DJI Spark Fell From The Sky From 400'

[Paul215]

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...

100% what happened to me a while ago. I put on a new decalgirl skin and go out for the first flight. Same problems: red zero altitude and when hit RTH sparky starts rising. I was over 300' at this moment. I also tried every setting to get my spark down. After reaching 0% battery the sparks came down slowly. The last 10' were free fall but I was able to catch it. No damage!
First I thought it was because the high air moisture (same affect like fog) but at my next test (dry weather) the problem was not away. So I take a look at the bottom sensors and they were defently free. But I cut out the whole foil between the rubber bumpers AND..... Problem is gone! Maybe the foil was to shiny for the infrared sensors.

Edit: Like this

 

[nilanjan118]

100% what happened to me a while ago. I put on a new decalgirl skin and go out for the first flight. Same problems: red zero altitude and when hit RTH sparky starts rising. I was over 300' at this moment. I also tried every setting to get my spark down.

Did you try to pull the left stick completely down and hold it in that position? It should have made the AC go to landing mode and lose altitude.

 

[Paul215]

Did you try to pull the left stick completely down and hold it in that position? It should have made the AC go to landing mode and lose altitude.

Yes I tried. When I pull the stick down the camera starts looking forward and remote was beebing. But I lost not much altitude. (Maybe 2-3m/minute). Before that I flew some minutes and when I got the battery warning I was still at 90m.

 

[jbhamel]

Well I flew the spark today and it was fine until about 25' then the ground sensor started fluctuating between 0 and 25' going off and on. I did have control of the bird and took it higher but the sensor kept giving false readouts and then it went straight up on its own until i was able to level it off by pulling down the left joystick. It never showed it was higher than 130' but is was plenty high and i did have full control at that point. I flew through batteries mostly staying close to the ground but when i went high i could always land it. There is definitely a problem with the bottom sensor but seeing that it is out of warranty i am not sure if i want to spend the money on it. I will say that it does fly well except for the sensor problem but that is not my idea of playing it safe.

 

[nilanjan118]

Well I flew the spark today and it was fine until about 25' then the ground sensor started fluctuating between 0 and 25' going off and on. I did have control of the bird and took it higher but the sensor kept giving false readouts and then it went straight up on its own until i was able to level it off by pulling down the left joystick. It never showed it was higher than 130' but is was plenty high and i did have full control at that point. I flew through batteries mostly staying close to the ground but when i went high i could always land it. There is definitely a problem with the bottom sensor but seeing that it is out of warranty i am not sure if i want to spend the money on it. I will say that it does fly well except for the sensor problem but that is not my idea of playing it safe.

Yes, you have a faulty bottom sensor which is sensing ground or an obstacle even at altitudes where it is not supposed to. The AC going up on its own is normal in such circumstances. Also the altitude display flickers between IMU altitude and VPS altitude giving you absurd outputs. One way to avoid such erratic behavior is to turn off the bottom sensors. Now the official Go4 app doesn't have this option for the Spark but I have heard that you can turn off the sensors by using Litchi app. I don't have any experience with using Litchi but if I recall correctly, I remember reading in some old thread that it is possible to use Litchi app to just turn off the bottom sensors and then fly with Go4 app. Of course when you do so, you will lose the damping effect of the AC coming down while landing and should be very careful not to cause a hard landing or crash. If you do not want to spend money on repair, you can at least invest $25 on an app which will solve your problem and also give you a handful of new features as well.

 

[Paul215]

Another idea: DJIs new Pilot app. Its created for the enterprise drones but I read that some forum members successfully used it with the spark. And there is a option to turn off the sensor. I haven't tried it so be careful. But maybe its worth a try.

 

[jbhamel]

Yes, you have a faulty bottom sensor which is sensing ground or an obstacle even at altitudes where it is not supposed to. The AC going up on its own is normal in such circumstances. Also the altitude display flickers between IMU altitude and VPS altitude giving you absurd outputs. One way to avoid such erratic behavior is to turn off the bottom sensors. Now the official Go4 app doesn't have this option for the Spark but I have heard that you can turn off the sensors by using Litchi app. I don't have any experience with using Litchi but if I recall correctly, I remember reading in some old thread that it is possible to use Litchi app to just turn off the bottom sensors and then fly with Go4 app. Of course when you do so, you will lose the damping effect of the AC coming down while landing and should be very careful not to cause a hard landing or crash. If you do not want to spend money on repair, you can at least invest $25 on an app which will solve your problem and also give you a handful of new features as well.

Thanks for the idea! It really does still fly like a champ!

 

[sgrinavi]

Thanks for the idea! It really does still fly like a champ!

Don't you have a warranty?

 

[jbhamel]

Yes, you have a faulty bottom sensor which is sensing ground or an obstacle even at altitudes where it is not supposed to. The AC going up on its own is normal in such circumstances. Also the altitude display flickers between IMU altitude and VPS altitude giving you absurd outputs. One way to avoid such erratic behavior is to turn off the bottom sensors. Now the official Go4 app doesn't have this option for the Spark but I have heard that you can turn off the sensors by using Litchi app. I don't have any experience with using Litchi but if I recall correctly, I remember reading in some old thread that it is possible to use Litchi app to just turn off the bottom sensors and then fly with Go4 app. Of course when you do so, you will lose the damping effect of the AC coming down while landing and should be very careful not to cause a hard landing or crash. If you do not want to spend money on repair, you can at least invest $25 on an app which will solve your problem and also give you a handful of new features as well.

Thanks for the idea! It really does still fly like a champ

Don't you have a warranty?

Had?

 

[hiflyer]

Sorry to hear you're still having problems..It's just no fun to fly with out the bottom sensor.
you might just have to bite the bullet and send it in. I think there is a list of the prices on parts and if they change it out it might not be too expensive. DJI makes is super easy to send it in. They send a mailer and you pack it up and drop it off.