Normal flight as usual. Prepare for landing. When the Phantom reached about 1 meter height, It suddenly flipped over and crashed. It was on GPS Mode. Don't know the reason why .  Any ideas ?

Interesting the battery came out @ 0:27.  based on this I would guess it was not in tightly and you lost power.  Either that or the old ESC problem.

acenothing Posted at 2015-4-24 01:00
Interesting the battery came out @ 0:27.  based on this I would guess it was not in tightly and you  ...

It looks to me that the battery came out after the initial impact.  Either way, it stinks.  I have only seen that flip in one other video and that was not a Phantom.  I wish I knew what caused it because then I could avoid it.

Battery was tightly installed. This phantom was about 2 month old.

I guess,  a video of similar issue that i've seen on youtube

Any chance you might have initiated the CSC command?
I know sometimes landing as you are descending and trying to yaw/turn a bit and may be trying to roll a bit left or right your sticks could end up unfortunately in the dreaded CSC position if not being careful...

Based on the topography, and that wind is blowing to the right in the video and that the copter went sharply right, could a strong and abrupt gust of wind have caught it?

By topography, I mean you're on a road which has valleys to each side.  So wind is going up the hill from the left, then back down again to the right.  I'm suggesting it could have had an updraft on the left side with a simultaneous downdraft on the right.  All of this could be coupled with ground effects or a partial vortex ring state as you approach.

Does it fly normally since this incident?

I'm afraid, the wind was not that strong ( around 8 to 12 km/h ). And I think there was a little chance to initiate the CSC command during flight. I'm using V2 controller with the lock mechanicsim at the end of the throttle stick.   The shell and the gimbal was broken. I would test it again after repairs.  

Jason WAI Posted at 2015-4-24 01:24
Battery was tightly installed. This phantom was about 2 month old.

I guess,  a video of similar is ...

The second video you post could have been because of the wind. Sounds like the wind is really blowing hard. Also he asked what leds are flashing and the kid said yellow he then said no GPS then.

Looks like you were trying to land near the curb of the road.

It is possible that the downflow of air from the Phantom rotors hit the curb and created a vortex causing the flip.

danrok Posted at 2015-4-25 06:20
Looks like you were trying to land near the curb of the road.

It is possible that the downflow of a ...

I always land it this way without problem.  This is the first time for the unexpected flip over during landing.     

Youtube:  

Hi, I was just viewing your video and noticed that you flying on a peak, meaning a drop off both sides, I am a glider pilot and we avoid anything like this low down as there is something called curl over.The wind from the left when reaching the top just curls creating a down draft and roll over turbulance, it doesnt need to be windy to pluck your phantom from the sky and turn it over.

Jason WAI Posted at 2015-4-26 21:59
Youtube:  DJI Phantom 2 - Flight just before Unexpected Flip Over and Crash

Nice video, and good music....sounds like Jeff Beck?
Sorry about your bird..

mine did this several times which is why it is is the shop right now and i bought a second bird.  hopefully they fix it.

After repairs during the weekend, I tried to test the Phantom2 again and examine if the problem was solved or not.  Unfortunately, the same unexpected flip over was happened again in the 3rd flight of today.The Phantom2 Shell and H3-3D Gimbal Damping Unit Upper brackets were broken again. Footage of OSD Information was available this time.

iOSD Screen Shot of  the Unexpected flipover today

Strange, battery at 0.0%, velocity at 769300.9 m/s ???? Even though the camera is pointing the same direction, it shows home point at 167 degrees, then 131 degrees. Noticed in the video, battery shows 38%, then at the time it flips it is 0%.

I have long suspected that normal vibration can cause the battery to disconnect for an instant which is long enough to reset the main controller and/or CSCs. Really they need capacitors to hold a charge long enough to cover an brief loss of power and report the bad connection via a warning or alarm. I have been interested in battery connections since owning a Parrot Bebop. Parrot decided to have a wire connector clip onto the battery. This makes switching batteries a pain but has no vibration issues like the hard connection in a DJI drone. The reason the batteries are tight in the DJI drones is to attempt to make the connections safe from vibrations but even so it could still happen. You have two flat surfaces in contact with each other with heavy vibration between them. It is a tough engineering problem.

hmmm.. my p2v+ does not have two flat surfaces but actually two plunging male pins that go into female connector - very similar to a 120vac wall plug.  so vibration is no issue - it justs slides between the 2 female rubbing tight sides.  Now there is that little sensor thing with 2 pins spring loaded to flat surfaces and I have never tried to figure out what they do;  they do not provide the upto 30 amps of current flow tho.  perhaps if these come loose something bad might happen?

As for caps, I measured the resistance between plus and minus pins of my p2v+ the other day to let someone else know what normal is:  I was VERY impressed with the HUGE capacitance they have inside the unit!  took almost 5 sec to charge up those huge capacitors to get to the real 2k ohm resistance!  then swap ohmeter leads and take another 5 sec to discharge, go thru 0, and come back up to 2k resistance!  I never thought I saw caps that big inside!  

Now, if these are just the ones on the ESC boards, they will be of little value to help "ride thru" a instantaneous loose connection as they will be in the high current path.  But I cannot but assume they have similar large size caps on the control pcboards to ride thru any quick power loss.  But if they don't, then this can be a good reason why a quick battery disconnect shuts off motors or resets GPS home position to 0,0 out in the atlantic ocean and maybe a reason for some fly aways to the east (in the usa)....  lots of pure guessing here....

Now there is that little sensor thing with 2 pins spring loaded to flat surfaces and I have never tried to figure out what they do

Those 2 little push pins are for the smart battery sensors.

i sent the phantom2 to DJI.  

Jason WAI Posted at 2015-4-29 20:15
i sent the phantom2 to DJI.

Jason,
To me it looks like a warranty repair issue. Clearly a fatal hardware issue and may be the root cause of a lot of these problems. You have some pretty good evidence there in the video and the pictures to prove it.
Good luck.

yorlik Posted at 2015-4-29 09:01
hmmm.. my p2v+ does not have two flat surfaces but actually two plunging male pins that go into fema ...

those pins are the serial data connection to controller from smart battery circuit.

if those loose connection you have no battery, no matter about the 2 pins for power.

pretty much think these are source of many battery alarm issues and stop and drop crashes

With 15years experience in playing RC aircraft and helicopters, I think It was so strange to have a phantom crashed like this.

Today we received the parcel from DJI.  DJI Tech and Support department provides a very  good and professional service.   We are impressed with all DJI's support and their ability to handle the case.  Thanks DJI !

What did they have to say about it?