Need help on Mavic 2 pro crash from flight records

[Trouter]

flying 1500' from home point, 179' high, 23 mph and lost signal. people at bridge saw big splash. I'm wondering if this is an equipment failure
that DJI might cover

17satellites

179.8ft

N/A

23.5mph

1,578.5ft

82%

15.181V

3.793V

3.792V

3.815V

3.781V

0.034V

Weak signal. Adjust antenna and avoid signal block.; Adjust antenna and avoid signal block

. I have DJI care, tried to dredge up drone in 5' of water to no avail.
Is there something I'm missing on this crash? batteries look good.
I'll attach flight records. Is this this the place to post this? I've been a mavic owner for 4 years but don't post much.

 

[slup]

Nothing abnormal is seen at all ... the log just ends suddenly 167sec after take-off.

There in the end the AC had just ascended up to nearly 54m and started to fly east at a heading speed of 10,5m/s, only commanded with right stick full forward.

The telemetries doesn't show any surprising or uncommanded AC movements at all, yaw, pitch & roll is consistent with how the AC is flown.

In the end the AC had 17 satellites locked & the AC-RC connection was good. The battery had there 82% left with a total voltage of nearly 15,2V ... with the lowest cell on 3,8V.

All relevant data in below chart from where the last ascent starts ... graph explanations under the chart, click on it to make it larger.



And here on a satellite picture ... green bar shows yaw angle.



Usually in cases like this, the reason is a sudden power loss, either a electrical fault or a battery that have come lose or been ejected which terminates everything including further log recording. So the true reason for the incident is hidden outside the log unfortunately ...

Usually DJI wants the AC in order to honor DJI care ... if it's lost, it's a great risk that they will say that nothing in the mobile device logs explain what happened & it can't be proved that it was their fault.

 

[Trouter]

Slup,
Thanks for the quick reply. I was afraid of that. If a battery is loose, shouldn't that have an error code? Wonder why
battery would disengage on a smooth, forward flight. I assume the green yaw angle means it was flying straight ahead.
Would the end of the green line possibly be the water entry point from 179' high with no wind?

 

[slup]

Slup,
Thanks for the quick reply. I was afraid of that. If a battery is loose, shouldn't that have an error code? Wonder why
battery would disengage on a smooth, forward flight. I assume the green yaw angle means it was flying straight ahead.
Would the end of the green line possibly be the water entry point from 179' high with no wind?

It's unfortunately not uncommon at all with ejected batteries from the Mavic 2 series ... perhaps a couple cases each month is seen here at the forum.

The battery might have been perfectly well & didn't show any swelling before the flight ... but as it's no extra room in the AC except for a perfectly flat battery, even the slightest swelling after for instance a full stick ascent followed by a full stick forward made them swell & the battery was pushed out.

In a case as described above ... the power loss is instant ... no error code have the time to be written before all is over.

When the power was cut the AC had a heading speed of 10,5m/s & was 54m up in the air ... so what's shown in the satellite pic isn't where it hit the water.

 

[Trouter]

Wow, maybe zip tie it in. Or get floatation. I thought I was smart, and added Christmas 4" styro balls to leg extentions in the past to float a Mavic Pro.
I took off from my front yard on Lake Superior. It flew away , uncontrolled , over the lake until I shut off the down sensors.
It was constantly trying to get away from its own balls. I castrated it after that.

 

[Made2Phly]

It's unfortunately not uncommon at all with ejected batteries from the Mavic 2 series ... perhaps a couple cases each month is seen here at the forum.

The battery might have been perfectly well & didn't show any swelling before the flight ... but as it's no extra room in the AC except for a perfectly flat battery, even the slightest swelling after for instance a full stick ascent followed by a full stick forward made them swell & the battery was pushed out.

In a case as described above ... the power loss is instant ... no error code have the time to be written before all is over.

When the power was cut the AC had a heading speed of 10,5m/s & was 54m up in the air ... so what's shown in the satellite pic isn't where it hit the wat

Wow, maybe zip tie it in. Or get floatation. I thought I was smart, and added Christmas 4" styro balls to leg extentions in the past to float a Mavic Pro.
I took off from my front yard on Lake Superior. It flew away , uncontrolled , over the lake until I shut off the down sensors.
It was constantly trying to get away from its own balls. I castrated it after that.

Two thoughts :
1. Velcro strap for battery.
2. Comprehensive review on flotation devices here : Best WATER rescue device? MY RESULTS

 

[peterc4]

Exactly the same as me a year ago power failure and gone, dji would not accept responsibiity or look at any third party data which the guys on here done for me which shown the drone loosing power ended up getting 30% of a new one which made me think why give 30% off if my fault, good luck keep us up todate

 

[EricJT]

Wow, maybe zip tie it in. Or get floatation. I thought I was smart, and added Christmas 4" styro balls to leg extentions in the past to float a Mavic Pro.
I took off from my front yard on Lake Superior. It flew away , uncontrolled , over the lake until I shut off the down sensors.
It was constantly trying to get away from its own balls. I castrated it after that.

I tried a reusable zip tie but could never get it snug enough...based on another member's suggestion in another thread, I now use a velcro strap...a bit more work to get in the air each time, but I would rather give up an extra minute than the AC.

 

[pelagic_one]

I have DJI care, tried to dredge up drone in 5' of water to no avail.

I’m very sorry about the loss of your M2P, but I highly admire the recovery effort. The photos appear to show moving water, so I’m picturing it tumbling downstream. Maybe ever so slowly, but definitely away from last detected spot.

With that recovery rig, did you happen to catch any fish? ?

 

[Trouter]

No fish except jellyfish. Did dredge up cans and bottles so it worked. Regarding ejected battery I just got a new mavic 2 and after two flights the battery compartment shows a shiny spot where battery is pressing. I can feel a hump there with my finger. Old battery shows bulge and new one doesn’t. Pilots should take care or always use a Velcro. I will attach photos
Shiny spot from pressure bulge is near the QR code. Batteries are cold

 

[slup]

No fish except jellyfish. Did dredge up cans and bottles so it worked. Regarding ejected battery I just got a new mavic 2 and after two flights the battery compartment shows a shiny spot where battery is pressing. I can feel a hump there with my finger. Old battery shows bulge and new one doesn’t. Pilots should take care or always use a Velcro. I will attach photos
Shiny spot from pressure bulge is near the QR code. Batteries are cold

Yep ... Mavic 2 batteries are much more prone to put direct pressure on the bottom of the battery compartment with the slightest battery swelling.

The batteries for the older Mavic Pro had another design which allowed some small momentary swelling as seen here on the back side from those batteries...



Here a video how easily the M2Pro can pop out with some swelling ... check from 4:47

 

[Trouter]

Great video, thank you very much, that explains a lot. I will sure be Velcro in my batteries. I’m sure that’s exactly what happened. I sent info in to DJI but not sure if they will see it as a hardware problem for DJI care. Will you just retire the swelled battery or do you think Velcro will keep it running?

 

[slup]

...Will you just retire the swelled battery or do you think Velcro will keep it running?

WWW is full of guidance regarding this ... all says the same thing, dispose of it properly.

Here one example --> Puffed Lipo Battery: Why they swell and what to do about it • LearningRC

 

[Trouter]

WWW is full of guidance regarding this ... all says the same thing, dispose of it properly.

Here one example --> Puffed Lipo Battery: Why they swell and what to do about it • LearningRC

Thank you much. Very good Lipo battery article. I charge mine on my car charger. Is the Mavic two battery intelligent enough to leave it connected after it is fully charged , for a few hours.

 

[Trouter]

After loss, got new mavic 2 last week. Now new battery , just 2 flights and it now turns on AC when inserted. Won’t turn off until removed. I think I am hexed.

 

[Thomas B]

After loss, got new mavic 2 last week. Now new battery , just 2 flights and it now turns on AC when inserted. Won’t turn off until removed. I think I am hexed.

Video the event, Contact DJI. Then send it back for replace the as I posted in the separate thread you started regarding this defective battery.

 

[Trouter]

As

Video the event, Contact DJI. Then send it back for replace the as I posted in the separate thread you started regarding this defective battery.

Will do, thanks. I posted a new thread because I didn’t know how very active this forum is

 

[Thomas B]

I read about 2-400/day depending. Sometimes more.

 

[slup]

...I charge mine on my car charger. Is the Mavic two battery intelligent enough to leave it connected after it is fully charged , for a few hours.

For that short period, that wouldn't be a problem... just bear in mind that charging or storing a LiPo in a hot car can make them swell. Room temperature & not charging warm batteries are key words here ...

 

[Trouter]

I read about 2-400/day depending. Sometimes more.

Unbelievable, thank you.