Close call flyaway

mattydrone · Feb 27, 2017

On 2/26/16 I decided to test out facebook live for the first time. I decided to take my mavic pro behind my house, over the woods and into a development behind me where my cousin lives. This is my first time taking it this far. This video starts after i made it over into the development to save time.

Before my flight i made sure to calibrate my compass, my imu's & before take off i set my homepoint and showed I had 18 satellites. I did fine until I got over my cousins house. I set my height at 300 feet. I stopped over my cousins house which was around 2,200 feet away from me. After looking down at him (he came outside and to see it), i panned around to get back in my direction so i could return home. It was then (at 2:11) when i started getting an error message that talked about possible obstructions which is odd because i had nothing around me.

I freaked & hit RTH but it did nothing. For the next several minutes all i could do is watch while it drifted to about 2300 feet away, then the next thing i know it started to drift higher and higher to around 900 feet! Then at around 2:50, it climbed to 1,000 feet. I have it capped at 400ft. so I'm not sure what happened here. Finally at 5:15 it started acting like it was going to return home, but then It backed up a couple times and rose even higher! It rose to over 1,100 feet!

After a couple times of canceling the RTH and doing it again, it finally worked around 7:57. After a nerve racking 10 minutes+, it finally landed with only 2 minutes to spare on the battery!!

Any idea how can i determine what went wrong?

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msinger · Feb 27, 2017

Please upload your TXT flight log here and post a link back here.

mattydrone · Feb 27, 2017

i will do this soon as i get home this evening. Thank you!

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Jayfdee · Feb 27, 2017

Wow pretty scary for sure, our worst nightmare. I am sure you will get some help here. Maybe post on the Mavic forum for more insider knowledge.
Glad you got it back safe and sound.

kndll · Feb 27, 2017

Is RTH in meters or feet on the Mavic ?

msinger · Feb 27, 2017

RTH is set in meters.

kndll · Feb 27, 2017

so if he has it set at 400 = 1300 ft

msinger · Feb 27, 2017

Right -- it would be 1,312 feet.

tjshelton · Feb 27, 2017

I've not experienced it, but I think I've read in another post that looking into the sun can confuse the obstacle avoidance system. It looks like something like that might have happened here. You got some significant glare right around the time you said you got the OA warning.

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dwallersv · Feb 27, 2017

tjshelton said:
I've not experienced it, but I think I've read in another post that looking into the sun can confuse the obstacle avoidance system. It looks like something like that might have happened here. You got some significant glare right around the time you said you got the OA warning.

This was my thought as well. The subsequent behavior -- climbing, pausing, moving around a little, climbing again, etc. -- is just what it does when it's trying to go over the top of an obstacle during RTH.

Meta4 · Feb 27, 2017

dwallersv said:
This was my thought as well. The subsequent behavior -- climbing, pausing, moving around a little, climbing again, etc. -- is just what it does when it's trying to go over the top of an obstacle during RTH.

This sounds likely and perhaps the flight log will clarify.
If it's an issue with RTH being unwilling to fly into a low sun, that would be easily addressed by turning off the object avoidance.
If there's nothing to hit, there's no need to leave it running.

mattydrone said:
Before my flight i made sure to calibrate my compass, my imu's

ALthough it's not relevant to what happened in this flight, it all sounds like you are being too careful, doing things that are quite unnecessary in the mistaken belief that they make you safer.
Look at the top of page 50 in your manual to see what DJI say about when you need to recalibrate the compass.
And there's no need to recalibrate the IMU before a flight either.
But unnecessarily recalibrating the compass in a (magnetically) bad location will give you some new problems to deal with.

mattydrone · Feb 28, 2017

I tried to locate the log but when I pull up that folder and click on the only .txt file I'm only showing data from an upgrade I did over a week ago and that's it which is kind of odd. I am going to the miscellaneous folder...should I be going somewhere else? does it still capture data if I'm not recording? The footage you see is from my Facebook, not a video file from the drone.

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mattydrone · Feb 28, 2017

also I would like to note that I have my max height set at 122 meters, not 400. I normally only do the compass calibration before a flight not the imu.. i only did that because I planned to take it farther than I have gone before from my house so i was just being cautious.

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msinger · Feb 28, 2017

mattydrone said:
I tried to locate the log but when I pull up that folder and click on the only .txt file I'm only showing data from an upgrade I did over a week ago and that's it which is kind of odd. I am going to the miscellaneous folder...should I be going somewhere else?

See my instructions here.

Meta4 · Feb 28, 2017

mattydrone said:
I tried to locate the log but when I pull up that folder and click on the only .txt file I'm only showing data from an upgrade I did over a week ago and that's it which is kind of odd.

Forget your SD card, the flight record is recorded by the app and is in your phone or tablet.

Thermographer · Feb 28, 2017

I read on another forum, that DJI has made a correction in there manuals to only calibrate the compass when the app tells you to. Distance from original calibration is no longer a factor.