phantom vision fly away!

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well now i know what every1 means. so i flew my phantom at a park approx 10km away it was fine i got home and charged it went 2 fly it and it said it needed compass calibration so i did it flew it up and it was doing circles i keept it hovering above my house until it settled down and off i went flew it out about 1200ft then it. just went haywire off on a angle i tryed 2 gain controll but nothing i turned off the remote and waited by this stage i had no wifi connection. i waited 5 min it didnt cum home so i used the gps tracker went rite 2 the spot and no1 has seen it i asked a old lady str8 across the road who was doing her gardening and she didnt see it.im gonna put sum flyers around and hope 4 the best
 
Re: phantom fly away!

uncle fester said:
well now i know what every1 means. so i flew my phantom at a park approx 10km away it was fine i got home and charged it went 2 fly it and it said it needed compass calibration so i did it flew it up and it was doing circles i keept it hovering above my house until it settled down and off i went flew it out about 1200ft then it. just went haywire off on a angle i tryed 2 gain controll but nothing i turned off the remote and waited by this stage i had no wifi connection. i waited 5 min it didnt cum home so i used the gps tracker went rite 2 the spot and no1 has seen it i asked a old lady str8 across the road who was doing her gardening and she didnt see it.im gonna put sum flyers around and hope 4 the best

Was this a Vision?
 
yes! im so happy i just got it back! i quickly printed sum flyers and put them in all the mailboxes around the gps mark got a phone call half hour later turns out it was approx 200m away from where the gps said it was in a big tree they were getting drunk on the lawn and seen it crash into the tree they said it was going full noise when it hit.got a bit of damage the camera came rite off and pulled the guts outa the plug! ahhh.so i really dont know what to do now i thought dji would have fixed this problem! if i knew they didn't i wouldn't have brought the dam thing!.im thinking that the problem is in that lil compass has any1 heard of other dji copters with the proper round compass flying off?and plz evey1 put ure contact details on ure copter!!!!!
 

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Fester, glad you hot if back! Curious, and this was on upgraded v1.05 firmware? But it sounds like compass freakishness. When you did the "compass dance" anything strange nearby... metal, magnetism, power, RF, celfones? You know the drill. Or is there some strange new hidden issue lurking after our firmware upgrades?

iDrone
 
i havent updated anything i just been flying it how i got it outa the box ive flowin it over this same place around 40-50 times.i mite have 2 tie a teather 2 it next time just incase :s
 
Ohhh, then maybe you got bit by the "invalid battery" bug in the original firmware that forces an Auto Landing whenever the data contacts in the battery lose their connection. It makes the PV think it's outta' juice. Someone else posted about a fly away & landing, then I guess when the contacts reseated themselves it thought everything's ok except it hasn't heard from the TX, so it initiates a takeoff (20m) then tries to GoHome.

iDrone
 
I've noticed doing a CSC to start the motors works fine, but not for shutting them down... if I'm off on one stick by just a bit, it'll shift power to the motors and begin to tilt/flip a little. So instead, I pull the throttle (left stick) all the way down & hold it for a couple extra seconds, and the motors shutdown together. No more flipping.

Re: fly-aways reported on this forum, so far they mostly seem to happen to PV's running out-of-box firmware with the "invalid battery" issue (corrected in v1.05 firmware Nov 18), the rest seem to be related to compass calibrations done just before the fly-away events. I dunno.

iDrone
 
iDrone said:
I've noticed doing a CSC to start the motors works fine, but not for shutting them down... if I'm off on one stick by just a bit, it'll shift power to the motors and begin to tilt/flip a little. So instead, I pull the throttle (left stick) all the way down & hold it for a couple extra seconds, and the motors shutdown together. No more flipping.
iDrone
After running the battery down on my first flight practicing takeoffs, hovering and landings (all perfect, amazing how easy it is to fly) I used CSC to shut off motors and it tilted onto 2 props on concrete (no damage). I later tried it on the bench and every time I used CSC to shut motors down some motors would rev up for a second. When holding throttle down it would never rev up and after 3 seconds motors would all shut down. Been using throttle down since then and never had it tip again.
 
AHill said:
iDrone said:
I've noticed doing a CSC to start the motors works fine, but not for shutting them down... if I'm off on one stick by just a bit, it'll shift power to the motors and begin to tilt/flip a little. So instead, I pull the throttle (left stick) all the way down & hold it for a couple extra seconds, and the motors shutdown together. No more flipping.
iDrone
After running the battery down on my first flight practicing takeoffs, hovering and landings (all perfect, amazing how easy it is to fly) I used CSC to shut off motors and it tilted onto 2 props on concrete (no damage). I later tried it on the bench and every time I used CSC to shut motors down some motors would rev up for a second. When holding throttle down it would never rev up and after 3 seconds motors would all shut down. Been using throttle down since then and never had it tip again.


X3
 
I've also experienced a suspected flyaway with my Phantom Vision. First day that it arrived we followed the youtube instructions and quick start guide ardently and flew in a large park, a long distance from any significant buildings. We flew cautiously and noted the aircraft having some trouble adjusting to wind gusts.

According to the Australian Bureau of Meteorology the winds were 20-28km/p/h SW at the closest monitoring station (an airport).

Nonetheless, problems were limited to it adjusting to face the wind before stabilising and being able to roughly hold its position while flying in the out of the box GPS mode.

The next day we took the drone to a smaller park (2 soccer fields). During startup, when activating the compass calibration mode the LEDs went straight to flashing green, indicating good to go. We took off, noticed more difficulty with the wind, including some drift off location, and so we flew it cautiously again. Winds observations were 19-24 when we began and heading towards the next observation of 28-43km/p/h when the flyaway occurred. The aircraft appeared to have significant trouble handling them, and my friend who was piloting began to bring it down from a height of about 15m ... when:

1. The drone turned 150 degrees
2. Nosed down
3. Flew at full pace in one direction
4. My friend tried to control it for a few seconds
5. Then when it appeared to be unresponsive let go of the sticks
6. The aircraft continued for the width of a soccer field
7. Struck a palm tree at ~8.5m
8. Battery ejected & Camera disconnected

The differences between this flight and the other:

1. I updated the controller, camera & aircraft firmware to the latest as of 21 November
2. Winds were stronger, aircraft had observable trouble with wind
3. 2 lines of houses starting approximately 50m from the aircraft when problems began
4. Drone did not require compass calibration
5. Controller AA batteries had been used for 1x 20 minute flight (other batteries fully charged)

The current status of the drone (after knocking it down from the tree with a long piece of wood):

1. 1x propeller cracked and chipped
2. 1x motor detached from inside wiring, holds in place with its own magnets but can be removed again with difficulty
3. 1x battery still in tree
4. A mysterious small rattle when shaking the drone
5. One corrupted video file (unviewable) of spectacular proportions

I'm not entirely sure how to proceed. I read in another thread that information from the app can be used to analyse what went wrong. I suppose I need to find that information and send it to DJI. Does anyone have any advice on how to proceed? I'm hooked and I already miss flying.
 
Hmmm, I'm a bit dumbfounded since you're running v1.05 firmware... perhaps there are more bugs to squash. If I'm not mistaken, there's an interesting pattern developing here. A few posts about fly-aways report that the aircraft suddenly initiated an angular descent, moving rapidly in a downward angle (nosedive) until striking a tree or crashing into the ground. This suggests one of the prop motors dropped speed, lost power, or stalled (culprit: wind gust?) Again I dunno, a deep mystery.

Could you tell us the significance of item #3: two lines of houses 50m away? Was this about powerlines adjacent to the houses? Or something else?

iDrone
 
from what i have seen and read about fly aways with the phantom.i have no doubt that thats what mine did. flying fine then all of a sudden took off full speed sideways until it hit a tree no doubt if it was higher it would have gone a long way! and wouldnt respond.i just flew it again now and it took me half an hour to calabrate the compass so sumthings goin on with it.ive put my contact details on it if it flys away again good riddens! i thought dji woulda sorted this out obviously they to bizzy playing ping pong!
 
iDrone

The reason I mentioned the houses is because I saw some people suggesting in other threads about original Phantom flyaways that they might be caused by radio interference.

At location #1 we were ~100m from High capacity power lines at the closest point, but had no problems.

At location #2 we were ~45m from powerlines and ~50m from the closest house at the point where the problem started.

What seriously concerns me is that with a full battery, the Phantom Vision can travel 15km at full speed (assuming full thrust doesn't drain faster than 25 minutes). This puts the drone within range of an airport, the sea, skyscrapers etc. if we continue using parks like the ones we're using. I want to be responsible, and I understand the complexity of the software involved here, as I am a programmer, but I can't see myself justifying flying again until I know I can stop this from occurring.

Does anyone know anything about the flight data storage and how I can possibly inspect it?

What precautions can I utilise? I've seen people mention switching to manual mode... I assume I can just down thrust when I do that to crash-land it.
 
If it's any consolation, I regularly fly near metal rooftops & metal high tension distribution towers... so far without incident. I've also seen several YouTube videos of Phantom Vision's flying over rural & industrial areas, complete w/metal rooftops, powerlines, cellular towers etc, again with w/o incident.

I had no idea there were so many videos of Phantom-1 fly aways on YouTube. After reading other forums & viewing many videos it's difficult to come to any definitive conclusions. But I've gotta say the following convinced me there was no pilot error involved;

http://youtu.be/JnDM7RIgJ5w
http://youtu.be/RCt-XluLyA0
http://youtu.be/CInwaLBlPxY

I could understand shorted windings in a motor, an ESC failing from a weak FET or cold solder joint, these would tilt the PV and 'tho the autopilot would try to compensate, it would no doubt make a diagonal descent into a tree, etc. But the fly aways where the aircraft is calmly hovering then suddenly takes off in a new direction sounds like it thinks it's in the wrong place, so it tries to "fly back" to the "proper" coordinates.

I'm only guessing here, but it sounds more like invalid GPS data, as the compass only provides the autopilot with a heading (0-360), but not the XY coordinates of where it should be. Else the compass is outputting erroneous data causing the autopilot to fly in the wrong direction to hover over your current XY coord, only to start flying it in the wrong direction and finding out the XY values are going backwards, run loop again... fly in direction indicated by compass, XY coord's don't improve, run loop again... I'm just blabbering out loud, trying to make sense of it. One piece of data that's missing from all this is whether or not the pilots performed a compass calibration prior to the runaway flight. If that's the case, there may be an issue with the compass calibration procedure maintaining the new calibration.

Very unsettling that Phantom-1's did this, and now many reports of Phantom Vision's doing the same thing as well. Between the RC community & DJI I certainly hope we get to the bottom of this soon.

iDrone
 
iDrone said:
I'm only guessing here, but it sounds more like invalid GPS data, as the compass only provides the autopilot with a heading (0-360), but not the XY coordinates of where it should be. Else the compass is outputting erroneous data causing the autopilot to fly in the wrong direction to hover over your current XY coord, only to start flying it in the wrong direction and finding out the XY values are going backwards, run loop again... fly in direction indicated by compass, XY coord's don't improve, run loop again... I'm just blabbering out loud, trying to make sense of it. One piece of data that's missing from all this is whether or not the pilots performed a compass calibration prior to the runaway flight. If that's the case, there may be an issue with the compass calibration procedure maintaining the new calibration.
iDrone

This scenario could cause a flyaway, but it's really automation 101 to make sure that conflicted compass / gyro / gps data does not cause a problem. I've worked writing code for autonomous devices - you just do not let this sort of thing happen. The only cause of a potential flyaway should not be code, but a total failure of 1 or more motors or motor controllers. Even in this case, the flight controller computer should attempt to make a controlled landing, or just cut the master power. Now if you have a design with single point of failure, ie no power cut off upstream of the motor controller, and a controller fails shorted on, then you have a problem. But you should never design anything like this without requiring multiple failures, ie reducing probability to a very low level.
 
Now that's something that would explain some of these lateral/diagonal fly-aways. I could see how if the screws that secure the motors got loose enough, or the plastic underneath them cracked or partially damaged, the motor might come loose mid-flight and we'd have a fly-away.

From looking at the bottom of the PV it looks like four 2mm hex screws hold each motor in place. Checking mine, all but one of them were tight. Just in case they used Loctite to secure them, I didn't want to press my luck - all I was looking for was loose screws, so if any of you decide to check I'd be very careful not to apply too much torque for fear of cinching the screws so tight they go right through the plastic bosses underneath them. In fact, I think what I might do is back that screw out, put a little bit of light Loctite on it and put it back in until it just turns finger tight.

[Edit: I stand corrected - don't use Loctite, it may melt the plastic!] (see comments further below)

iDrone
 
gpauk said:
This scenario could cause a flyaway, but it's really automation 101 to make sure that conflicted compass / gyro / gps data does not cause a problem. I've worked writing code for autonomous devices - you just do not let this sort of thing happen. The only cause of a potential flyaway should not be code, but a total failure of 1 or more motors or motor controllers. Even in this case, the flight controller computer should attempt to make a controlled landing, or just cut the master power. Now if you have a design with single point of failure, ie no power cut off upstream of the motor controller, and a controller fails shorted on, then you have a problem. But you should never design anything like this without requiring multiple failures, ie reducing probability to a very low level.

I think it would be fantastic to have a true fail-safe option. A switch that if activated would kill all power from the flight battery. A free-falling Phantom is safer IMO than a fly away. We would know that if it came down to it, we could end the flight, period. This would not help if the TX was responsible, but any other contingency would be covered.
 

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