Drone ignored pull-back command = crashed

[ZaqHydN]

It's also worth noting (for our industry) that the Power Companies are starting to contract UAV crews to create video inspections of transformers, RF lines, solar fields and other related industrial or highly dangerous tasks. You'll need your 333 exemption, FAA registered UAV, the right insurance and a sport pilots license (you'll likely need to know the right people).

 

[ZaqHydN]

How do you know? It's the most common form of crash.

Good luck with that. Taking off from ferrous (magnetic) material like metal tables, car roofs, etc. can cause the compass to provide erratic and incorrect readings.

As for interference, RF will not cause anything other than a loss of communication and RTH. It will never cause erratic flight of the drone. However, EMI at strong enough levels WILL cause the compass to provide incorrect results. I've seen when within 100ft of high voltage regional power lines. Local power lines like the ones pictured are not strong enough to be a problem (unless you hit them).

My man, I'm not going to argue with you.

One day you might be the one holding the controller, with good batteries, a healthy aircraft, a strong signal while pulling back at 100% only to watch your UAV ignore your sticks to slowly drift forward into an incident. Argue that all day, it just doesn't work out.

I wanted to share the incident for those that might have a similar occurrences and naturally am hoping to find some logical explanations that could reduce incidents.

You can land on metal surfaces. You can take off from a metal surface too. In A-Mode (sticks-only), the compass doesn't matter. It does take gentle patience and focus, but you can do it. Only in P-Mode is when it gets all weird when I try to land on the table, like it's scared of it. Try it in A-Mode, you'll like it.

 

[Stealthmatt]

My man, I'm not going to argue with you, if you just want to blame me, that's cool - you're not the warranty guy and in the end, it doesn't matter because you weren't the one holding the controller, pulling back at 100% only to watch your UAV slowly drift forward into an incident. Argue that all day, it just doesn't work out.

You can land on metal surfaces. You can take off from a metal surface too. In A-Mode (sticks-only), the compass doesn't matter. Only in P-Mode is when it gets all weird when I try to land on the table, like it's scared of it. Try it in A-Mode, you'll like it.

So is that what you were in? A mode when flying around the clock?

Maybe VPS caused issues as well?

Can you take a video of your overlay of flight controllers for flight replay from your tablet device?

This will show 100% that your P4 drifted while you were trying to press 100% backwards.

 

[ianwood]

One day you might be the one holding the controller, with good batteries, a healthy aircraft, a strong signal while pulling back at 100% only to watch your UAV ignore your sticks to slowly drift forward into an incident.

You're awfully confident of your conclusion. Post the DAT and log files. We can see exactly what control input was applied and how the craft responded. Very easy to determine.

You can land on metal surfaces. You can take off from a metal surface too.

I'll say it again, ferrous material is to be avoided.

 

[Skyeyevideo]

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 , 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.

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. 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.

I'm sorry to hear this, I had the same on my P3P. Was flying slowly down a driveway and as approaching some shrubs, powered off, drone hovered in GPS, then I pulled right stick back to reverse and momentarily it did before lurching forward, clipping a branch and tumbling 10 feet to ground where the camera completely detached itself from the body. I don't know why it ignored my command but it was expensive and doesn't fill you with confidence.

There was a concrete gate post with a light on it nearby, could this have had an effect?

I havent checked the flight log as P3P away being repaired right now,,

 

[ZaqHydN]

Coming very soon to a thread near you:

 

[ZaqHydN]

Expensive and time-consuming loss, sorry to hear you've joined the Propbusters Club.

I don't know why it ignored my command but it was expensive and doesn't fill you with confidence.

The bottom line when it comes to the purpose of this discussion. I bought the P4 with the intention of using it professionally (in due process), and now I'm concerned that it might randomly have an incident like this at someone's wedding or event. Not very assuring to experience this type of equipment failure.

There was a concrete gate post with a light on it nearby, could this have had an effect?

Highly unlikely; The light would have to be emitting a relative signal (near or related harmonic radio frequency) strong enough to pollute your control signal, very much like losing your favorite radio station to some backwoods banjo bangin station while you're driving through west TN.

I'm aware that metallic or energized objects may cause the navigational flight aids or sensors to go wacky; I'm' also aware that the interference potential is based on the triangular relational distance between the controller, the object and the UAV. The triangular relation is ideally 95 degrees, but not always possible to maintain. Basically, I try to be closer to the UAV than the object to maintain dominant signal strength. Naturally, vertically gifted flights won't allow this condition, so I make sure to keep in mind the potential for signal pollution as the UAV gets further from the controller, keeping greater, safer distances from potential sources of interference. Part of my preflight is to do a site survey, including any flight paths I might take.

In the case of this incident, the only threat was invisible and undetectable, which means there was no precaution I could have considered to avoid this from happening other than scrubbing the shot plan. Well, that's fine if all I wanted was a photo of the clock, but this was meant to be a cool scene for a video - again, imaging if it was someone's wedding. ouch. Pulling this type of scene requires practice, especially if you're going to do it cinematically and with actors (or at an event or with a wedding party). If you're a pilot for motion pictures and working with actors, and your DJI Inspire not only ignored a stick command, but also took out a set prop and flew into one of the actors at full-tilt - you'd likely get fired and fried (sued).

As for flying near metal objects...

To anyone who hasn't figured it out yet, A-Mode flight turns off the navigational flight aids and you can do close circles around metal poles if you wanted to, so long as your radio signal is the dominant signal along your flight path. Anyone who disagrees is welcome to join me on the field for some flight exercises and drills instead of telling me it can't be done.

I was in P-Mode - very close proximity to the P4, GPS signal was strong, Batteries good and, well, "Still, the sticks should work."

 

[ZaqHydN]

You're awfully confident of your conclusion. Post the DAT and log files. We can see exactly what control input was applied and how the craft responded. Very easy to determine.

Yep. I'm confident because I'm educated in the related areas, I have examined the playback with stick command overlay many times, and to assure you that I was there when it happened, and watched it happen while performing said stick commands. The log file was posted on the thread, someone even uploaded it to the healthydrones site, only to discover what I discovered - everything looked good up to the point of contact.

If you were standing on a street corner and saw a horse walking backwards through an intersection, you'd be confident that it happened, however unlikely to anyone else, they'd want to see a video of it so you could prove you weren't full of air. I'm more than happy to provide DJI with the data they need; repairing the P4 won't solve the puzzle, it will only make it go away until it happens again, possibly on one of your sets with set props that would have to be repaired and actors that can sue. Just a thought.

I'll say it again, ferrous material is to be avoided.

I agree, they should be avoided - only logical. To tell me that I can't do VTOL's from a metal picnic table or to fly around metal objects is no different than me telling you that horses can't walk backwards.

Not a recommended exercise for people that aren't very familliar with A-Mode flight, but "Still, the sticks should work."

 

[ianwood]

Post the DAT file. Healthydrones won't tell you anything.

 

[Stealthmatt]

Yep. I'm confident because I'm educated in the related areas, I have examined the playback with stick command overlay many times, and to assure you that I was there when it happened, and watched it happen while performing said stick commands. The log file was posted on the thread, someone even uploaded it to the healthydrones site, only to discover what I discovered - everything looked good up to the point of contact.

If you were standing on a street corner and saw a horse walking backwards through an intersection, you'd be confident that it happened, however unlikely to anyone else, they'd want to see a video of it so you could prove you weren't full of air. I'm more than happy to provide DJI with the data they need; repairing the P4 won't solve the puzzle, it will only make it go away until it happens again, possibly on one of your sets with set props that would have to be repaired and actors that can sue. Just a thought.



I agree, they should be avoided - only logical. To tell me that I can't do VTOL's from a metal picnic table or to fly around metal objects is no different than me telling you that horses can't walk backwards.

Not a recommended exercise for people that aren't very familliar with A-Mode flight, but "Still, the sticks should work."

and post a video of your flight stick moments from your device that you used. (go into previous flights and you can overlay on the map your stick movements. Upload a video of this to YouTube)

 

[ZaqHydN]

Post the DAT file. Healthydrones won't tell you anything.

Is the DAT file the same as the flight log? If so, I've posted the link to the upload.

If not, what's the DAT file, where can I find it?

Online with support at the moment.. Still, the sticks should work..

 

[ZaqHydN]

Flight log link: Phantom Log Viewer - PhantomHelp.com

 

[lawman0210]

I don't mean to insult you but you did pull back on the right stick?

 

[ZaqHydN]

I don't mean to insult you but you did pull back on the right stick?

That's been brought up. I ignored it because it was almost silly to me.. But you're right to ask I guess..

For the public, yes, it was the Right stick, not the Left stick. Still, the sticks should work..

 

[ZaqHydN]

... video of your flight stick moments from your device that you used. (go into previous flights and you can overlay on the map your stick movements. Upload a video of this to YouTube)

Is there a way to export the playback with the overlay?

 

[Stealthmatt]

Is there a way to export the playback with the overlay?

Just take a quick video with your phone, only needs to be like 20 seconds and upload to youtube. There is no way I know of how to export the playback with overlay.

I think the DAT files will show the stick commands as well (this is different to the logs you got off your portable device)

The P4 DAT files are stored on the flight data recorder in the aircraft (same as P3,Inspire)
With the P4, they are accessible from the Assistant2 software. (which means you have to use the provided USB cable plugged into your Phantom 4)

 

[ZaqHydN]

Just take a quick video with your phone, only needs to be like 20 seconds and upload to youtube. There is no way I know of how to export the playback with overlay.

I think the DAT files will show the stick commands as well (this is different to the logs you got off your portable device)

The P4 DAT files are stored on the flight data recorder in the aircraft (same as P3,Inspire)
With the P4, they are accessible from the Assistant2 software. (which means you have to use the provided USB cable plugged into your Phantom 4)

Thanks. I'll have to look into the Assistant2 SW.

 

[arcaine25]

Thanks. I'll have to look into the Assistant2 SW.

I have to say something as a relatively new "participant" to the forums (i've read the forums for some time before trying to contribute and ask real actual questions). Any new user that happens to see how this thread was handled from the get go would turn them away. NONE of us were there with the OP, PERIOD. The logs show no signal interference, and he clearly knows what he is doing for what he wants to do. Second, while ferrous metal object might affect most of us, including myself (I can't launch from metal objects without serious compass calibration issues, ATTI or GPS mode), it doesn't mean that he does as well. Different birds / areas / conditions will behave differently than any others experiences. no 2 experiences will be 100% IDENTICAL EVERY TiME from user to user.

Quite frankly I am appalled at the immediate speculation that he doesn't know what he's doing. He says he pulled back on the right control stick, and it didn't respond. CLEARLY there is an issue, and not one person can say they haven't seen a phantom do something strange, maybe not that in particular, but definitely something "abnormal". Hell, just the other day I was demonstrating OAS to some neighbors like I have tested probably 15 times since purchasing my P4, and for whatever reason it just decided to initiate and work AFTER it almost took me out. (yes, like an idiot I fly it TOWARDS me, in perfect alignment, watching in the APP to make sure it detects the "object" which is me, and it sees it, shows where, etc etc, but didn't try to stop until I had to duck, it passed over he, then the beeps started BEHIND me, and it applied the brakes).

This whole thing feels like dealing with DJI directly, who will try everything in their power to not have to admit a problem with the product, and prove it was the pilots error, or he was in an area he wasn't flying in. I can tell you, that while transformers and power lines are bad, and you shouldn't fly close to them, those are not the SUPER HIGH powered versions you see wreaking havoc on FC's and compasses that cause crashes, these are every day transformers that we ALL have nearby in town. The only reason you wouldn't see these in regular patterns is if you lived in the sticks., and even then they are every so often, because a home needs power!

Again, I get that a lot of fly away and other issues ARE user related, but what ever happened to benefit of the doubt? Would everybody like for someone to assume they are a ******* until you were able to 100% exonerate yourself? What happened to community, to help try and solve an issue instead of immediately looking for every possibly reason to blame someone who shares in the same hobby? I'd rather help him to no end find the issue / answer, so it doesn't get repeated than to try and beat him down and say "you just suck as a pilot, and you shouldn't own a phantom if you can't fly it", that is just BS and arrogant.

/rant

 

[ianwood]

Welcome to the forum. Over time you'll find that there are numerous claims of "it didn't do what I told it to" which in a reasonable percentage of events turns out to be operator error. Some are indeed equipment failures e.g. battery shut downs, ESC failures, props flying off and other defects that are not user error.

In the absence of evidence, I will always preface my assumptions as such. Sometimes, it's more obvious than others. This is no different. Is it operator error? Probably. Is that confirmed? No. We need data to confirm or refute the most likely cause.

As for the influence of ferrous objects, that's just basic knowledge. The compass is a magnetometer. It's in the landing gear. It is influenced by all ferrous materials at close range. To say taking off from a metal table is OK is wrong and misleading. Just because someone has done it without incident doesn't make it safe especially when there is overwhelming evidence to the contrary.

 

[arcaine25]

Welcome to the forum. Over time you'll find that there are numerous claims of "it didn't do what I told it to" which in a reasonable percentage of events turns out to be operator error. Some are indeed equipment failures e.g. battery shut downs, ESC failures, props flying off and other defects that are not user error.

In the absence of evidence, I will always preface my assumptions as such. Sometimes, it's more obvious than others. This is no different. Is it operator error? Probably. Is that confirmed? No. We need data to confirm or refute the most likely cause.

As for the influence of ferrous objects, that's just basic knowledge. The compass is a magnetometer. It's in the landing gear. It is influenced by all ferrous materials at close range. To say taking off from a metal table is OK is wrong and misleading. Just because someone has done it without incident doesn't make it safe especially when there is overwhelming evidence to the contrary.

In RE: to the ferrous object comment, I have always had issues with it, and know that it interferes with proper function, I was just stating that his experiences were obviously different than any of ours. Why? I am not sure, but his was no problems.
I also get the whole mostly user error argument, as a lot of times there is definitely some form of error, but in this case the logs he uploaded seemed to say otherwise, yet people are still saying it's his fault. I know that after the log files he was asked to upload proved that there was no signal issues that now a DAT file is wanted, but at what point do any of us just say "hmmm, well the logs seem to show no error in this or that" and admit that it might possibly NOT be user error?
I just personally like to give people somewhat the benefit of the doubt, and we can assume to ourselves that it's pilot error, but no need to flat out call the guy who is asking for help a liar or an idiot (whether literally or implied) until ALL the facts are on the table. Surely there has to be a more "human" element and respect level to our replies in trying to help someone asking for it. All of us started out knowing nothing and making mistakes at one point or another, and even after several years of flying and building, I still make occasional mistakes or assumptions that I should have otherwise followed my own rules of, but we're human, and mistakes happen.. It was merely my observation though that maybe people need to "go a little easier" on other fellow human beings who may or may not have your (the person making assumptions) level of expertise.

Thanks for the welcome, and I look forward to more involvement here.