drone, during the 5 minutes of disconnection, had flown almost a kilometer away and was definitely not heading back towards the original launch site. What was even more troubling was the controller and the DJI GO 4 app were both showing the drone was in Return-to-Home mode. So, I tried to switch to manual control in order to manually fly it back, but quickly realized the drone was not responding to my inputs---despite being on full throttle, it would not move in the direction of my controls. At this moment, the low battery warning began to flash so I decided to just let the drone handle Return-to-Home like it always does when it's on low battery, but again, it failed to fly towards its starting point. Instead, it drifted away from me, decreasing in altitude, and eventually, when the battery ran out, it appears to have crashed. During its last minutes, the low battery warning automatically trigged it to land-in-place, which made it descend along the side of the mountain, The last transmission I received showed it being ~750 feet below my starting altitude. Unfortunately, the crash site is nowhere close to the road and the trek down the mountainside seemed too dangerous, so I wasn't able to retrieve the drone.

I've uploaded my flight record to AirData and the shareable link is here: (you can download the original txt file from it). I've also uploaded my DAT files to a Google Drive folder here. If any of you are able to help me understand why my drone flew away, that'd be greatly appreciated!

A final question: when I bought the drone, I also purchased DJI Care Refresh alongside it (for precisely incidents like today), and the 1-year term on it hasn't yet expired. Since I can't retrieve the drone, I'm unsure if my DJI Care Refresh would cover this incident. Does anyone have any advice on what I can do? Is there still a way to somehow use DJI Care Refresh to get a replacement? It'd really suck if this becomes $2k down the drain...

The way I see it after my own incident of flying at height is that if your drone loses connection somewhere high with a lot of wind, and then going into return to home, it gives up the active pressure of returning to home that you would be providing to return at a steady pace.
Pretty much what happened is when you stopped controlling it the wind took advantage and swept it off course with little resistance to the attempt.

I just realised I replied to this a month too late, that drone will be toast by now.

 

[MAvic_South_Oz]

Thank you for the wind data! That would explain why it couldn’t fight against the headwind.

Given these conditions, would there have been any way for me to recover the drone, once it was in the air? What maneuvers would I have needed to perform? Or was drone doomed as soon as I decided to fly it?

Further to other advice regarding when in the air, GO4 has an excellent attitude bowl that virtually tells you what the wind is doing to your drone.
If you managed to get a new M2P, check it out.
If you MUST fly in what seems like higher winds for whatever reason, at least always fly into the wind first and do hover tests at various altitude increases checking the drones attitude as you go.

 

[tlswift58]

Further to other advice regarding when in the air, GO4 has an excellent attitude bowl that virtually tells you what the wind is doing to your drone.
If you managed to get a new M2P, check it out.
If you MUST fly in what seems like higher winds for whatever reason, at least always fly into the wind first and do hover tests at various altitude increases checking the drones attitude as you go.

Apps like UAVForecast have wind speed readings at altitude to show you red (don't fly) or green for wind conditions that you can also set as a maximum. I have mine set for about 250 ft and like 20-25 max mph, as that is pretty typical for my ceiling height during flying, but also gives me some indication should I need to go higher as well.

Just knowing what the wind speeds are before taking off is critical. Not knowing is the recipe for disaster, which you found out the hard way.

 

[MAvic_South_Oz]

Apps like UAVForecast have wind speed readings at altitude to show you red (don't fly) or green for wind conditions that you can also set as a maximum

Yes a good app to have for sure.
I don’t use it a lot though, too many variables, mostly terrain related.
As an avid bushwalker, I’m all to well aware of the fact ‘mountains make their own weather’.
I prefer to check Ventusky when planning a flight day, usually a day in advance before heading out (even before charging batteries) to ensure general conditions look ok.
Then assess wind especially at various times on site, and when I move around to locations.
Our own senses are always best on the spot I find.
It’d be nice to get an update from the OP as to status from DJI and if he mow has a new M2P.
I suspect no normal cover with warranty or normal Refresh, but they might have had the flyaway replacement Refresh option available.

 

[tlswift58]

Yes a good app to have for sure.
I don’t use it a lot though, too many variables, mostly terrain related.
As an avid bushwalker, I’m all to well aware of the fact ‘mountains make their own weather’.
I prefer to check Ventusky when planning a flight day, usually a day in advance before heading out (even before charging batteries) to ensure general conditions look ok.
Then assess wind especially at various times on site, and when I move around to locations.
Our own senses are always best on the spot I find.
It’d be nice to get an update from the OP as to status from DJI and if he mow has a new M2P.
I suspect no normal cover with warranty or normal Refresh, but they might have had the flyaway replacement Refresh option available.

Sounds like you have a good checklist to follow - which most new pilots doubtfully have and should - but that is also part of the learning process for us all. Add some stuff / take some off as time goes by to make our flights hopefully do as intended.

I live and fly in the mountains of Western NC and it definitely is different flying at my home at 2,500 ft elevation and going up to my fav and closest waterfalls / river that ends up about 4,500 ft. It can be bright and sunny at my home and the 12 mile drive up can change radically - due to weather currents. Yet, I do have something of a base to work with and changing locations on UAV will also give me some indication of weather, wind, and overall flying conditions. Then it's my call to decide if I want to play that day. Again, most of my flying is lower level - 10 to about 150 feet and we do have a lot of tree coverage to help slow wind at that altitude to some degree. I get more wind action closer to falls than typically at 100-200 ft; so a watchful eye is a must, esp in ATTI Mode which happens frequently. That's a real butt clincher there! LOL

 

[MAvic_South_Oz]

but that is also part of the learning process for us all. Add some stuff / take some off as time goes by to make our flights hopefully do as intended.

Yep, hopefully get through the basic learning curve with drone intact ?
A bit of luck helps too, had my one little crash.
Having this forum as a newbie (an average, or veteran pilot) helps immensely, the crash section is worth spending time reading the stories and analysis.
I joined very soon after getting my M1P and it’s definitely the pinnacle of DJI Mavic education right here.

 

[Meta4]

The way I see it after my own incident of flying at height is that if your drone loses connection somewhere high with a lot of wind, and then going into return to home, it gives up the active pressure of returning to home. ...
Pretty much what happened is when you stopped controlling it the wind took advantage and swept it off course with little resistance to the attempt.

The drone never "gives up" attempting to return home.
But if the return home is against a headwind that is too strong, the drone won't make it.
It's like rowing upstream against a 5 mph current, when you can only row at 3 mph.

 

[Yaros]

Thank you for the wind data! That would explain why it couldn’t fight against the headwind.

Given these conditions, would there have been any way for me to recover the drone, once it was in the air? What maneuvers would I have needed to perform? Or was drone doomed as soon as I decided to fly it?

Lower the altitude always when you see the drone fly away, probably it's because of the wind, so the wind will be blocked by the mountain and trees on lower altitudes, then you could bring it back to you!

 

[MAvic_South_Oz]

Regarding the posts about RTH, just ensure RTH is set for the minimum (+ a safety margin) for the tallest objects in the area you'll be flying.
No good having it set to maximum 120m, where the wind is probably stronger, when 30m would be ample.

Following Yaros's advice above is good, just be aware if dropping below LOS in cover of terrain or trees, signal may be lost and failsafe RTH kick in, so that's why RTH altitude is so important for each flight, to avoid unnecessary wind up higher.