Long story short, I was flying my drone today like any other, no errors reported in the app when taking off or at the time of the crash. I took my drone on the same route I always do and had no issues with flight. I was looking at the app at the time to see where i was until i saw the spinning blurred live feed that i always see in drone crash videos. I looked up into the sky and it was gone. Thankfully the app recorded the last point and lead me right to the tree that it was stuck in. The people who lived in the house with the tree were very nice and helped me get the drone down.
I went back home and did a full inspection of the drone. No visible cracks, no errors reported in the app, gimbal working normally, but only 3 of the 4 props spun up properly. the 4th motor only spun slowly and the blade was spinning off balance causing visible shaking. I replaced all 4 props and the same issue still stayed. Since these motors are metal, i'm assuming the 4th motor was the point of impact. The motor will need replacing.
With all that out of the way, I want to know what happened here. What caused my drone to fall out of the sky when nothing seemed abnormal pre-takeoff or in flight? The drone will live for some more flights but i want to make sure this doesn't happen again. Someone explain to me what happened.
Here is my healthydrones report: http://healthydrones.com/main?share=Mjk1NQ

Hi dg8882, can you tell us how old the battery is and, did you have any problems putting the battery in or taking it out?

connorschulte@g Posted at 2016-3-19 16:30
Hi dg8882, can you tell us how old the battery is and, did you have any problems putting the battery ...

The battery was supplied with my drone that i bought from a retailer a bit over a month ago. It's reported life in the DJI app is 93%. I have had no issues with putting in or taking out the battery.

At the beginning, it ooks like you lost satellites in the first few seconds and the Phantom switched to ATTI mode. At the end before the crash, you lost the compass. Did you calibrate the compass before flight?

Take a look at your tablet or phone and play back the flight.

Found rate of change in the compass of 25 degrees or more per 0.1 seconds.
That's about a 90 degree turn in a third of a second, which is not normal.

This can be a result of extremely strong winds, a crash into an object or a bad compass.

        Flight time        Altitude        Home Distance        Compass Turn
Rate Per 0.1s
A        03m 00s        244.4 ft           2,147 ft        25.8
B        03m 01s        238.8 ft           2,160 ft        35.0
C        03m 01s        229.7 ft           2,167 ft        58.2
D        03m 02s        217.8 ft           2,170 ft        82.4
E        03m 02s        205.1 ft           2,174 ft        95.6
F        03m 03s        192.6 ft           2,178 ft        108.7
G        03m 03s        179.8 ft           2,180 ft        114.9
H        03m 04s        166.0 ft           2,180 ft        118.6
I        03m 04s        150.6 ft           2,180 ft        125.8

could it be the motor failed, and the damage was not done on impact with the tree?

He was at 244 ft so I doubt there are trees that tall in that area.

show us the clip and the flight path from your records. that might help us have a better understanding of what actually happened.

HealthyDrones analysis doesn't show much at all.
It doesn't show that you "lost compass" either and there's no GPS issues.
The compass indications HD reports are the Phantom spinning as it goes down - not a compass problem at all.
BTW .. compass or GPS issues wouldn't explain falling from the sky.
Suggestions that you didn't fit the battery properly or compass calibration might be a factor can probably be ignored too.
It shows that you had a normal flight for 665 metres and then your Phantom spun as it fell from the sky almost vertical.
You had minor cell voltage deviations on one cell but probably not enough to cause a problem.
The full flight data from inside the Phantom may show the full story and perhaps it will show that you lost one motor in flight.
The symptoms you noted for one motor may not be due to impact at all.
Are there any signs of impact damage?
If it was motor trouble, it could be the motor itself or the ESC that controls the motor.

my first instinct is that they motor failed,  I've only been flying a phantom for any 2 weeks, but have tons of rc experience and thing fall and break all the time

labroides@yahoo Posted at 2016-3-19 17:56
HealthyDrones analysis doesn't show much at all.
It doesn't show that you "lost compass" either and  ...

Are you sure that the motor was not damaged by the fall?
Starting it up afterwards, the motor is causing the arm to vibrate and is clearly off balance based on how the painted end of the prop is not staying level. I KNOW the motor was not like that before.

Here is the internal log if anyone needs it: https://drive.google.com/file/d/0B8OzG9t-xs5wNE5uWTdIQ19NZWM/view

dg8882 Posted at 2016-3-20 09:27
Are you sure that the motor was not damaged by the fall?
Starting it up afterwards, the motor is c ...

Were any of the props missing or broken when you found the aircraft?

Well just picturing how the drone fell in my head, say that the motor having problems did fail while in the air. now the other 3 would keep spinning. that would cause the drone to become unbalanced in the air and leave the unpowered corner to be falling. The unpowered corner would be pointing downwards since the other 3 are trying to rebalance the drone but can't since it is relying on the unpowered corner to provide lift. That puts that corner as direct point of impact. Since there is no significant marks on the drone body, i think it fell on a prop and that bent the motor threads.

I know that was a really bad explained theory but it could be possible..  The motor also spins freely by hand just like the others do, so that confuses me why it wouldn't run the same way. But i guess that supports a motor failure.

Geebax Posted at 2016-3-19 18:39
Were any of the props missing or broken when you found the aircraft?

All props were in tact and attached when i found it. But the prop of the problem motor did have significantly more dirt on it.

dg8882 Posted at 2016-3-20 09:51
All props were in tact and attached when i found it. But the prop of the problem motor did have si ...

Hmm, I wonder if the impact bent the prop shaft?

Geebax Posted at 2016-3-19 18:57
Hmm, I wonder if the impact bent the prop shaft?

Yes, that's my theory. The failed motor caused it to be the point of impact and it landed on a prop that bend the shaft.

dg8882 Posted at 2016-3-19 17:39
Well just picturing how the drone fell in my head, say that the motor having problems did fail while ...

I know little about ESCs, but if the motor turns freely (same as the others) when unpowered, I would really be suspicious of the ESC for that motor.  If you can have the patience to deal with them, I'm guessing DJI will take care of this whole thing under warranty, as they should.   You'll have to jump through the hoops, etc., but I'm guessing they'll come through.

AG0N-Gary Posted at 2016-3-19 22:57
I know little about ESCs, but if the motor turns freely (same as the others) when unpowered, I wou ...

Is it possible to test the ESC? For example, attach another motor to those terminals to see if it acts the same way?

dg8882 Posted at 2016-3-20 09:36
Is it possible to test the ESC? For example, attach another motor to those terminals to see if it  ...

Don't know why not.  Motors aren't too expensive.  You could get another and try it.  Order the right motor though.  It will require surgery though.

How old is your drone? Have you contacted DJI and got them to analyse the logs. They are the real experts after all and if it's under a year it will still have warranty for motor failure.

i had the same thing happen to me 58 seconds in to a flight it just veered left i knew there was no saving it so i just let go of the controllers i had shell damage and gimble damage ive sent it back to dji for repair with all my flight logs and information so they will see it wasnt my fauly i was 150ft up and she dropped like a stone im gutted to say the least when i took off the motors or one of the motors didnt have that natural hum with its hovvering i didnt pass any heed on this as im a newbie but from what i recall im putting it down to motor malfunction.now i just have to wait for it to come back new or repaired the weather has been great here the last week and im missing some major flying time

it probably wast weak GPS signal.

Well thank you everyone for the help but I have just submitted my RMA request to DJI.

I could order a motor and put it in and be back in the air but I am only 15 so costs are a huge issue for me. Since there is still that chance an ESC issue brought the drone down, I can't afford a new main board after voiding the warranty by putting in a new motor by myself. I'm really hoping just the motor is the problem but i'm going to let DJI take care of it if there is any bigger cause to the crash. Hopefully DJI does not try to fight me and i can get the drone in the mail by Tuesday or Wednesday and back in a couple weeks.

Assuming DJI gets hold of the drone by next Monday, how long can i expect it to be out?
Also, i have a modified controller. Is that going to screw the warranty for my drone? I know it already has for the controller. Can i get away with just not sending the controller?

andrewa Posted at 2016-3-20 14:14
it probably wast weak GPS signal.

Well if it was a GPS issue, the drone would just switch to atti mode and hover. GPS signal does not directly control the motors or any sensors.

labroides@yahoo Posted at 2016-3-19 14:56
HealthyDrones analysis doesn't show much at all.
It doesn't show that you "lost compass" either and  ...

An analysis of this flight using the .DAT file can be found here http://www.phantompilots.com/thr ... /page-2#post-725794

Sounds like either a bad motor or a bird strike to me...