Hey guys,

I crashed a DJI Inspire 1 drone. It was on command for RTH and it was enroute for return to home, as it was hovering above the homepoint after landing gears were lowered it stalled and fell to the ground. I couldn't save it by cathcing, there were some wind and it dragged wide to the side. My friend dashed to try to catch it but it wasn't meant to be, it smashed into logs on the ground. The arm/body hinge was smashed and the front left landing arm was sheared, also ultimately the zemuse x3 was also in tatters. The side of the zenmuse X3 was broke open and the inside was also smashed.

I am very devastated for this but i need closure as to why the drone downed because it was a major investment. I have extracted flight recorders and upload it onto Healthydrones.com upon my amateur analysis i see that the battery pack still have 19% charge in it (the last recorded charge), but upon closer inspection i found that the voltage in cell 1 have deviations and the deviations widen until there was only 2.7 V in cell 1 a deviation of 0.824 V (according to www.healthydrones.com). For your further analysis I have included the data in the .csv file for your analysis.

This is the data from the last flight of take off. The drone failed when it was on RTH function and was hovering right above the home location for landing, and then it stalled/shut down and fell from 114 feet/ 34.7 m (last recorded ascent).

From what i analyze the cell1 voltage deviated and had major deviation on the return back, this caused the battery to fail and ultimately lead to the demise of the drone mid RTH landing.

I need your opinions on this, is this what lead to the stall? Is it because the battery failed? If yes, is there anything i can do about it?

I need closure as to why the drone stalled, as well as i want to know whether my analysis is correct.

Thank you beforehand, guys.

Sorry for your crash.
Please get in touch with our tech support and send it in for fixing.
They will analyze the data and let you know what could have caused the issue.

Sorry to hear it - Battery management and its application to safe flying practice has been a topic of hot debate here and other discussion groups for a long time.
I hope you get it fixed and back into the air shortly.

After seeing the battery percentage drop to single figures (5 or 6%) in seconds from being in the mid 20's, a number of times I changed my procedures to land manually at a level of 30%.
I do not let the aircraft enter RTH from a battery level trigger. I just don't trust that function.

Without looking at the overall flight data from either the Go app or the aircraft directly, it would be difficult to determine for sure what could have caused the incident to occur. I recommend taking Mindy's advice to have the unit sent in for further evaluation. You would want to contact support@dji.com to get a RMA started.

Sorry to hear of your crash.
How many flights have been logged on that battery?
Do you deep cycle them every 10-15 charges?
I Always start off with 100% charge and land at 30% to 25%. Never lower than 25%.
Deep cycle frequently.
Too much at stake to take any chances.

DJI Mindy Posted at 2016-11-1 15:07
Sorry for your crash.
Please get in touch with our tech support and send it in for fixing.
They will ...

Hei Mindy, Thank you for the reply. where is the nearest DJI Official Service center?
I am located in Jakarta, Indonesia.

Farnk666 Posted at 2016-11-1 18:44
Sorry to hear it - Battery management and its application to safe flying practice has been a topic o ...

Yes, Thank you for your advice. I will take it into heart as i've learnt it the hard way.

Aeromirage Posted at 2016-11-2 05:11
Sorry to hear of your crash.
How many flights have been logged on that battery?
Do you deep cycle t ...

I have logged 9 charge on the battery. have not even reached the 10-15 charges you recommend. yes, I learnt that the hard way, no below 25% flight.

  I'm sorry to hear about your crash. My advice would be to never take off with less than 100% charge. I have lost count of how many instances of "battery failure" that I have seen where people have taken off with 60, 80, 97% and the Inspire has dropped out of the sky.

This is quite well documented in these forums, Google something like "inspire 1 takeoff with less than 100%". Maybe DJI should make more of an effort to ensure all Inspire pilots are aware of this.

I'm not sure what is written in the manuals these days but warnings like this should be on page 1. Doesn't help much when people don't read the manual though.

Good luck with the repairs

Mark G.

disastrousflier Posted at 2016-11-2 10:58
Hei Mindy, Thank you for the reply. where is the nearest DJI Official Service center?
I am located ...

Like I mentioned in post#4, you could email support@dji.com. In addition, you can look at Thor's post to see if any of the Support Phone lines work for you as well:

http://forum.dji.com/thread-67496-1-1.html

Aeromirage Posted at 2016-11-2 06:11
Sorry to hear of your crash.
How many flights have been logged on that battery?
Do you deep cycle t ...

What's the procedure for deep cycle?
Thanks

Aeromirage Posted at 2016-11-2 06:11
Sorry to hear of your crash.
How many flights have been logged on that battery?
Do you deep cycle t ...

What's the procedure for deep cycle?
Thanks

filmalaska Posted at 2016-11-3 02:04
What's the procedure for deep cycle?
Thanks

Charge the batt to 100%. Run the battery down till 15% and at 15%, make sure you're close to the aircraft. Hover the aircraft with the legs down until you see v3.3 on the top right corner of the app. Do this on a soft ground, grass is fine. At 10% the aircraft will want to land, keep holding the throttle up to avoid this. Keep the throttle up until you see 3.3v and then land. Turn off the batt, and you're done. Some people just land at 3.3v and allow the batt to completely shut itself off. I only do this if there is something seriously wrong with the batt. My one batt gave me a broken cell error, which was a false reading. So I deep cycled it to 3.3v and allowed the batt to turn itself off. Ever since then, I haven't seen that error no more.

Cabralkev Posted at 2016-11-3 05:52
Charge the batt to 100%. Run the battery down till 15% and at 15%, make sure you're close to the a ...

I do it this way also , works great .  I guess great minds think alike !

donnie

Thank you!

Cabralkev Posted at 2016-11-3 18:52
Charge the batt to 100%. Run the battery down till 15% and at 15%, make sure you're close to the a ...

Yep, this is sound advice - exactly what I do with my batts and the general consensus here amongst us old timers...

I never fly with my battery that low. Never had any issues. I get nervous as soon as I hear the 30% warning. I always bring it down immediately. I've also never used RTH in the 4 months that I've owned my inspire 1.