Crazy fly away today! PH2

[Jeffro]

I'm sure someone can explain this but I sure can't.

I'm a rural flyer but this Phantom is so stable and predictable I had no issues flying it in the city for the first time today to get some video of my son's house.
Turned it on and let it orientate on a cement slab. Didn't turn the Gopro on at first because I was just going to fly it around for them for a bit.

Started it up, let it orientate in GPS mode. Got the total green and started it and let it idle. No problems. As soon as I started to power up the motors it went wide open went up and behind me so fast it wasn't funny. Tried every motion of both sticks in GPS with no response. It's fly fast to the south at what I'm guessing the "return to home height of 200ft." Switched to "Control Lock" tried both sticks no response.

I read an article that suggested that I may want to make the "ATT2" position "total manual" just in case the on board navigation was unresponsive so it could be over ridden and possibly stop a fly away. And I did that several days ago.

So I flipped it to ATT2 and it stopped it's fly away and I had some control. It was way up there and over a grocery store parking lot that honestly had every space filled. I started coaxing it back toward me and it seemed like it wanted to keep climbing although it was coming back with the right stick pulled back toward me. As I was getting a little uncomfortable with it climbing almost out of sight while it was coming back in my direction I tried switching to "GPS" and it took off like crazy away from me again. I then panicked and just shut the controller off hoping it would "RETURN TO HOME"

IT FELL STRAIGHT OUT OF THE SKY. When the controller was switched off. Tumbling straight down to a crowed parking lot. Switched it back on and it powered up righted itself and took back off away from me and the parking lot.(Thank GOD!)

Switched it back to ATTI 2 and it fell out of the sky tumbling end over end hitting a tree, and the ground. Broke the Gimbal clear off. I've only had it a week. I will get warranty but I'm scared to put my gopro (that is now scuffed up) on another one. Also today's liability issues over a full parking lot made me think twice. Has anyone heard of these taking off like this? Any imput on what to do would be greatly appreciated!! Thanks!

 

[Hughie]

Did you calibrate the compass before this flight ?

 

[paulajayne]

Cement slab?
Rebar in it?

 

[Fyod]

^ I have had some problems taking off from rebar cement slabs. Moved over 10 feet into some gravel and all was ok (restarted the bird).
This really does sound like a bad calibration or compass thrown way off by something.
Btw: it seems that metal structures don't throw the compass off after you've taken off. The main problem seems to be during startup. This is also why it is not recommended to take off from a car. You could take a laptop and check the IMU values at the spot you took off from, especially the "Mod" value. You can check it at home, maybe its still whack.

 

[Hughie]

I'm sure someone can explain this but I sure can't.

I'm a rural flyer but this Phantom is so stable and predictable I had no issues flying it in the city for the first time today to get some video of my son's house.
Turned it on and let it orientate on a cement slab. Didn't turn the Gopro on at first because I was just going to fly it around for them for a bit.

Started it up, let it orientate in GPS mode. Got the total green and started it and let it idle. No problems. As soon as I started to power up the motors it went wide open went up and behind me so fast it wasn't funny. Tried every motion of both sticks in GPS with no response. It's fly fast to the south at what I'm guessing the "return to home height of 200ft." Switched to "Control Lock" tried both sticks no response.

I read an article that suggested that I may want to make the "ATT2" position "total manual" just in case the on board navigation was unresponsive so it could be over ridden and possibly stop a fly away. And I did that several days ago.

So I flipped it to ATT2 and it stopped it's fly away and I had some control. It was way up there and over a grocery store parking lot that honestly had every space filled. I started coaxing it back toward me and it seemed like it wanted to keep climbing although it was coming back with the right stick pulled back toward me. As I was getting a little uncomfortable with it climbing almost out of sight while it was coming back in my direction I tried switching to "GPS" and it took off like crazy away from me again. I then panicked and just shut the controller off hoping it would "RETURN TO HOME"

IT FELL STRAIGHT OUT OF THE SKY. When the controller was switched off. Tumbling straight down to a crowed parking lot. Switched it back on and it powered up righted itself and took back off away from me and the parking lot.(Thank GOD!)

Switched it back to ATTI 2 and it fell out of the sky tumbling end over end hitting a tree, and the ground. Broke the Gimbal clear off. I've only had it a week. I will get warranty but I'm scared to put my gopro (that is now scuffed up) on another one. Also today's liability issues over a full parking lot made me think twice. Has anyone heard of these taking off like this? Any imput on what to do would be greatly appreciated!! Thanks!

There do seem to be two issues here. "Flyaway" and engine shut down.

As far as flyaway is concerned, as this appeared to be going through RTH phase, and because it stopped doing this when you switched out of GPS, I would suspect that the what the GPS believed its home point was, and what you thought it was, were different. How many sattelites did you get? If you have IOC selected, did you fly when the IOC lights when all green or did you wait for the second (homepoint) set of green flashed. This looks like Homepoint or compass to me. Did you calibrate the compass before this flight ?

Engine shut down. This is odd isnt it, and worrying from a liability angle. My only thought is that the IMU startup calibration (determining flight time initialisation values for 0 velocity/0 acceleration, 0 feet AGL!, may not have been done. If the quad thought that ground level was much higher than it really was and believed it has completed its return home and thought it had landed but at altitude, if you get my drift - it could have then shut the engines down as it believed it was "on the ground".

One other thing. I was interested as to why you did not attempt recovery using ATTI. You did not mention it anyway.

 

[Jeffro]

Thanks everyone for their thoughts on the matter!! I was afraid I would get dismissed as a novice nut!

I did not re-calibrate the compass. I let it go through it finding all the satellites and I thought it gave me the triple green meaning it was happy. I've flown it probably 50 times, I comfortable with that sequence. So if it gives me even more light sequences after that I've never seen them. (I had no reds)

I failed to say when it was still screaming away I believe I used ATTI 1 first and it did nothing to change it's course or speed. Atti 2 I had calibrated to "manual" mode which gained me some control.

I'm sure the cement had rebar in it to answer that question.

I agree there appears to be two separate problems here. I believe it thought "home" was somewhere else, and that was part of the problem. The next one is it appeared to just shut of when the controller was turned off.(In my attempt to make it return to where I thought home was) I feel it couldn't have been going to a "previous" home because I had never been in that direction before to make a home point over there. Good point Hughie if it thought it was sitting on the ground at that altitude maybe it did just go back to idle!

There is yet one other thing that I think does not come into play but I will mention it. I am using the upgraded DJI controller (with the camera wheel on the left top) it came with a sticking left stick. When you pull it down (to power down) it "Click's and sticks" and stays in that position. It actually has a little snap. They are suppose to be sending me another controller. All you have to do is touch it and it "clicks" and springs right back to neutral. I have gotten used to it and for my flying actions it didn't play a part in this mess as far as I can tell.


For the record I am very apprehensive to fly the new on in a public area. This flight was not suppose to be flying over people at all.

If someone thinks I did something wrong please tell me!! The only corrective action that I get so far that I will surely do is always re calibrate the compass when I go to a new location!

Thanks everyone for your help and Merry Christmas!!

Jeff from Illinois

 

[justin00]

Check the IMU as well, as others had suggested previously.

 

[crash1sttime]

I did not re-calibrate the compass. I let it go through it finding all the satellites and I thought it gave me the triple green meaning it was happy. (I had no reds

The unit wont show a request via light for compass calibration, unless its totally out of whack, however DJI do say that it should be done before every flight or if the take off point is signifigantly different to the original point.

Make it a habit, everytime do the calibration procedure, let it settle then flick the right switch up and down at least 6 times until the rear lights go yellow and then do the calibration dance.

 

[msinger]

DJI do say that it should be done before every flight or if the take off point is signifigantly different to the original point

The DJI manual only suggests calibrating the compass when the flight location changes. There is no need to do it before every flight. But, it wouldn't hurt anything if you do it every time.

 

[BWJ]

If you take the time to watch this, you can probably save some cash and sorrys https://www.youtube.com/watch?v=_ge3GuhEDRM

 

[MacCool]

There is yet one other thing that I think does not come into play but I will mention it. I am using the upgraded DJI controller (with the camera wheel on the left top) it came with a sticking left stick. When you pull it down (to power down) it "Click's and sticks" and stays in that position. It actually has a little snap. They are suppose to be sending me another controller. All you have to do is touch it and it "clicks" and springs right back to neutral. I have gotten used to it and for my flying actions it didn't play a part in this mess as far as I can tell.

The new transmitter is designed with a detent/lock at the bottom of the left stick. It's a "feature", designed so that you can manage a long descent by clicking the throttle all the way in the down position and it will stay there without you having to keep holding a spring-loaded stick back. Your transmitter is normal for the new model. They all do that. I agree, it doesn't likely come into play in this scenario. I'm not a particular fan of that "feature", but OTOH I've never had an RC transmitter where the throttle was spring-loaded either. You get used to it. I've read that that detent can be disabled.

You could postulate that there's some kind of a problem with the transmitter, and I suppose that's possible and that it needs replacing but my experience over many years of R/C is that transmitter failures are very, very rare. My suspicion is that, for whatever reason, you just plain lost GPS lock. Solar flare, cloud cover, blocked by buildings, faulty GPS module connection, inadequate shielding, whatever, I don't think your Phantom was getting the info it needed to fly in a controllable manner by GPS reference.

 

[Narrator]

Not sure if this is helpful.
I've noticed that two things greatly affect attention to detail - being accompanied by others, and a change of venue.
Both of these things have caused me to forget start-up procedures or think I've covered everything.
Having seen how easy these things distract, I'm now on alert for them.

 

[isky172]

If you're in manual mode and turn off the controller, wouldn't that essentially be a CSC action? (Personally, I don't know for sure - never tried it. I certainly won't be attempting it any time soon (on purpose, anyway))

 

[Jeffro]

Check the IMU as well, as others had suggested previously.

The IMU value's looked good, I did an advanced calibration again and it calibrated fine. Thanks

If you take the time to watch this, you can probably save some cash and sorrys https://www.youtube.com/watch?v=_ge3GuhEDRM

Good video. I feel a little better about this whole deal though as the gentleman that makes the video clearly imply's that there are issues with calibration and the way software interprets values that are out of the normal. With the new Phantom 2 that I hope I get I will take the extra time to calibrate the compass and move the Quad to get a more positive home point.

Thanks everyone for the help!

Jeff from Illinois

 

[Happyflyer]

Interesting video and it adds up as a good possibility. But problem can be checked with doing the short fly away from you and doing the Home Lock return routine. Do it in two directions and that will tell you if lock is at your location or as stated 14 miles away. Fly away problem solved.

 

[ianwood]

If you take the time to watch this, you can probably save some cash and sorrys https://www.youtube.com/watch?v=_ge3GuhEDRM

That video couldn't be more incorrect.

OP, if you have video of the incident, you should post it. Without video, it's just random guessing.

 

[MacCool]

That video couldn't be more incorrect.

Agreed. That guy has an imperfect understanding of GPS.

 

[BWJ]

Whats wrong with the video ? have you never noticed the gps issue on a cellphone

 

[sdtrojan]

Cement slab?
Rebar in it?

Noticed the same thing at a local park with a cement bench, was not getting any GPS showing on the OSD, but the phantom showed ready to fly by the lights. I moved it several feet away, powered down and re-powered the transmitter and Phantom again. 10 GPSs locked within seconds, no problem during flight.

 

[Jeffro]

I'm sorry I don't have any video of the incident. But there was no chance to do any type of short flying test as was suggested. As soon as it lifted off (Maybe 3 inches) it took off straight up and aggressively moving away. I am very sure that it gave me the fast green blinks along with the "only green" and "no red." For me that is too easy to miss, I'm positive I had the go ahead from the unit.