fansc99f2447 Posted at 2017-12-30 15:20
Looked like it was pretty cold. What happens if the downward sensor gets condensation?  Does it get a false ground level reading and try to fly upward away from the "phantom" ground?

I shouldn't imagine so?
I've seen people fly the spark in snow and light rain, and even land on water without any issues. No that I would.

_zine Posted at 2017-12-30 15:42
I would also be keen to see the log.

The fail-safe should be to descend immediately, to ascend to ridiculous altitudes. ... Though slightly impressed to see the Spark could fly so high.

I think you missed the part where I gave a theory on why it went higher.  My theory is that it was trusting the VPS sensors for height over the IMU/barometer.  Because of this, it thought it was only a few feet off the ground, not 1500 feet in the air.  So it was trying to rise to the 20 m RTH height.  

I don’t suppose you have a video from the video cache on your phone of the flight?  Could you do a screen record of the Flight Record playback from DJI Go 4?   I’m curious to see which altitude it shows during the flight.  

Also, you mention the UK law for height.  I believe you willingly chose to exceed that yourself.   The malfunction with the RTH occurred after you were already at an illegal height.

Kloo Gee Posted at 2017-12-30 14:37
Having looked at the logs in detail, I believe the fateful event occurred at 222.8 seconds (3m 42.8s).  
I am definitely not an expert at interpreting the logs, so I will happily take corrections if I've misinterpeted anything.

Sorry I didn't answer your questions. Please see response below in red:

Questions I don't have answers for:- Did you manually put it in RTH mode at this point or was it automatically triggered by the Spark?
     * Based on what I see, I assume you manually put it in RTH.
- It automatically set the RTH point, but I Always manually set the RTH point just to be safe.

- Why is both IMU Altitude and VPS Altitude showing values?  I would expect VPS Altitude to show 0 once it gets above a certain height.
- Why was there a forced landing at 185.8 through 206.3 seconds into the flight?
     * Is it possible there was at least a small cloud or some water vapor got on the downward sensors?
- Please see my recent uploaded images. It was dry and clear.

     * Did you manually switch it back to Sport mode to get it out of this mode?  I know some that have got stuck in fog have used Sport mode to get out of it.
- I didn't change the 'sport mode' setting. It was in 'sports mode'  as I was up above trees and wasn't worried about hitting anything .. wanted to have some fun zipping around the park before heading home!


- Why does the altitude rise rapidly while in GO HOME mode?  There are not RC inputs that could have caused this.
     * Is it possible that RTH was reading the VPS altitude as its actual altitude instead of the IMU/barometer height and because of this it kept trying to raise up to the RTH Altitude setting of 20m?
- No idea. but it could have something to do with the warning message received at 4:13min?

_zine Posted at 2017-12-30 15:36
Hi Kloo

Thank you for the detailed response.

I’m not looking at the logs right this moment as I type this, but I think at 4:13 when you had the command timeout, it was already out of control starting at the point RTH was initiated.  This happened at 222.8 seconds (3m 42.8s).

I completely understand wanting your Spark back.  When I had a situation where I lost control of my Spark and had a crash several months ago, it was a helpless feeling.  In my opinion, I think DJI should cover your warranty replacement.  When the RTH was initiated, it should NOT have kept elevating.  That is an extremely critical bug if it did what I think it did.

_zine Posted at 2017-12-30 15:53
Hi hallmark007

I am very familiar with the controls, as I've done many flights over the past few months, and always fly using the map and waypoint on my iPhone 7 plus.

There is still a full two minutes missing from your log , it’s really impossible to 1 think that no stick movements occurred in those two minutes, 2/ why the aircraft would be so far away from home and at such high altitude.

I would say though if this works out for you that flying without VLOS in manned airspace is to say the least a bit reckless, and doesn’t help the cause of others continually fighting against further restrictions.

Kloo Gee Posted at 2017-12-30 16:09
I’m not looking at the logs right this moment as I type this, but I think at 4:13 when you had the command timeout, it was already out of control starting at the point RTH was initiated.  This happened at 222.8 seconds (3m 42.8s).

I completely understand wanting your Spark back.  When I had a situation where I lost control of my Spark and had a crash several months ago, it was a helpless feeling.  In my opinion, I think DJI should cover your warranty replacement.  When the RTH was initiated, it should NOT have kept elevating.  That is an extremely critical bug if it did what I think it did.

Hopefully, DJI will get back to me with an answer. I'm not going to speculate on the cause of the incident.

if it is firmware bug, then DJI best resolve it asap

hallmark007 Posted at 2017-12-30 16:35
There is still a full two minutes missing from your log , it’s really impossible to 1 think that no stick movements occurred in those two minutes, 2/ why the aircraft would be so far away from home and at such high altitude.

I would say though if this works out for you that flying without VLOS in manned airspace is to say the least a bit reckless, and doesn’t help the cause of others continually fighting against further restrictions.

Let me clarify ... When I am above the tree line and in an open field with nothing around, including birds and the likes, I find it much easier to fly using the map and the onboard camera.

If I am in a build up are, or have obstacles around, including birds, then obviously I will keep an eye on the spark at all time.

Needless to say, it not up to me or you to dictate how others should fly their drone.

_zine Posted at 2017-12-30 17:03
Let me clarify ... When I am above the tree line and in an open field with nothing around, including birds and the likes, I find it much easier to fly using the map and the onboard camera.

If I am in a build up are, or have obstacles around, including birds, then obviously I will keep an eye on the spark at all time.

I’m not trying to dictate how you fly your drone, but just pointing out that flying the way you are flying is both a risk to manned aircraft and if you lose downlink as you did you have no way of knowing which way your drone is heading or how it is responding to your controls .

I’m not to sure reading your posts if you are aware of regulations regarding flying SUA or whether your bothered , but most of what you have said is breaking the rules for the country your flying in, but hey it’s your drone I’m not telling you how or where you should fly it.

_zine Posted at 2017-12-30 16:05
Sorry I didn't answer your questions. Please see response below in red:

Questions I don't have answers for:- Did you manually put it in RTH mode at this point or was it automatically triggered by the Spark?

* Based on what I see, I assume you manually put it in RTH.
- It automatically set the RTH point, but I Always manually set the RTH point just to be safe.
I think we have a miscommunication on language.  I can see from the logs that it automatically set the Home Point location.  I was specifically asking about at the 3:42.8 point in the logs it switches from SPORT mode to GO HOME mode.  Did you hit the Return To Home button to initiate the return to home procedures?

* Did you manually switch it back to Sport mode to get it out of this mode?  I know some that have got stuck in fog have used Sport mode to get out of it.
- I didn't change the 'sport mode' setting. It was in 'sports mode'  as I was up above trees and wasn't worried about hitting anything .. wanted to have some fun zipping around the park before heading home!
So when it had switched to the FORCED LANDING mode at the 3:05.8 point in the logs, you didn't flip the SPORTS mode switch on the RC at the 3:26.4 point?  It just automatically came out of the FORCED LANDING mode and switched back to SPORT mode?

I have a question perhaps.I believe  that in sports mode vps is inactive. When RTH is invoked, I imagine vps is reactivated. Therfore any fog or issues might result in a rth climb?
Ive found from my  experiments that putting your hand under  it at 3 ft alt or so results in a climb. And the altitude reading is all over the place. Just a thought, but coming out of sport mode, esp by invoking RTH might need caution.

Bright Spark Posted at 2017-12-31 01:29
I have a question perhaps.I believe  that in sports mode vps is inactive. When RTH is invoked, I imagine vps is reactivated. Therfore any fog or issues might result in a rth climb?
Ive found from my  experiments that putting your hand under  it at 3 ft alt or so results in a climb. And the altitude reading is all over the place. Just a thought, but coming out of sport mode, esp by invoking RTH might need caution.

You make a very good point.

Bright Spark Posted at 2017-12-31 01:29
I have a question perhaps.I believe  that in sports mode vps is inactive. When RTH is invoked, I imagine vps is reactivated. Therfore any fog or issues might result in a rth climb?
Ive found from my  experiments that putting your hand under  it at 3 ft alt or so results in a climb. And the altitude reading is all over the place. Just a thought, but coming out of sport mode, esp by invoking RTH might need caution.

you are correct , recently i flew my spark in the usual uk cloudy December conditions   , i noticed the vps error when I was 100M up and about 200M out to the west of my location , the spark was trying to land , I was in p mode so pressed RTH , the spark immediately climbed quickly so i cancelled by going into s mode to fly the drone back to me.

Later when I viewed the onboard video back I could clearly see I flew through a mist cloud.

m1n1s Posted at 2017-12-31 02:08
you are correct , recently i flew my spark in the usual uk cloudy December conditions   , i noticed the vps error when I was 100M up and about 200M out to the west of my location , the spark was trying to land , I was in p mode so pressed RTH , the spark immediately climbed quickly so i cancelled by going into s mode to fly the drone back to me.

Later when I viewed the onboard video back I could clearly see I flew through a mist cloud.

Just a thought for future accident prevention- would switching to gesture mode prevent the aircraft flying up in the case of a VPS fault? Since it would then think there was a surface to land on right beneath it and come down instead of going up?

Admittedly, it'd be one heck of a slow descent, but it might be worth considering as an emergency procedure.

Spark still revealing plenty of secrets to me.
I think deactivating vps in sport mode could be abig plus.
Needs testing, but if vps struggles, gets confused etc, sport mode might be the way over water or grass,under bridges (and light  mist dare I say?)
It's no harder to fly slowly.
I had a lucky forced landing -wish I 'd known sport mode would have cancelled it.

_zine Posted at 2017-12-29 13:58
Thank you for your response.

I have uploaded the flight log, enabling you to analyse the flight.

Zine, we do not support to analysis the flight logs with the third party software. Please refer my suggestion in 3# and export the data manually and upload to Dropbox or Google Drive, we'll double check, thanks so much!

DJI Susan Posted at 2018-1-1 01:39
Zine, we do not support to analysis the flight logs with the third party software. Please refer my suggestion in 3# and export the data manually and upload to Dropbox or Google Drive, we'll double check, thanks so much!

Thank you, Susan, this has been done and the technicians are reviewing the data.

_zine Posted at 2018-1-4 01:01
Thank you, Susan, this has been done and the technicians are reviewing the data.

Zine, I just got the latest news that the data analysis has been finished and our support has informed you the result, and please find it as below:

1. The aircraft was working in GPS mode after taking off, the aircraft was affected by the wind from northwest during the flight;
2. At t=03:43, h=167m, d=54.9m, the pilot triggered RTH in the App, but the aircraft didn't go home normally due to the factor of the wind from northwest;
3. At t=06:17, h=485m, d=679.3m, the aircraft was triggered landing by Critically low power;
4. At t=06:24, h=486m, d=716.7m, the flight record disconnected during landing;
5. According to the video you offered, the pilot attached something on the aircraft which directly caused VPS abnormal and the aircraft lost control of height;

Conclusion: Pilot error, no warranty. According to the data analysis, the incident was caused by improper flight environment and misoperation, we are sorry that it is not a warranty case, please kindly understand. I'll attach the screenshots for your reference.

It's easy to blame to 'pilot' to get out of a claim,  when you are well aware that your firmware caused the issue!I had the propeller guards and a gimbal protector, that are always on the drone, and never had any issues .. Until the new firmware!

Why does the drone still climb in altitude, even though it stated it is Landing??? ... Clearly not PILOT ERROR!

And again. You state that the Pilot pressed the RTH, yet the drone flew away!  ... Clearly not PILOT ERROR!

You also noted that the joystick was in the neutral position, yet the drone gained altitude?  ... Clearly not PILOT ERROR!

Please explain these?

DJI Susan Posted at 2018-1-1 01:39
Zine, we do not support to analysis the flight logs with the third party software. Please refer my suggestion in 3# and export the data manually and upload to Dropbox or Google Drive, we'll double check, thanks so much!

It's easy to blame to 'pilot' to get out of a claim,  when you are well aware that your firmware caused the issue!I had the propeller guards and a gimbal protector, that were always on the drone, and never had any issues .. Until the new firmware!

Why does the drone still climb in altitude, even though it stated it is Landing??? ... Clearly not PILOT ERROR!

And again. You state that the Pilot pressed the RTH, yet the drone flew away!  ... Clearly not PILOT ERROR!

You also noted that the joystick was in the neutral position, yet the drone gained altitude?  ... Clearly not PILOT ERROR!

Please explain these?

_zine Posted at 2018-1-5 03:50
It's easy to blame to 'pilot' to get out of a claim,  when you are well aware that your firmware caused the issue!I had the propeller guards and a gimbal protector, that were always on the drone, and never had any issues .. Until the new firmware!

Why does the drone still climb in altitude, even though it stated it is Landing??? ... Clearly not PILOT ERROR!

DJI states that you attached something to the aircraft...just out of curiosity what did you attach?

Tviscomi Posted at 2018-1-5 03:56
DJI states that you attached something to the aircraft...just out of curiosity what did you attach?

propeller guards and a gimbal protector,

_zine Posted at 2018-1-5 04:13
propeller guards and a gimbal protector,
[view_image]

Thanks for the info!

From what I understood, they want to blame the front sensor that somehow detected the hood and made the drone rise up to try to avoid the invisible obstacle.

Dji needs to urgently fix firmware and software issues, otherwise we will soon have banishment of consumer drones around the world, as this lack of quality control is becoming dangerous.

LeOnBR Posted at 2018-1-5 05:20
From what I understood, they want to blame the front sensor that somehow detected the hood and made the drone rise up to try to avoid the invisible obstacle.

Dji needs to urgently fix firmware and software issues, otherwise we will soon have banishment of consumer drones around the world, as this lack of quality control is becoming dangerous.

That can't be correct then, as the drone was in 'sports' mode, and crash detection would have been disabled. ... obviously, DJI is at fault, well the crappy firmware is!

LeOnBR Posted at 2018-1-5 05:20
From what I understood, they want to blame the front sensor that somehow detected the hood and made the drone rise up to try to avoid the invisible obstacle.

Dji needs to urgently fix firmware and software issues, otherwise we will soon have banishment of consumer drones around the world, as this lack of quality control is becoming dangerous.

No, they're (DJI) are saying it interfered with the VPS

What i don't understand totally from the above pictures is that the battery status is the same at both times 3:43 and 6:17 And is the same critical with battery temp -273.1C!!!
How one can believe to other instrument readings if the battery shows all the time, for about 3 minutes, 0mv and cosmos temperature!! In such situations any conclusions can be made by DJI.

Kloo Gee Posted at 2017-12-30 15:59
I think you missed the part where I gave a theory on why it went higher.  My theory is that it was trusting the VPS sensors for height over the IMU/barometer.  Because of this, it thought it was only a few feet off the ground, not 1500 feet in the air.  So it was trying to rise to the 20 m RTH height.  

I don’t suppose you have a video from the video cache on your phone of the flight?  Could you do a screen record of the Flight Record playback from DJI Go 4?   I’m curious to see which altitude it shows during the flight.  

this is a really good theory and I would be hard pressed to try and argue differently... makes you wonder if you set return to home at current alt. would it potentially avoid this issue (if in fact this was the case).  May be something worth looking into for those of us who really want to fly regardless of the temperature being close to the recommended levels

nixuspix Posted at 2018-1-5 06:19
What i don't understand totally from the above pictures is that the battery status is the same at both times 3:43 and 6:17 And is the same critical with battery temp -273.1C!!!
How one can believe to other instrument readings if the battery shows all the time, for about 3 minutes, 0mv and cosmos temperature!! In such situations any conclusions can be made by DJI.

Well spotted. Excellent point.

I have sent this response to DJI support. Let's see how they respond?

_zine Posted at 2018-1-5 04:13
propeller guards and a gimbal protector,
[view_image]

Also out of curiosity, which propeller guards were installed?

Would you mind sharing the video that you shared with the DJI folks?

It was the supplied guards that came with the flymore combo kit
Link to videos:
https://drive.google.com/drive/folders/1eQuGPxOGGPNjJoeZx2PcdsMGgGA5DQTO?usp=sharing

nixuspix Posted at 2018-1-5 06:19
What i don't understand totally from the above pictures is that the battery status is the same at both times 3:43 and 6:17 And is the same critical with battery temp -273.1C!!!
How one can believe to other instrument readings if the battery shows all the time, for about 3 minutes, 0mv and cosmos temperature!! In such situations any conclusions can be made by DJI.

I don't know for sure how their analysis tools work, but I would assume the technician just chose not to be monitoring those particular inputs from the log as they were taking those screenshots.  I wouldn't get too hung up on it because you can quite easily check for yourself information from the logs using publicly available tools.  

LeOnBR Posted at 2018-1-5 05:20
From what I understood, they want to blame the front sensor that somehow detected the hood and made the drone rise up to try to avoid the invisible obstacle.

Dji needs to urgently fix firmware and software issues, otherwise we will soon have banishment of consumer drones around the world, as this lack of quality control is becoming dangerous.

this definitely makes my not want to fly with a hood! But honestly I could see this as a possibility.

_zine Posted at 2018-1-5 03:50
It's easy to blame to 'pilot' to get out of a claim,  when you are well aware that your firmware caused the issue!I had the propeller guards and a gimbal protector, that were always on the drone, and never had any issues .. Until the new firmware!

Why does the drone still climb in altitude, even though it stated it is Landing??? ... Clearly not PILOT ERROR!

The data analysis team has replied your email: the extra attachment on the aircraft affected the vision system of the aircraft, so the aircraft would ascend and that did not mean there is anything wrong of aircraft itself. We can not ensure the performance with the third party accessories, please kindly note and understand. Lydia will keep follow up and update the status for you soon.

DJI Susan Posted at 2018-1-8 03:22
The data analysis team has replied your email: the extra attachment on the aircraft affected the vision system of the aircraft, so the aircraft would ascend and that did not mean there is anything wrong of aircraft itself. We can not ensure the performance with the third party accessories, please kindly note and understand. Lydia will keep follow up and update the status for you soon.

Given the Drone was in 'Sports Mode', then the crash detection sensors were disabled, and any attachment would not have affected the Drone as it was relying on GPS guidance.

Also ... why would it then fly up and away???

If it was 'affected' by the vision, then it should have remained stationary, not fly up &/or away?

Well, the sunhood part only came to surface when DJI uncovered it. Even in this age of flyway and crash and OTG stories all over, I see most of these episodes still pilot-caused - if only because something has changed in the operation of the FW/app that causes us pilot to make more mistakes. Either way it's nothing new, as it's been like that since the P2, and the more popular these DJI quads become, the more cases can be expected.

Not saying this was the case, but, I can confirm that attaching things to these drones can be a bad idea, and definitively so at times. Long before the pano/360 capabilities of GO4 I used to attach my 360 camera to my Mavic Pro. Every time it went fine until one day I was taking pics at sunset some 130m above an avenue here, and it just wouldn't land. This specific time the VPS went crazy with the camera bellow. No matter what I did it just stood there beeping "landing initiated" but wouldn't come down a single feet. Long story short, I positioned it right above me while the battery was draining empty, but thankfully I was able to land it safely with almost 30% power using RTH with some other desperate maneuver I can't honestly even remember!!!

So no more nothing attached to no DJI drone for me. I get the occasional odd behavior, these are high-end, new tech and advanced aircrafts thus prone to issues. That characteristic won't ever change, but in my experience it's still a huge improvement over the old helis and planes we used to fly back in the (not so long ago) days. And those would crash and go crazy also, but we were used to it and could only count on our abilities instead of super fancy GPS, VPS and RT image systems. Now the high degree of automation also means if something goes wrong and system takes over, it can be harder to recover.

It happened to me too. Here is my footage.

I had one one if those sun shades....until one day it cased a gimbal overload and the Spark flew in a deranged manner...never used it again after that and never had the problem.

Sorry for the loss.

Cheers...

Todd in Chicago

P.S.  I can't see how that sunshade would be interfering with the sensors underneath.

_zine Posted at 2018-1-8 04:21
Given the Drone was in 'Sports Mode', then the crash detection sensors were disabled, and any attachment would not have affected the Drone as it was relying on GPS guidance.

Also ... why would it then fly up and away???

In Sport Mode, the 3D sensor will not work, which located in the front of the drone, so that it can not avoid the obstacle, please kindly note. The downward sensor will not be disabled. As for the flyaway, please check my reply in 57#, the environment was not proper for flying.

DJI Susan Posted at 2018-1-8 23:05
In Sport Mode, the 3D sensor will not work, which located in the front of the drone, so that it can not avoid the obstacle, please kindly note. The downward sensor will not be disabled. As for the flyaway, please check my reply in 57#, the environment was not proper for flying.

Thank you for your response ... but nothing was interfering or blocking the downward sensors!
The sunshade doesn't go anywhere near the base.

And whether the condition was good or bad, I still not heard an adequate response as to why the drone gained height altitude, when I pressed the RTH? Also, why did it fly in the opposite direction to the home point after I lost contact with the drone???

I appreciate that I won't get an adequate answer, as DJI is aware it was a fault with the Firmware and would have to accept liability!

As such, you'll just blame the operator so you don't have to compensate.

You are more interested in profits than customer satisfaction.

Had I crashed or lost the drone due to my own negligent, I would fully accept this. But the fact that I lost communication with the Drone, then it gained altitude flew away without any input from me, leads me to believe it's an issue with the Drone Hardware or Firmware!

This is why I am still debating my point.

Again I politely ask:
- Why did the DJI Spark go from 157m to 450m, after I pressed the RTH button?
- Why did the DJI Spark fly in the opposite direction, after I pressed the RTH button?
- Why are the battery reading inaccurately, ie -157? And how can the other reading be trusted if this is false?

I wait for your response to the above.

Thank you

"Thank you for your response ... but nothing was interfering or blocking the downward sensors!
The sunshade doesn't go anywhere near the base."

I am no expert but I can imagine a scenario where a piece of debris catches in the attachment and eventuall shifts position in the strong wind to interfere with the VPS. Just an idea!