P3 Pro never came back home

kaotic1 · Jun 27, 2016

What's up everyone, just trying to see if anyone has experience what I had the displeasure of experiencing this past weekend and find out what could have possibly gone wrong.

I am completely sick to my stomach right now with what happened. And DJI's customer service don't even open til tomorrow morning so I've been stuck with this feeling all weekend.

To preface my story, I've owned and flown a P3 Standard since early March of this year and was flying expertly and with full confidence. I recently upgraded to the Pro because I wanted the 4K and longer range. I've flown it just 6 times before this past Saturday, max distance was a little over 1.5 miles.

So I went on a very popular hiking trail in my area, only 3,481 feet in elevation from sea level. Many people have flown here before, a guy flew his around just before I did with no issue. When he was done I set up my Pro and sent it out like I always do, compass calibrated, home point set, 15 sats connected, 97% battery. I reached about 1,400 ft and turned it back around when I started to get the "Image Tranmission Weak" notification. The problem occurs when I am heading back. I'm flying back manually and just as I look down to see how far I am away(9xx ft.), I get the dreaded "No Signal" notification, screen on my Samsung Galaxy tablet goes completely grey and black. No worries I thought, this has happened before, I had full confidence in DJI's famous RTH function. Except only this time it completely failed me!

I waited a few secs. after the "No Signal" and waited for my RC to beep letting me know that it's returning home but after it didn't I went ahead and pressed the RTH and just as expected it beeped, RC LED is red, showing it's coming home except it never did. After a couple mins panic started to set in, heart was pounding, it shouldn't be taking this long to come back it was under 1,000 ft away. There was 21 mins left of flight time when everything lost signal so I patiently waited and waited, but it never showed up.

I feel betrayed, I don't know how else to explain it. I can't even find comfort in my cached video, it cuts off at the exact moment I lost signal so I have no idea what happened. Have no access to my flight log.

Has anyone ever had this happen to them?

With The Birds · Jun 27, 2016

What app were you flying with? Are you saying a flight log wasnt created?

What where your RTH settings? Was the RTH height sufficient to clear all obstacles on the path home?

kaotic1 · Jun 27, 2016

With The Birds said:
What app were you flying with? Are you saying a flight log wasnt created?

What where your RTH settings? Was the RTH height sufficient to clear all obstacles on the path home?

I was flying with the DJI Go app. A flight log was created I'm sure but I have no idea because I lost my bird. It never came back home.

My RTH was set to 120m, trees around me was no higher than 60 ft. I flew it out from the edge of the cliff out into wide open space and there wasn't any obstacle in it's path. I am baffled.

With The Birds · Jun 27, 2016

kaotic1 said:
I was flying with the DJI Go app. A flight log was created I'm sure but I have no idea because I lost my bird. It never came back home.

My RTH was set to 120m, trees around me was no higher than 60 ft. I flew it out from the edge of the cliff out into wide open space and there wasn't any obstacle in it's path. I am baffled.

I understand you dont have the benefit of viewing the log from the AC but GO should have created a log file. Worth looking at. Tou may get an idea of where to start looking.

Meta4 · Jun 27, 2016

kaotic1 said:
I feel betrayed, I don't know how else to explain it. I can't even find comfort in my cached video, it cuts off at the exact moment I lost signal so I have no idea what happened. Have no access to my flight log.

The app has your flight record.
Go to https://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.

If you are using an Android phone or tablet, the flight records are in Internal Storage/DJI/dji.pilot/FlightRecord
They are all txt files and the file name includes the date.

Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident and maybe point to a likely search area.
What were the wind conditions when you were flying?

kaotic1 · Jun 27, 2016

With The Birds said:
I understand you dont have the benefit of viewing the log from the AC but GO should have created a log file. Worth looking at. Tou may get an idea of where to start looking.

I just looked at the flight log. Bird went the complete opposite direction instead of coming to the home point, it was off by more 1,000 ft.

kaotic1 · Jun 27, 2016

Meta4 said:
The app has your flight record.
Go to https://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.

If you are using an Android phone or tablet, the flight records are in Internal Storage/DJI/dji.pilot/FlightRecord
They are all txt files and the file name includes the date.

Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident and maybe point to a likely search area.
What were the wind conditions when you were flying?

Ok, thanks.

Very light breeze this morning of my flight. I've flown it over a large river and canyon area with strong winds and over the Pacific and never had any issue.

But, I will post the log shortly.

kaotic1 · Jun 27, 2016

Link to flight log and report.

Phantom Log Viewer - PhantomHelp.com

Meta4 · Jun 27, 2016

kaotic1 said:
Link to flight log and report.
Phantom Log Viewer - PhantomHelp.com

The altitudes in the flight record look very low ... like you hardly flew above launch height.
Is that correct?

kaotic1 · Jun 27, 2016

Meta4 said:
The altitudes in the flight record look very low ... like you hardly flew above launch height.
Is that correct?

Correct. When I took off from the ledge I flew it straight out over the lake which was 1,000 ft below so I never took the bird up that much higher.

kaotic1 · Jun 27, 2016

So it looks like it never even attempted to climb to RTH height and head home, even though my RC was telling me otherwise. Wow.

Meta4 · Jun 27, 2016

kaotic1 said:
So it looks like it never even attempted to climb to RTH height and head home, even though my RC was telling me otherwise. Wow.

Looks like terrain might be a problem.
I have to come back for this in a little while.

kaotic1 · Jun 27, 2016

Meta4 said:
Looks like terrain might be a problem.
I have to come back for this in a little while.

Ok, no problem. Thanks.

Meta4 · Jun 27, 2016

Here's what I can see so far:
The Phantom was at about the same level as the launch point (1850-1900 feet ASL) when signal was lost.
To the west of home (in the direction of the last record), the land rises to about 200 feet above home point.
The Phantom was flown in from the south until signal was lost behind this higher ground which would have blocked signal.
The RTH altitude setting of 400 ft would have been high enough to clear this if RTH was activated.
Initially the downlink was lost but restored after 1.5 secs.
This was probably due to patchy line of sight through treetops but if the Phantom flew a little further along higher ground would have completely blocked signal.
Because the Phantom was hidden behind terrain, we can't tell what happened next.
If RTH was triggered on loss of signal, the Phantom should have climber 400 feet (well above terrain) and come home.
It would have reestablished signal as it climbed.
I can't see any evidence to show why this didn't happen.
If the Phantom just hovered, it may have gone down around the last GPS location shown in the flight record?

Flying behind terrain is not a good idea.
If the Phantom had been raised to maintain LOS everything would have been sweet.

kaotic1 · Jun 27, 2016

Meta4 said:
Here's what I can see so far:
The Phantom was at about the same level as the launch point (1850-1900 feet ASL) when signal was lost.
To the west of home (in the direction of the last record), the land rises to about 200 feet above home point.
The Phantom was flown in from the south until signal was lost behind this higher ground which would have blocked signal.
The RTH altitude setting of 400 ft would have been high enough to clear this if RTH was activated.
Initially the downlink was lost but restored after 1.5 secs.
This was probably due to patchy line of sight through treetops but if the Phantom flew a little further along higher ground would have completely blocked signal.
Because the Phantom was hidden behind terrain, we can't tell what happened next.
If RTH was triggered on loss of signal, the Phantom should have climber 400 feet (well above terrain) and come home.
It would have reestablished signal as it climbed.
I can't see any evidence to show why this didn't happen.
If the Phantom just hovered, it may have gone down around the last GPS location shown in the flight record?

Flying behind terrain is not a good idea.
If the Phantom had been raised to maintain LOS everything would have been sweet.

Flying behind terrain is a bad idea but I wasn't flying behind any terrain. P3 was in wide open skies somewhere in front of me, only 900+ feet out when it lost signal coming back, which is a shame considering what the P3Pro is rated at in range. Not even 1/2 mile out and I start to lose image transmission with Light Bridge is also a shame.

kdrak · Jun 27, 2016

I cannot see any message on the logs that mentions RTH was activated !

kaotic1 · Jun 27, 2016

kdrak said:
I cannot see any message on the logs that mentions RTH was activated !

I don't see it either. And that is the troublesome part because I activated it twice. First time was after it didn't initiate RTH on it's own after losing signal. And then again after waiting about 5 mins and it still didnt show up. My RC was beeping indicating that it was in RTH mode. Apparently not.

kdrak · Jun 27, 2016

So the problem here is that the aircraft never received a RTH signal.

kaotic1 · Jun 27, 2016

kdrak said:
So the problem here is that the aircraft never received a RTH signal.

It appears so. I always fly with my antennas in the correct orientation in relation to where the aircraft is too so I don't know what the hell happened. Totally disappointed in DJI at the moment.