So I flew my new Spark for the third time this afternoon and had my first panic moment.  I was hovering at around 80m when i saw a police chopper come buzzing over a nearby hill.  I wouldn't say they were very close, but my instinct told me to descend and play it safe.  As the chopper got closer I suddenly found that the Spark was no longer responding.  I panicked and pressed return to home.  The Spark began to descend, however it was drifing away from me and the "home" that had been set by about 20m and growing.  I looked at my iphone to see that it was now registering as "disconnected". When I looked back up the little guy was making contact with a tree branch and began it's crash.  It hit a couple of more branches on the way down and actually landed pretty safley.  Luckily I don't see any damage.
Now I'm trying to figure out why this happened.  I calibrated the compass before takeoff.  Conditions were super clear and calm.  I've flown in that area, at much dreater distances and altitudes with no issue.  Do police helecopters have any kind of scrambling devices they employ?
I tried flying one more time and after takeoff the controlls were totally unresposive even though it was showing a solid connection.  After I plucked the spark out of the hair with my hand, I shut eveything down, including the app and conroller, changed the battery, and everything worked fine after that.
Any input from you guys would be helpful.  It sure freaked me out.

Thanks.

-The Spark began to descend, however it was drifing away from me and the "home" that had been set by about 20m and growing.  I looked at my iphone to see that it was now registering as "disconnected"-

In my understanding, 'disconnected' means mostly the App, not the RC
Did you try to stear it yourself?
b/c it also looks like it went into Atti, which means 'blown in the wind'

Spark never descends on RTH , this looks like you hit landing mistakenly instead of RTH , using the app for RTH it’s very easy to hit landing.

You could put up your log to see exactly what happened just click on link below and follow instructions. Come back here and post your link

http://www.phantomhelp.com/LogViewer/Upload/

i had similar experience with my mavic but i think i figured it out thanks to a friend so ill share the theory.  i imagine that maybe radar system aboard the chopper may have "jammed" the drone.   i doubt it was intentional or protective feature to keep drones away in nature.  radar systems on police and military choppers tend to be very powerful and have very wide bands of coverage, usually 5.5-5.8Ghz signals get disrupted by them much easier because that's typical long range radar system frequencies.  however they are powerful enough that they can disrupt 2.4Ghz and lower as well by congesting/saturating the near by spectrum.

as for why your spark landed or descended, i'm going with, you accidently tapped land button on screen which is close to home, panic situation, it happens.  RTH will always rise if you are below the alt picked and if you are above alt. it will just fly back at that height.

hallmark007 Posted at 2017-12-3 17:44
Spark never descends on RTH , this looks like you hit landing mistakenly instead of RTH , using the app for RTH it’s very easy to hit landing.

You could put up your log to see exactly what happened just click on link below and follow instructions. Come back here and post your link

When I read your suggestion I opened up the app and looked at where the two commands fall on the screen and realize it's totally possible that this is what I mistakenly did.

Telecopter Posted at 2017-12-3 18:21
When I read your suggestion I opened up the app and looked at where the two commands fall on the screen and realize it's totally possible that this is what I mistakenly did.

It’s a mistake many have made, it seems impossible to stop it once you initiate but if you switch to sport mode this can stop landing command it’s not ideal but can work, really pause or left stick up should be the way to cancel landing, hopefully new firmware will sort this as it can be a real problem over water.

djiuser_MP6tU5Q Posted at 2017-12-3 18:11
i had similar experience with my mavic but i think i figured it out thanks to a friend so ill share the theory.  i imagine that maybe radar system aboard the chopper may have "jammed" the drone.   i doubt it was intentional or protective feature to keep drones away in nature.  radar systems on police and military choppers tend to be very powerful and have very wide bands of coverage, usually 5.5-5.8Ghz signals get disrupted by them much easier because that's typical long range radar system frequencies.  however they are powerful enough that they can disrupt 2.4Ghz and lower as well by congesting/saturating the near by spectrum.

as for why your spark landed or descended, i'm going with, you accidently tapped land button on screen which is close to home, panic situation, it happens.  RTH will always rise if you are below the alt picked and if you are above alt. it will just fly back at that height.

ya thats what i was thinking Chopper interference if not we will probably see it in the near future  

Telecopter Posted at 2017-12-3 18:21
When I read your suggestion I opened up the app and looked at where the two commands fall on the screen and realize it's totally possible that this is what I mistakenly did.

Hi, sir. Please choose a wide place without interference for flight. Please learn about the local regulations and follow the rules. Any error message in the app?

My Spark will disconnect temporarily when the Hospital Helicopter flies over/near me when I'm flying my Spark. I do not try to land while they are flying over. I lower to a safe altitude, wait until they are out of range, reconnect the Spark and then land. Just don't freak out next time. If you are out of their flight path just wait where you are until they are gone.