DJI Spark Fell From The Sky From 400'

[jbhamel]

Hello All,

Yesterday my spark fell from the sky from 400' after the battery died. The problem I was having before I took off was that it was not showing the correct altitude when above 15' and i was testing it in a open field so as not to damage or hurt someone. When i saw that I was having the same problem I hit RTH only to see it rise to 400' and the only control I had was moving the camera. This is the second time it has happened but I regained control last time and brought it home safely. This time I had to watch as it was not moving at all but just hanging in the sky and only allowing me to pan the camera. As a last ditch effort I disconnected the controller in hopes to force it to land. Then I had to listen to the controller tell me over and over again that it had a critically low battery. This lasted until I could not see the drone crash and only had the video before it fell due to no battery. I did upload the data file to my dropbox account and the video before it fell but I am not sure how to let anyone analyze it. I did find the spark and it landed in a pile of hay with no viable damage and only missing the CPL filter. I did reset the spark back to factory setting and refreshed the firmware and it does fly fine for now but i am curious how it locked up on me. Thanks for any help!

Jim

 

[nilanjan118]

It seems to be a case of the bottom sensors sensing something underneath causing the aircraft to rise in altitude. Sometimes it can happen due to mist, fog, reflection from snow, water. It can also happen if your sensor is not clean. Please locate your flight log from your mobile device and upload it in the site below. You can then share it here for someone to have a look.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

 

[jbhamel]

It seems to be a case of the bottom sensors sensing something underneath causing the aircraft to rise in altitude. Sometimes it can happen due to mist, fog, reflection from snow, water. It can also happen if your sensor is not clean. Please locate your flight log from your mobile device and upload it in the site below. You can then share it here for someone to have a look.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

Than you very much!

 

[jbhamel]

It seems to be a case of the bottom sensors sensing something underneath causing the aircraft to rise in altitude. Sometimes it can happen due to mist, fog, reflection from snow, water. It can also happen if your sensor is not clean. Please locate your flight log from your mobile device and upload it in the site below. You can then share it here for someone to have a look.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

I get secure connection failed when i try it.

 

[nilanjan118]

I get secure connection failed when i try it.

Your browser or firewall must be blocking it. You should be getting an option below to add exception and open it.

 

[jbhamel]

This is the file I can view in the flight log viewer.

 

[nilanjan118]

I uploaded your flight record and here is the link.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

Just as i said, your bottom sensors were sensing some obstacle all the time and so RTH was making the AC go higher and higher. But you switched to P-mode, regained control and was auto landing at 8:38 with 36% battery left. What happened after that? Why did you switch to Sports mode and go 450 ft. away from home?
At 9:25, 31% battery left and the AC goes into RTH again as the remaining battery is only enough to reach home. It does return home but keeps going higher and higher till 11:01, reaching an altitude of 390 ft. Auto landing from 11:07 at 15% battery. Last logged altitude is 31.2ft at 14:23. It probably turned off at that point and fell to the ground.

 

[jbhamel]

Thank you for the help! I put it sport mode because it did not look like it was even
Moving towards me to land. I was desperate at this point because it happened to me before and I almost lost it and did not want to lose it.

 

[nilanjan118]

Thank you for the help! I put it sport mode because it did not look like it was even
Moving towards me to land. I was desperate at this point because it happened to me before and I almost lost it and did not want to lose it.

I don't understand why you would want to put it in Sports mode when it is landing close to home point at 8:38. Anyway, you need to check why the bottom sensors are getting triggered all the time. Do you have anything installed below your AC? If not, please check whether the sensors are clean. As far as I know, the bottom sensors should not be active at more than 20 ft above ground.

 

[jbhamel]

Once again thanks for your help. It may have shown it was returning home but it wasn’t coming down. I put in sport mode to make it come down faster. I know the numbers show is was going home but looking at the camera and altitude readings it wasn’t . The problem I had was no control over it. I could not bring it down. That’s why it stayed in the sky until it crashed.

 

[sgrinavi]

400' drop with zero damage! Tough little bird!

Mine was doing some of that too, I never had it go up to limit altitude and hang there until it ran out of juice, mine actually fell out of the sky while still under power reading zero altitude - it thought it had landed.

Same as you, I re-set the firmware and the problem went away.

 

[twickers14]

Wow. So sorry for the crash that happened. You seem to have got off reasonably lightly. What a fabulous facility it is to have the likes of Nilanjan and many others available to give helpful focused advice and help. Thank you all.

 

[jbhamel]

400' drop with zero damage! Tough little bird!

Mine was doing some of that too, I never had it go up to limit altitude and hang there until it ran out of juice, mine actually fell out of the sky while still under power reading zero altitude - it thought it had landed.

Same as you, I re-set the firmware and the problem went away.

Well after looking at the flight record it looks like it came down behind and to the right of me to 27’ before the battery died. That would explain the lack of damage ?

 

[hiflyer]

Nilanjan seemed to be right on the money with his analysis. I put a skin on my spark and carelessly very slightly covered a bottom sensor. The second time I flew, the Spark shot up like a rocket and for a short time I couldn't control it. I eventually got control but the indicated altitude was way off. I was able to land it. I don't know why it behaved properly during the first flight or why I was able to get control of it. After I somehow figured why it all occured I carefully opened the hole in the skin around the sensor and end of problem.
I don't blame you for flipping switches when your spark took off...At times of stress the vision narrows...

 

[jbhamel]

Nilanjan seemed to be right on the money with his analysis. I put a skin on my spark and carelessly very slightly covered a bottom sensor. The second time I flew, the Spark shot up like a rocket and for a short time I couldn't control it. I eventually got control but the indicated altitude was way off. I was able to land it. I don't know why it behaved properly during the first flight or why I was able to get control of it. After I somehow figured why it all occured I carefully opened the hole in the skin around the sensor and end of problem.
I don't blame you for flipping switches when your spark took off...At times of stress the vision narrows...

The other only problem I have with that idea is that I have cleaned the sensors on the bottom because this has happened once before but I was able to get it down. So I was very aware of the sensors not being covered and clean. Don’t get me wrong, I really appreciate the help he gave me on my problem ?

 

[jbhamel]

The other only problem I have with that idea is that I have cleaned the sensors on the bottom because this has happened once before but I was able to get it down. So I was very aware of the sensors not being covered and clean. Don’t get me wrong, I really appreciate the help he gave me on my problem ?

But I do believe there is something wrong with the bottom sensors?

 

[nilanjan118]

But I do believe there is something wrong with the bottom sensors.

If you are absolutely certain that there is nothing blocking the bottom sensors and they are clean as well, you should contact DJI support immediately. You should not risk flying your drone with a faulty bottom sensor.

 

[jbhamel]

I did reset to factory settings and then reinstalled the firmware so I will go to the field and test the altitude to see if it’s showing the correct height. It only seems to screw up when I hit the RTH.

 

[nilanjan118]

I did reset to factory settings and then reinstalled the firmware so I will go to the field and test the altitude to see if it’s showing the correct height. It only seems to screw up when I hit the RTH.

Make sure you test at an altitude of 30ft+. Keep an eye on the altitude displayed in the app. If the bottom sensors are still getting triggered, the altitude display will flicker and give absurd values occasionally. Do not hit RTH if it happens. Fly manually and within VLOS. Pull the left joystick fully down to make the AC come down.

 

[jbhamel]

Thank you for the advice and I will let you know my results ?