Argh flyaway on 4th flight

[scotsman]

All going swimmingly, perfect flying and excellent footage with a Hero 3+ and H3-3D gimbal in rural scotland. All controls still at default. 3rd flight had a collision with a tree when it started to slide to the side (although most probably pilot error). Swapped to fresh set of propellers after I noticed a bit of a wobble and sliding around after the crash, and calibrated the compass.

4th flight, got the green light, up we go. Did notice it wasn't as stable as it used to be, but continued anyway. Went to about 40m up. Not really holding it's position that well, and turning left caused it to go in a circle. Suddenly at high speed it takes off North West over the treetops. I kill the controller hoping for failsafe but it just keeps going out of sight.

Haven't found it yet

Why oh why? These things have a life of their own. Very disappointed.

This is when I wish it had some sort of way to find it...

 

[IrishSights]

You flying it into a tree just may have had something to do with it. Sorry for your loss just the same. After a crash or even a hard landing it is best not to fly again until you have checked over the whole craft including looking at it via the Assistant software. All very well in hindsight. However please do not blame your Phantom, when it all falls at your feet.

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[scotsman]

Good advice. I did give it a thorough visual check, including all motors. What would the assistant software have told me?

 

[ianwood]

Most definitely it was from the crash. At minimum, the IMU needs an advanced calibration after a crash. Or it could have been mechanical damage to one of the motors. Generally you need to give a pretty thorough look through, motor binding, open it up, look for cracks, loose solder joints, etc.

 

[laselvasurf]

All going swimmingly, perfect flying and excellent footage with a Hero 3+ and H3-3D gimbal in rural scotland. All controls still at default. 3rd flight had a collision with a tree when it started to slide to the side (although most probably pilot error). Swapped to fresh set of propellers after I noticed a bit of a wobble and sliding around after the crash, and calibrated the compass.

4th flight, got the green light, up we go. Did notice it wasn't as stable as it used to be, but continued anyway. Went to about 40m up. Not really holding it's position that well, and turning left caused it to go in a circle. Suddenly at high speed it takes off North West over the treetops. I kill the controller hoping for failsafe but it just keeps going out of sight.

Haven't found it yet

Why oh why? These things have a life of their own. Very disappointed.

This is when I wish it had some sort of way to find it...

Sorry for the loss. However, I wouldn't say this was a flyaways and you shouldn't be disappointed... The crash certainly caused the issue, when those kinds of abrupt things happen, it can throw the IMU way out of whack. I've seen way to many "flyaways" that are really just user error, or lack of experience(like this scenario) that give DJI a bad name and it's a bit frustrating. I have 300+ flights on the NAZA platform and have never had an issue.

 

[scotsman]

give DJI a bad name and it's a bit frustrating

I have no doubt that the platform is a good one, and it's clear that my inexperience probably caused the issue. However having read the Phantom 2 user manual cover to cover there is no mention of when you should recalibrate the IMU or even what recalibration is for.

It would be nice to have a section "What to do if your Phantom crashes", or at the very least a troubleshooting guide. I am sure that that information is online somewhere with some grazing through forums etc. but I was out in the field with no internet.

In short, product great. Information, not so. And ultimately it caused me to lose my phantom + gopro.

 

[IrishSights]

...In short, product great. Information, not so. And ultimately it caused me to lose my phantom + gopro.

Sorry, you are in denial. Ultimately it was the pilot that caused this Phantom to be lost, blaming documentation or lack of it is not an excuse. Having said that we all know the documentation could be better.

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[Khudson7]

I have learned much more by reading forums like this and from the many experienced flyers here. I agree, the documentation sucks! But so far, after 4 months of heavy duty flying,(hey, I am retired so what else is there to do), I have had no problems.

 

[KBurn]

I experienced something similar but managed to save the P2. Was flying over a canal in Norway and seemed to have a slight drift. Was not paying attention to satellite lock or GPS mode as I was fairly new. Suddenly, my P2 took off and flew away over the roofs! My instant reaction was to send the P2 up as fast as I could! At some point the GPS probably kicked in again and held it's location while just rising.... incredibly scary.

Was there a breeze when you were flying? If so, when the GPS is inactive and you are in ATTI mode, a huge gust (over trees for example) can send your P2 flying suddenly! The crash could have loosened the connection to the GPS unit. The plug is fairly feeble... I suspect so many flyaway cases are actually situations when the P2 is blown away with GPS inactive...

 

[Happyflyer]

A real bummer on your fourth flight. IF you replace the quad be sure you put a reward sticker with phone number and a tracker. It just could help you find it.

 

[Mike]

I've had my P2 for a few months now and experienced the same behavior for the first time the other day. Calibrated and all greens with 9 satellites. Took off in GPS mode and got about 30m up and it suddenly took off like a rocket to the right. I had never seen it roll that far in any direction. I slammed the stick to the left with no change at all to the flight direction. I flipped the switch to FS but got zero response. My heart was pounding now as I'm watching it tear off over open water. I flipped the switch to ATT and finally was able to regain control. It was essentially responding like it was in manual mode at this point. I was able to bring it back and land it. I did a recalibration, powered off and on and recalibrated again followed by another power cycle. I relaunched and hovered about 15 feet up for a little while slowly moving it back and forth in different directions. Everything seemed fine again. I took it up a little higher and headed out slowly, shooting straight down. About 3 minutes later I centered the right stick but it kept heading off in the direction it was previously flying. I flipped into ATT mode and got it back. At this point I noticed that my GPS was bouncing back and forth between 12 and 0 satellites. I landed it and took it back to investigate. Assistant software said GPS needed to be recalibrated. I did and everything looked good in the software. I took it apart and checked the connections. Everything seemed fine. Took it back out and it was flashing red/yellow. I did calibration, got green. Powered it off and on and it was back to red/yellow again. It took 3 more tries before it stayed green on power up. Took it up and flew 2 batteries with zero issues. Went back out a few hours later, calibrated, took it up and it immediately took off with a mind of it's own. Can anyone shed any light on what is causing this behavior?

 

[IrishSights]

Hi Mike, Had you had any crash or hard landings? Was the compass reading high before you did recalabration? - I presume you mean IMU recalibration. Was there any pop-up warnings in the Assistant software? One thing you could do is degauss the compass. It could also be a faulty/dry solder joint in GPS? As you can get it back using ATTI mode it does point to the GPS. Just my pennies worth.

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[EMCSQUAR]

I agree w/Irish, sounds like compass needs to be deaussed. Run an advanced IMU calibration & note compass #s (should be between 1200 - 1800) Also note where you were flying it - was it near a residential area? Or near heavy metallic objects? Could have been an RF issue. Another note - what version of assistant are you using? Recently DJI revised the MAC version for NAZA V2 because the IMU calibration was giving false readings, the new version has cured that.

What I'd do, just to get a ground zero starting point - go into assistant -> tools -> perform an advanced IMU calibration, then go to basic - RC and recalibrate your sticks, then do compass calibration.

 

[Mike]

Had you had any crash or hard landings? Was the compass reading high before you did recalabration? - I presume you mean IMU recalibration. Was there any pop-up warnings in the Assistant software? One thing you could do is degauss the compass. It could also be a faulty/dry solder joint in GPS? As you can get it back using ATTI mode it does point to the GPS.

No crashes or hard landings at all. I had just been at the beach for a week in Jekyll Island flying with no problems. It did take a plane ride to Chicago though. I didn't check the compass readings when in the assistant software. I wouldn't have known what was normal anyway. Now that I'm back home, I've had time to research and know what they should be. At the time, there was a popup warning that the GPS needed to be calibrated or there was magnetic interference. I did a compass calibration and the error disappeared. Now that I'm back home, I've checked the assistant again and the compass Mod is around 1500 which is in the normal range isn't it? When I calibrated in the field, I got the "success" lights and then took off. What I don't understand is why it would tear off in a direction at high speed and not respond to the stick commands. Could a compass error cause that kind of behavior?

 

[Mike]

I agree w/Irish, sounds like compass needs to be deaussed. Run an advanced IMU calibration & note compass #s (should be between 1200 - 1800) Also note where you were flying it - was it near a residential area? Or near heavy metallic objects? Could have been an RF issue. Another note - what version of assistant are you using? Recently DJI revised the MAC version for NAZA V2 because the IMU calibration was giving false readings, the new version has cured that.

What I'd do, just to get a ground zero starting point - go into assistant -> tools -> perform an advanced IMU calibration, then go to basic - RC and recalibrate your sticks, then do compass calibration.

OK, I'm back home now. Assistant shows my compass Mod around 1500. I've run an advanced IMU cal, sticks cal and compass cal. I haven't yet had an opportunity to take it out for a test (too many obstacles in the neighborhood). There must have been some magnetic interference where I was because of the need to recalibrate the compass all the time. But would that cause the behavior I observed? Why would I lose complete control unless in Atti mode? And why would the OSD show the satellites bouncing between 12 and 0? I'm afraid that maybe something with GPS is amiss? That would explain why RTH didn't work and no control in GPS mode. Is there a way to check the GPS?