What happens if you shut down or lose connection to DJI Spark's controller in mid-flight? In this video, we go over Return to Home (RTH) feature of the DJI Spark and what happens if you turn a drone controller off in flight or your Spark loses connection with its controller.

This video is a 2 part series because I start to encounter anomalies while Returning to Home. This gets me curious in trying many different scenarios and turns into a full blown test.

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Joe thanks for the video

Tviscomi Posted at 2017-7-11 03:49
Joe thanks for the video

You're welcome. I hope this helps alot of people. And I want to be the first to say this video is to raise awareness and not slam DJI.

I appreciate the effort you've put forthright, and hopefully it will be helpful to DJI for firmware fixes.

I do too. Maybe they will see this.

Hi, sorry but I think your Spark behavior seems normal to me and following the manual. I think I can answer your 2 questions at the end of the clip:
1. First to anwer why it did not land after you pushed "Return to home", DJI said clearly in the manual page 15, point 5 of Failsafe RTH:"The aircraft will hover 0.3m above ground and wait for confirmation from the user.The aircraft will land and stop its motors after user confirmation".
2. To answer why it did not return to the home point but landed immediately. Because, if you see the screenshot I took from your clip below, you did not enable "RTH at current altitude", and again, in the manual, page 15, point 4:  "Note: if RTH at current altitude is disabled in DJI GO 4, the aircraft will land automatically when the aircraft is between 3m and 20m from the homepoint" (I've checked that your aricraft was 27ft ~8m from homepoint).

For more details in point 2 above, I understand it is quite confusing when DJI used the word "land" at point 4, but I believe they meant "descend". Because If you look at the whole Procedure, they listed the steps by steps, and the aircraft will land at step 5 only user confirm, or else will descend and hover at 0.3m.

So... I think there is no problem to fix here and hope my explanation helps.

Phuong Do Posted at 2017-7-12 04:08
Hi, sorry but I think your Spark behavior seems normal to me and following the manual. I think I can answer your 2 questions at the end of the clip:
1. First to anwer why it did not land after you pushed "Return to home", DJI said clearly in the manual page 15, point 5 of Failsafe RTH:"The aircraft will hover 0.3m above ground and wait for confirmation from the user.The aircraft will land and stop its motors after user confirmation".
2. To answer why it did not return to the home point but landed immediately. Because, if you see the screenshot I took from your clip below, you did not enable "RTH at current altitude", and again, in the manual, page 15, point 4:  "Note: if RTH at current altitude is disabled in DJI GO 4, the aircraft will land automatically when the aircraft is between 3m and 20m from the homepoint" (I've checked that your aricraft was 27ft ~8m from homepoint).

I appreciate your comment but if you are in a return to home situation something has gone wrong. Why should it be standard to have the drone hover in place? What if complete connection is lost? No way to swipe and have the spark land?

JoeCec Posted at 2017-7-12 04:48
I appreciate your comment but if you are in a return to home situation something has gone wrong. Why should it be standard to have the drone hover in place? What if complete connection is lost? No way to swipe and have the spark land?

I think you got a point there. However, as you spotted out in the part 1, GPS landing is not 100% exactly the same spot it takes off (For my case, sometimes it is 0.3 to 0.5m away from the original point). Therefore, let say you are closed to a lake, then the connection lost, you would like it hover above the water rather than landing to the water, and since it is hovering 0.3m above the water, you can come to pick it by hand and stop it (in case you don't know, grab it and turn it upside down the motors will stop immediately) even if the connection lost.
That just my opinion.

Phuong Do Posted at 2017-7-12 05:10
I think you got a point there. However, as you spotted out in the part 1, GPS landing is not 100% exactly the same spot it takes off (For my case, sometimes it is 0.3 to 0.5m away from the original point). Therefore, let say you are closed to a lake, then the connection lost, you would like it hover above the water rather than landing to the water, and since it is hovering 0.3m above the water, you can come to pick it by hand and stop it (in case you don't know, grab it and turn it upside down the motors will stop immediately) even if the connection lost.
That just my opinion.

I understand the water bit but it adds risk to hand catch a disconnected drone still in flight... DJI markets to a beginner level crowd and i wouldn't trust a newbie walking up and grabbing it. Plus what if downward vision positing is activated and the drone rises as you're trying to catch it? All of this is hypothetical, but should be taken into consideration I think..

well this is my first post on the forum and i am a new Spark owner, still waiting to get my hand on the RC, the video by JoeCec got me really concerned but thankfully the answer by Phuong Do clarifies it all and it really makes sense

Joe is comparing the Spark to his Mavic but in reality the default setup of the Spark differs from the Mavic and for a good reason, remember all videos advising you to disable RTH when attempting to fly the Mavic indoors? well the Spark designed/advertised to be used indoors and outdoors, hence the whole concept of the Spark

now notice the setup from the manual description and confirmed by Joe's video, if RTH is at current altitude:

- if RTH at current altitude is enabled: The Spark will return to its home point at current altitude if within 3 to 20 meters from home point
- if RTH at current altitude is disabled: The Spark will land immediately if within 3 to 20 meters from home point

so within 3 to 20 meters you have no way to force the Spark to go up the RTH altitude, this is clearly to prevent new users using their Spark indoors from hitting the ceiling and bypassing any need to manually disable RTH like you do on the mavic!

as for the hovering, well its clearly another failsafe specific to the characteristics of the spark, its not as accurate as the mavic in its landing and it's intended to be used by less experienced pilots than the mavic owners, so having it hover in place until you take action will prevent it from dropping over something or water during RTH

and one more thing, when it hovers in place after RTH, once battery is critically low it will land automatically anyway, there is no danger of the Spark crashing in this situation

Mavic owners should still read the Spark manual I guess...

JoeCec Posted at 2017-7-12 05:11
I understand the water bit but it adds risk to hand catch a disconnected drone still in flight... DJI markets to a beginner level crowd and i wouldn't trust a newbie walking up and grabbing it. Plus what if downward vision positing is activated and the drone rises as you're trying to catch it? All of this is hypothetical, but should be taken into consideration I think..

Hi, sorry I did not make myself clear, catching the drone and turn it upside down is just one of the trick.
I believe if you lost connection, restart the controller and/or restart the app should reconnect the aircraft and then you can manually land it. I think that is the most "official" way to land
Still, Spark works exactly similar to how they said in manual, so I doubt DJI would change anything to this. Let see if DJI got anything to say

Phuong Do Posted at 2017-7-12 05:51
Hi, sorry I did not make myself clear, catching the drone and turn it upside down is just one of the trick.
I believe if you lost connection, restart the controller and/or restart the app should reconnect the aircraft and then you can manually land it. I think that is the most "official" way to land
Still, Spark works exactly similar to how they said in manual, so I doubt DJI would change anything to this. Let see if DJI got anything to say

I completely understand the perfect world scenario, but this is by far not a perfect world. The manual can say whatever it wants but I just thought it interesting some of the characteristics that I have observed. I love DJI drones and I love flying. I would be interested to hear what they have to say. I am not a DJI basher by any means, but do think the algorithms could be tweaked just a little.

djiuser_gnHsAtB Posted at 2017-7-12 05:44
well this is my first post on the forum and i am a new Spark owner, still waiting to get my hand on the RC, the video by JoeCec got me really concerned but thankfully the answer by Phuong Do clarifies it all and it really makes sense

Joe is comparing the Spark to his Mavic but in reality the default setup of the Spark differs from the Mavic and for a good reason, remember all videos advising you to disable RTH when attempting to fly the Mavic indoors? well the Spark designed/advertised to be used indoors and outdoors, hence the whole concept of the Spark

No comparisons were made between the Mavic and Spark. I stated my Mavic and Inspire 2 were more accurate and more reliable during the same tests.  

JoeCec Posted at 2017-7-12 17:37
No comparisons were made between the Mavic and Spark. I stated my Mavic and Inspire 2 were more accurate and more reliable during the same tests.

still the behavious is exactly as described in the manual (Except the EMI part)

if RTH at current altitude is disabled: the craft will descend and hover in place with 3 to 20m, if RTH at current altitude is enabled: it will come back to home point and hover above landing point within 3 to 20m

I understand everyone thinks it's doing what the manual says but why hover when RTH is active. RTH is for when things go wrong and if something does go wrong I want my equipment on the ground safe and sound. These videos were created to raise awareness. I don't care about flying indoors either, I think the spark is too unstable for that with the sensors being low quality, and beating the ever living out of the furniture. The only benefit I see for having the Spark fly indoors is for orientation purposes and getting familiar with a drone. No acro or speed mode smooth stable consistent practice with nose in and tail in hover. Get familiar with the basics and comfortable with seeing it up off the ground. That's all I see indoor flying to be and maybe graduate into flying in a gym or something. That's it then you take it outside and you start to discover there's a world of interference and the sensors are susceptible to it and lost connection.

DJI you are making it to dang confusing for beginners. You have to hold your right arm above your head in stable condition while flying the Spark at a 45 degree angle adjacent to the tangent of the curvature of the earth......

I know a majority of Spark owners are new and want to jump on the DJI band wagon and say because it's in the manual it must be true, but this is simple not so. I am a huge fan of DJI products, but in my opinion I believe there should be a few modifications to the Spark if there is a second gen and at least a Firmware upgrade with better algorithms.

Good test Joe, good job.

I do think phuong and Hamid have it right, it may be from using the Mavic some confusion.

There seems to be a problem with loss of RC. Have you tried it without phone.

Thank that help a lot

Great info presented here - thanks