Drone ignored pull-back command = crashed

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I'm new to drones; not new to RC flight. This is my first Phantom.

Generally impressed, yet greatly concerned.

Plan: Slow approach and fly-over shot of a town clock in a park.
(one of those tall old-towne iron post-mounted clocks they put in parks)
Very calm day, almost no wind which was what convinced me to go fly..

The P4 was facing the Clock. When it started to get too close (At this point the Obstacle Avoidance was clearly not working) i did a 100% pull-back and away control command that was completely ignored by the aircraft until after the P4 made contact with the clock lens :mad:, where it then descended down the post to the concrete, where it decided to shoot-off backwards (full-vertical-tilt), into a concrete/brick wall which it bounced off of and tumbled over until finally tasting dirt and getting stuck. :oops:

I haven't figured out how to upload a flight log yet, but I did find it and carefully studied the timeline, commands and resulting flight. It clearly shows my CSC to pull-back and away, and shows the UAV completely ignoring the command, then losing control on contact. This was clearly a malfunction. I would be the first one to say it was my fault if I wasn't the one holding the controller, but I know I pulled back and I also know the aircraft didn't. It's not the first time I've made a CSC for the aircraft to move, and it ignored the command - I figured it was something I did, since it didn't happen again, until this incident.

No one was harmed; no property (other than the aircraft and my dignity) was damaged.

The battery ejected (i presume once it hit the wall) which was found only 3 feet from the LZ.

Two props were trashed, the others might make good spares at best.

The body sustained permanent damage to one of the arms. The damaged arm I can only presume was bent to the point of creating a "crimp" in the arm and also caused the shell to pop-out and over it's casing guides (I had to use a standard screwdriver to re-open the casing enough for the body to pop over the casing guides and back into place).

One of the motors has been damaged enough to produce a light, barely detectable, noise - when compared to the near silent whistle of finger-spinning the motor, this one has an additional noise.

The wire-mesh of the under-arm (a vent?) was "mushed" inward.

One of the 4 Antenna Connector Covers went MIA and was recovered later - (these things fall off easily BTW).

The system now reports that the Forward Sensors need calibration, and are now non-functional (as they seemingly were before) - I don't know how to re-calibrate them.

After a detailed inspection and feeling confident that the aircraft would still fly, I ran some tests.

First, with the props off, just to make sure the motors weren't going to explode or do something else equally fascinating - they did not show signs of concern, but I'm quite sure the impacted motor should be replaced.

Then some low-altitude backyard control tests. The forward sensors won't work at all, there is a constant warning informing me they need re-calibration. Generally, it seemed to fly okay.

My trust in the product is greatly challenged by the fact that it completely ignored a critical command that would have prevented the incident, and after making contact, the aircraft shot off in a direction at an uncontrollable speed. It should have shut down or at least tried to regain its level.

I would have posted yesterday (the day of), but my computer's OS crashed, then the HDD crashed and is now undergoing a recovery process. I also wanted time to think this over, examine the flight log thoroughly, and "cool-off" before posting (this would have seemed a lot angrier yesterday).

I will post some photos of the aircraft and flight log soon. I will consider posting the video after I investigate and can confirm that the clock is still working and completely undamaged. o_O I would like to post the video of the flight recording that shows the CSCs along with the flight , just as it does in the app; any thoughts on how to do this?

I would like to hear from DJI Support regarding this, and also from anyone else that has has their aircraft ignore a CSC.

Information on how to go about re-calibrating the forward sensors would be swell.

EDIT: I will be testing the clock for any frequency emissions (magnetic emissions would affect its directional awareness, not likely its communication with the controller); Frequency emission is the only possible thing i can think of that would cause the UAV to completely ignore the controller.

Thanks, and Fly-On Banana Spider One Bravo Delta Niner.
 
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Here are some pics of the P4.

1. "Crimped" shell casing.
20160429_104628.jpg


Arm Alignment Shot:
20160429_104643.jpg


Screwdriver marks from having to Re-Fit the shell onto itself.
20160429_104653.jpg
 
It should also be noted that the video recording shows horizontal distorted bands across the entire video (for a short moment) that appear to be what I would call "corrupted JPG information" (from previous observations of corrupted JPG files that show a partial image, with some of the image being horizontally "colorized" in a very distorted way.

Interestingly enough, the video playback of this incident shows the exact distortion happening, well prior to the incident, and therefore not possibly caused by this incident. This is not the first occurrence of this distortion, once again, I wrote it off because it did not manifest again until this flight. I'll try to post one of the clips.

Maybe there is a relation to the CSCs being ignored and this distortion? hmm..

All this aside, how the heck do I get the gimbal to keep level during a YAW maneuver? In a 360 YAW maneuver, the horizon is level until I YAW, as I rotate, the world tilts one way, and as I continue, it re-levels, and as I continue it tilts the other way and so on...
 
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****! I hate to see your beautiful bird all tore up like that! Was there much wind at all when this happened? I have noticed that inside with the sensors on that if its real low and something gets real close in front of it, that it essentially not move with any movement command at times. And if wind was blowing it could have blown you into the clock face maybe. Are you sure that object avoidance was not going to stop it when you first flew up to it? Because if your flying slow it will get within 3ft or so.
 
****! I hate to see your beautiful bird all tore up like that! Was there much wind at all when this happened? I have noticed that inside with the sensors on that if its real low and something gets real close in front of it, that it essentially not move with any movement command at times. And if wind was blowing it could have blown you into the clock face maybe. Are you sure that object avoidance was not going to stop it when you first flew up to it? Because if your flying slow it will get within 3ft or so.

Hardly any wind all day - was a beautiful day to fly ATI, but I was in P mode because I'm still new to drone piloting. I was going slow, very slow - the aircraft didnt respond to my pull-back command, s it slowly drifted into the clock face.. perhaps it was mesmerized.. like "wow.. i've never seen anything sooooo beautifulll......" much like mosquitoes with UV light.. Object avoidance kept the UAV from other objects, just not this time.
 
You can see if DJI will repair the quad if you send them the Flight Logs.
 
You can see if DJI will repair the quad if you send them the Flight Logs.

I'm thinking that would be in their best interest. I don't know how to upload the flight logs yet. I need some guidance in that department.
 
Always remember this: switch to ATTI mode immediately when having trouble with automatic flight system. You will gain full control and manually land it as soon as you can.
 
You are aware that the csc commands were changed after the last firmware update. Also I'm not sure how a csc would've helped you in this case . Unless I missed something but killing the motors midair would've only sent your phantom falling to the ground. Also obstacle avoidance is disabled in atti mode. Your phantom did exactly what it was suppose to do. Pilot error kills another innocent phantom .
 
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Always remember this: switch to ATTI mode immediately when having trouble with automatic flight system. You will gain full control and manually land it as soon as you can.

A good idea, however, I don't think there would have been enough time to pull off a mode switch and re-issue a pull-back. It was managing to keep good GPS position control, so I had control up to the point where the UAV was about 2' from the structure when i felt that it was drifting more than it should have been. When I pulled back, the UAV was inches from the structure - if the UAV would have responded to the controller commands, it would have had just enough time to avert contact. Another consideration would be, the UAV ignored a controller command, would it have ignored the command in another mode? I'm not volunteering to test that hypothesis.

When I say inches, it had at least 10" of time to respond. as it was moving slowly to begin with, the pull-back would have all that was needed.

I still have to go to the location to test for frequency emissions at the structures location.
 
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A good idea, however, I don't think there would have been enough time to pull off a mode switch and re-issue a pull-back. It was managing to keep good GPS position control, so I had control up to the point where the UAV was about 2' from the structure when i felt that it was drifting more than it should have been. When I pulled back, the UAV was inches from the structure - if the UAV would have responded to the controller commands, it would have had just enough time to avert contact. Another consideration would be, the UAV ignored a controller command, would it have ignored the command in another mode? I'm not volunteering to test that hypothesis.

I still have to go to the location to test for frequency emissions at the structures location.
Pilot error
 
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You are aware that the csc commands were changed after the last firmware update. Also I'm not sure how a csc would've helped you in this case . Unless I missed something but killing the motors midair would've only sent your phantom falling to the ground. Also obstacle avoidance is disabled in atti mode. Your phantom did exactly what it was suppose to do. Pilot error kills another innocent phantom .

I think you're misreading here. "A CSC" in this context is meant to say "a Control Stick Command" and not necessarily a "Motor Shutdown Command" - which would have helped as the incident happened at less than 8' AGL, as the UAV would have only fallen about 7' instead of shooting off 35' at full speed into a brick wall. I'm saying that I issued a Control Stick Command to Pull-Back, and that command was not responded to.
 
I think you're misreading here. "A CSC" in this context is meant to say "a Control Stick Command" and not necessarily a "Motor Shutdown Command" - which would have helped as the incident happened at less than 8' AGL, as the UAV would have only fallen about 7' instead of shooting off 35' at full speed into a brick wall. I'm saying that I issued a Control Stick Command to Pull-Back, and that command was not responded to.
The last firmware update changed the control stick command to right stick down and in while pressing the RTH button.
 
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I think you're misreading here. "A CSC" in this context is meant to say "a Control Stick Command" and not necessarily a "Motor Shutdown Command" - which would have helped as the incident happened at less than 8' AGL, as the UAV would have only fallen about 7' instead of shooting off 35' at full speed into a brick wall. I'm saying that I issued a Control Stick Command to Pull-Back, and that command was not responded to.
Also atti mode disables obstacle avoidance . It will also drift because of forward momentum. Just because there was no wind does not mean it was OK to use this mode while flying around obstacles. Atti mode is for experienced pilots.
 
I think you're misreading here. "A CSC" in this context is meant to say "a Control Stick Command" and not necessarily a "Motor Shutdown Command" - which would have helped as the incident happened at less than 8' AGL, as the UAV would have only fallen about 7' instead of shooting off 35' at full speed into a brick wall. I'm saying that I issued a Control Stick Command to Pull-Back, and that command was not responded to.
I'm sorry you crashed but your phantom operated just like to should have.
 
The last firmware update changed the control stick command to right stick down and in while pressing the RTH button.
Flyer, your not understanding what he is saying, I see exactly what your saying because I thought the same thing at first. He's not using the abbreviation in the classic sense we would, he's saying it as his way of saying he put the Input of the backup command, not trying to shut down the aircraft. Now I have a question or two tho
 
Did you, ok, when did you notice then that the CA, or OA wasn't working? Everything was OK, but weren't you like "wait a sec, what's going on, why no beeps and CA bars across the screen?"
Because the other day I was bring my bird down because it was already windy but it picked up hard, I have the "thread the needle" when coming thru the backyard like that, and the trees are high, like 85' -100' tall suckers. As I entered the canopy the OA went beserk on me (oh yeah and had been giving me false positive readings when nothing present the whole flight, which was only maybe 6-7 minutes) anyway the OA is beeping and throwing crap out, and the bird froze, I mean it wouldn't pull back like I needed it to, I couldn't go forward either obviously, and either way would have been fine, it's the way the branches are in relation to the bird, so I couldn't even test side to side, too close. It's wouldn't yaw, it would however go up, but with it acting like it was I didn't want a bird that wasn't listening to commands even higher! Finally that's what I did tho to shut up the OA and regain control.
I found a large bug that I meticulously cleaned out the other day, had left a large part of himself in the crevice that I so carefully thought I cleaned all the way. Did a recalibrate and it's back working fine.
I find that by using one of the "C" buttons that shoots camera up and down real fast, that seems to really help when the horizon is off, if it's bad, it makes it a lot better, like 80% but doesn't make it perfect.
 
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Flyer, your not understanding what he is saying, I see exactly what your saying because I thought the same thing at first. He's not using the abbreviation in the classic sense we would, he's saying it as his way of saying he put the Input of the backup command, not trying to shut down the aircraft. Now I have a question or two tho
Ok I get what he's saying now. Sorry about the misunderstanding


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Did you, ok, when did you notice then that the CA, or OA wasn't working? Everything was OK, but weren't you like "wait a sec, what's going on, why no beeps and CA bars across the screen?"
Because the other day I was bring my bird down because it was already windy but it picked up hard, I have the "thread the needle" when coming thru the backyard like that, and the trees are high, like 85' -100' tall suckers. As I entered the canopy the OA went beserk on me (oh yeah and had been giving me false positive readings when nothing present the whole flight, which was only maybe 6-7 minutes) anyway the OA is beeping and throwing crap out, and the bird froze, I mean it wouldn't pull back like I needed it to, I couldn't go forward either obviously, and either way would have been fine, it's the way the branches are in relation to the bird, so I couldn't even test side to side, too close. It's wouldn't yaw, it would however go up, but with it acting like it was I didn't want a bird that wasn't listening to commands even higher! Finally that's what I did tho to shut up the OA and regain control.
I found a large bug that I meticulously cleaned out the other day, had left a large part of himself in the crevice that I so carefully thought I cleaned all the way. Did a recalibrate and it's back working fine.
I find that by using one of the "C" buttons that shoots camera up and down real fast, that seems to really help when the horizon is off, if it's bad, it makes it a lot better, like 80% but doesn't make it perfect.
You make a good point. I never thought about checking the OA camera before flight. I'll be adding that to my preflight check list.


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