Disaster struck today - drone fell from sky

[russianfront]

Vortex ring state:

https://www.youtube.com/watch?v=tsd_x1i_vAA

My Phantom did not wobble like this before it fell. Don't think this was the cause of my crash.

 

[robinb]

But it did not power off. The video is still recording.
It had a motor shut down.

 

[BlackTracer]

Since the OP was full left stick down, it is possible this caused his motors to stop even though he wasn't on the ground. Here's how: the barometric sensor fails for whatever reason at that moment. If the sensed altitude is frozen at any value for the required interval, it's motors off.

 

[msinger]

the barometric sensor fails for whatever reason at that moment. If the sensed altitude is frozen at any value for the required interval, it's motors off.

That's an interesting theory. Do we know if the OP had the left stick the whole way down?

When I descend, I never hold the left stick the whole way down. I tried and found it causes my Phantom to wobble because it descends too quickly. (Queue the vortex ring state song.)

 

[PsychopathRC]

https://www.youtube.com/watch?v=qQjnfm5BGPQ

Near the beginning you see the drone, video'd from the ground, rise up then just fall. The part at the end of the video where the drone shuts down and falls to the ground almost hitting a guy reminds me very much of what happened to mine. Watch how fast it drops!

This is one of the scariest videos to watch if you are a Phantom owner. Should be required viewing for overconfident pilots.

Seen this and as stupid as it is, it's funny.

It's been mentioned that maybe the user in that video didn't have some 'intelligent' control switched on in the assistant software. For some reason, you can set the Phantom to shut down should it have a connection issue. Not sure why you'd want to do it. But maybe he had this option on.

 

[russianfront]

the barometric sensor fails for whatever reason at that moment. If the sensed altitude is frozen at any value for the required interval, it's motors off.

That's an interesting theory. Do we know if the OP had the left stick the whole way down?

When I descend, I never hold the left stick the whole way down. I tried and found it causes my Phantom to wobble because it descends too quickly. (Queue the vortex ring state song.)

Yes stick was all the way down. I was bringing it back to me in a hurry.

 

[justin00]

Few other people in help section reporting sane issue.. All v3 owners.

Frank thats wierd. If i land and dont touch throttle it might rev up.. but thats common due to it wanting to hover or something.. but ya for me left down will bring revs down if raised.. or at idle will shut off motors. It does take 3-4 seconds though.

 

[weston.d]

Re: 'Skyfalls' of Phantoms

I've had at least 4 episodes of my Phantom Vision 2 suddenly dropping out of the sky. (Skyfall)
Seems no help coming from DJI on the subject as far as my researches go.
My 'present' thoughts on the subject after doing my best to come to grips with the cause and having
actually predicted the last fall from grace I'm thinking it is fundamentally a battery problem.
I my 4 cases it happens at about the 12 min mark and about 40% battery left indication. The battery
to me appears to have decided it can no longer quite give enough power to stay aloft, accompanied by loss of connection,
and the craft can only go into skyfall.
While things happen suddenly I have been able to observe that there is an indication of a recovery
automatically and I have also managed a partial recovery with the joystick which has slowed the
drop I think and I've only had minor damage, blade tips/protectors.
The battery only needs to shut down or loose most of it's power for a fraction of a second to cause
a skyfall. I guess if that occurs it makes sense that one would loose communication.

Is the battery auto shutting down, overheating or what?
It also could be that the Phantom is not getting the battery condition right?

After my last skyfall we took off again with 40% battery and as we predicted the flight would be short
if we were half right in that the battery was incapable at less than 40% indicated charge. We took of OK and after about
a minute the controls, especially the 'UP' stick became sluggish to gain altitude and shortly after impossible
to maintain flight so we had a 'soft' hard landing. We think the battery had recovered somewhat after
the recent skyfall enough for our predicted short flight which by then indicated 35% battery available.

I have two batteries, obtained when I purchased my Phantom and they have only been recharged 8 times
so the Assistant tells me. Both have been involved in the skyfalls following the same senario.
Another local Phantom flyer lost his craft exactly the same way and it is at the bottom of the the local
harbour having just missed landfall when it dropped out of the sky. Not funny, but the silence from
DJI on any solution is deafening to say the least.

At this time, when I get some confidence back, I'll limit any flying to 10 mins on any one full battery charge.

INDIGO

 

[Meta4]

weston.d your guess about the battery doesn't really fit with my observations of how these things work.
Are you aware of vortex ring state? A lot of your description suggests that this might be what you are experiencing.
You mention protectors? If you are flying with prop guards, these can contribute to VRS and in general they seem to cause more problems than the prevent.

 

[justin00]

Where about is the pressure ? Any one have any pics ?
Just curious is all.. Cause I have been looking through the source code and for the altitude it keeps referring to the GPS..

However..... when I have 0 satellites I still have an altitude read out, which leads me to think there must be the pressure sensor or something.

 

[robinb]

I think its inside the nasa flight controller.

 

[Meta4]

GPS is much less accurate for altitude than for 2D positioning.
The Phantom ignores the GPS altitude and uses a barometric altimeter incorporated in the Naza flight controller.

 

[justin00]

Ah ok So the actual sensor probe is inside the naza ?
Ok cool, thanks for that. No wonder I couldnt find anything.. I was expecting to see a little tube or something

 

[robinb]

on another forum someone had disected one and put up pictures.

 

[eyecon82]

Mine almost fell out of the sky yesterday. V3 here. DJI Phantom 2 Vision+ Flips upside down and does …: http://youtu.be/ogExIuRQHC0

 

[moto phantom]

Mine almost fell out of the sky yesterday. V3 here. DJI Phantom 2 Vision+ Flips upside down and does …: http://youtu.be/ogExIuRQHC0

Scary, I didn't use to fear flying my quad, I need to stop reading these forums. Pretty soon instead of flying it, I will just hold it and dream of the good ol days.

 

[justin00]

Take the top off the shell off.... we can look for similarites with Frank and DBS.

It wont void warranty, no one will no you have done it :]

 

[russianfront]

I'm starting to think these things are nothing more than fancy Chinese flying junk. The stoke that I felt in the first few days has given away to a feeling of dread over using these things in cities with people and expensive property everywhere. Amazon recieved my broken DJI today. Fingers crossed that I'll get a quick refund.

 

[eyecon82]

Repost

 

[russianfront]

Got my full refund today from Amazon!
Chain of events:
- Phantom crashed Dec. 19th
- Packed up and send back to Amazon (using their pre-paid return shipping via UPS) on Dec. 20th
- Arrived back to Amazon at their returns centre in Las Vegas Dec. 29th (slow shipping speed due to holidays)
- Full refund Dec. 30th

Cheers to Amazon - I wouldn't buy anywhere else!!

I hope my steaming pile of DJI crap is shipped back to them to examine and fume over!

Going to pull the trigger on another one in a day or so. Next time I'm going to document the hell out of my flights: 1) Phone screen recording 2) Gopro on my head 3) Run on-board video more often - so that if I have another crash I have some proof.