Hi, all

Does anyone happen to have a direct call-back number for DJI's North America Management Team? I've been playing phone tag with an individual. I am in meetings nearly all day, and I cant step out of a client meeting to answer calls, so I've missed his calls with no way to contact directly back.


I had a Mavic Pro Platinum that was ~7500 feet away, moving @ ~27mph towards me, with 6mins of flight time remaining (at this distance, the flight home would take 3min 5sec, per my calculations utilizing the flight data that DJI and I agree on, via flight records). At this distance, the app disconnected for no discernable reason. I utilized the hard button on the controller for Return-to-Home, but nothing happened. I ended up trying to fly the aircraft back to me, by reducing the horizontal distance parameter shown on the controller. Unfortunately, without GPS/Map assistance, or a functioning camera feed (I was unsuccessful in getting my phone-controller connection back up, despite my best efforts), I was unable to determine if the vector the aircraft was on was directly at me. I assume it was not, as I flew @ 25-30mph for the next 5 minutes (remember, the aircraft was 3:05min of flight time away), before the battery got too low. At this point, i was able to cover 1500 horizontal feel of closure, but the aircraft was at 5100 feet away when the battery got critically low and the aircraft landed.

I submitted a case, my flight data was reviewed, all parameters on distance, speed, and flight-time remaining were about exactly what I am able to last see on my flight records.

However, upon "review", DJI has told me that the aircraft loss is due to pilot error, because I did not watch the battery level.
I'm not exactly sure how that conclusion could be drawn, given that we agree on the distance and speed the aircraft was at, and both DJI's and my Flight Record's show the same battery time remaining.

I am looking to actually speak with someone on the NA Management Team on how, given the Flight Data and mathematical calculations showing there was 2x the battery capacity needed, the loss could be attributed to the "Pilot Error"?



I cant keep receiving calls while I'm at work, in meetings, with no ability whatsoever to get directly back with the team I need to speak with. I have not yet been given any direct callback number or ability to schedule a precise time for a call... this is all I want. I just want to go over my data, and find out how this conclusion was drawn, and talk about it.

For reference, here is a screenshot of the DJI Provided, last flight log info

Good luck reaching someone in NA that can actually do more the repeat the initial analysis. You were 900 ft of altitude and over a mile out with 6 minutes of battery left. The mavic will auto land at 10% battery. Pretty close to the edge of the envelope. Did you try Find my Drone?

I used find my drone. Unfortunately, all mapping services stopped when the app disconnect. I hiked out to the position that the "find my drone" function gives, but that is 7600ish feet away and there was nothing there. Per the controller's data, i was at 5100ft when it hit 10% and started landing.
At this point, without a drone to test on.... I still dont even know if its the cable, controller, app, etc... that caused the disconnect. The app didnt crash, it just went grey and stated "Disconnected".

I'm not even asking for 100% warranty replacement right now. I just want a good discussion, and a logical answer.
Another issue I find "interesting", is that DJI was able to provide a screenshot of my flight at the same coordinates as my flight log, with the same distance and speed, yet their log shows 24sec less flight time remaining, and 7% less battery than my App's flight log.

As for the 900ft altitude: Yes, but as I was flying in a mountainous region, this was less than 300ft above the ground, from my view.
As for the over a mile out: Agreed, this was a ways out.... but I had about 2x the flight capacity needed to get home, without hardware or software failure, per my math....

At the moment, I cant even get someone to give me a solid attempt at reconnecting. Just calls and reiterative, canned answers, it seems.  

I understand what you're requesting, it's just that I've never heard of anyone getting an interactive flight analysis. My guess would be that if they did it once they would be on the hook for every nonsensical request. You seem well versed on the capabilities of the Mavic but I always thought the height was the distance above the takeoff point, not above sea level. Anyway, good luck!

Unfortunately, there is not a way to schedule a call. However, if you provide me your case number, I will see if I can assist. For the record, the flight records do provide a conclusive analysis on what has happened during the flight. It is based on software analysis that is exclusive for flights. If you are flying at a limited amount of battery life left, that could be a strong point for pilot error. It is also important to recognize that drones are never set to be flown out of site. If you send me a personal message with the case number, I may be able to see further on what is going on with this.  Keep in mind that if such analysis of flight records conclude that it is pilot error, the conclusions are usually well founded.

ghostrdr Posted at 2018-3-1 10:09
I understand what you're requesting, it's just that I've never heard of anyone getting an interactive flight analysis. My guess would be that if they did it once they would be on the hook for every nonsensical request. You seem well versed on the capabilities of the Mavic but I always thought the height was the distance above the takeoff point, not above sea level. Anyway, good luck!

Well,

In the '500 meter" limit, the height is above takeoff point.

In the "400ft" limit, set by the FAA, it is above ground, i believe.

It indeed looks like you forgot to take the height into the equation, total flytime to Homepoint would have been 4 minutes 50 seconds (313.8/3) + (2294/12.4).
At those heights a low battery landing would kick in earlier than at 10%, see this topic.

LoSBoL Posted at 2018-3-1 11:34
It indeed looks like you forgot to take the height into the equation, total flytime to Homepoint would have been 4 minutes 50 seconds (313.8/3) + (2294/12.4).
At those heights a low battery landing would kick in earlier than at 10%, see this topic.

You bring up a very good point! I did not show that I took vertical distance into account. However, being that you can descend without slowing forward progress (or so I believe), i would be descending this entire time.
So, within the 3.08 minutes of time spent OMW back, I would have been descending @ 3m/s. Therefore, I would have needed to descend for 104.6 seconds, or 1.74 minutes. This is not a "sum of two" scenario, as each action is not mutually exclusive. They can be carried out simultaneously.
Also, I have to clarify. I was flying nearer the base of a mountain. So the height of 314m (1029ft) was required, as there was a mountain ahead of me that was about 600-700 feet higher than takeoff point.


However, I want to get back to the main catalyst and cause of the issues here:
The random disconnection of the app from the controller.

All things considered, the flight was normal and would have completed as normal, without this event. We could argue that the planning on my part took a higher risk than I *could* have, but regardless. The data given here mathematically shows the flight could have (and I posit it would have) concluded as normal, without this single hardware/software problem.

Lets put it this way, if youre driving home... and your gas light comes on.
You have 40miles left to empty.
You have 20 miles left til youre home.
You're gonna make it home, right?

Now, I blindfold you and take away your navigation.

Is it your fault for not watching your fuel gauge and filling up earlier? or is it my fault for taking away your ability to navigate?

LoSBoL Posted at 2018-3-1 11:34
It indeed looks like you forgot to take the height into the equation, total flytime to Homepoint would have been 4 minutes 50 seconds (313.8/3) + (2294/12.4).
At those heights a low battery landing would kick in earlier than at 10%, see this topic.

I was also unaware that at certain heights, the auto-land feature is enabled earlier.

Interesting, but from a safety standpoint, that kinda makes sense.....

Flite Posted at 2018-3-1 12:40
I was also unaware that at certain heights, the auto-land feature is enabled earlier.

Interesting, but from a safety standpoint, that kinda makes sense.....

Me neither, untill I read the topic I've linked.

It does indeed make sense though from a safety perspective. And if you did have a connection, and were able to overide the automated low battery landing procedure, you could have made it home.

I understand though that the Mavic leans toward the safe side when doing its calculations.

You can, somewhat, override the auto-land. If you keep the left stick up, it will counter-act the auto-land feature, at least to a point.

I tried this. The issue is that I couldnt clearly see exactly which way the aircraft was pointed as it flew closer to me. The Horizontal distance diminished, but that doesnt say whether or not it was also traversing left or right as it got closer. Without the knowledge of the vector the aircraft was on, I was unable to bring it right to me, as I had done 30 times before.

I can understand wanting to figure out why your app disconnected but this is definitely pilot error. If you post your log from the RC you can get coordinates of the drone before it disconnected from RC.

The coordinates from before it disconnected are really of no use, as I'd made it 2600 feet closer.

Hi Flite, we are so sorry for your loss, as Mark mentioned, there is not a way to schedule a call. Please provide us your case number, we will help to check the flight records to see if there is anything we can do for you, thank you.

I need the/a drone for a trip I'm taking in 8 days, so I will just have to accept the offer I've been given, I guess....

Flite Posted at 2018-3-5 05:49
I need the/a drone for a trip I'm taking in 8 days, so I will just have to accept the offer I've been given, I guess....

The data analysis is based on the flight records you offered. Anyway, all of us keep learning and moving on. Feel free to contact us if there are further questions.

All,

I have to say, my thoughts have turned a corner. I PM'd DJI-Mark. He was able to provide more information in 3 hours than I was normally getting in 2+ days!