New to Litchi - I lost my drone :(

[ExcitingHeadgear]

I did realize that but I was only flying a quick test 237m / 2 min mission so thought it would be fine.

Safest policy is to never fly on a battery that isn't full, especially a mission.

Unfortunately you use about 10% battery to get ready for takeoff and get into the air, and about 10% battery to land safely, so that's 20% taken with 6% battery left for flight time. Combine that with a windy day and a long flight path, recipe for disaster unfortunately.

 

[Tribar]

I would like to know why it went from waypoints mode to GPS mode, then to atti mode. If I inadvertently hit a joystick, would that immediately stop the mission and put it in atti mode?

Most likely magnetic interference and/or compass not calibrated.

 

[RotorWash]

I would like to know why it went from waypoints mode to GPS mode, then to atti mode. If I inadvertently hit a joystick, would that immediately stop the mission and put it in atti mode?

Log files (.txt/.csv) such as above won't give you a definitive answer as they don't contain enough data. It may be possible to find out by examining the .dat log file but that's on the bird itself. There's also a limited version of the .dat log file on the mobile device but I don't think one is created when Litchi is used. In any event you would need someone with more experience than myself to properly examine it. Even then sometimes there is no definitive answer as to why.

I did notice from the attitude indicator that the bird seemed to be doing some heavy rolling from the time waypoints took over and continued doing so going across the street to WP1 and then soon after went into ATTI mode. This rolling was probably caused by the wind hitting the bird once it got above the treeline. I'm no expert on the matter but two possibilities I can think of would be either a malfunction where the IMU and the GPS disagree about velocity which the wind may have played a factor or a compass error due to a launch site that was magnetically distorted in some way. Your stick inputs seemed minimal and shouldn't have been an issue.

From the time you turned the drone on to the time you took off was it near any metal that might throw off the compass? Even something small like a raised nail on a deck can effect the compass if close enough. I don't see any of the standard compass/yaw/speed errors in the log but as I'm newish to Litchi myself I'm not sure if Litchi records that data, maybe one of the veteran Litchi pilots reading this will know. Besides the .csv log, Litchi also creates a .txt log that is located in Android with the path: \DJI\com.aryuthere.visionplus\FlightRecord\. You could try posting that to the Phantomhelp LogViewer just to see if there is any other info in it.

 

[Tonyf85]

I launched the Spark from a 6ft plastic folding table that you might find at Home Depot. The underside of the table does have a metal frame, so that could have effected the compass I guess. I will look for the additional log file you mentioned.

 

[Bob Johnston]

Log files (.txt/.csv) such as above won't give you a definitive answer as they don't contain enough data. It may be possible to find out by examining the .dat log file but that's on the bird itself. There's also a limited version of the .dat log file on the mobile device but I don't think one is created when Litchi is used. In any event you would need someone with more experience than myself to properly examine it. Even then sometimes there is no definitive answer as to why.

I did notice from the attitude indicator that the bird seemed to be doing some heavy rolling from the time waypoints took over and continued doing so going across the street to WP1 and then soon after went into ATTI mode. This rolling was probably caused by the wind hitting the bird once it got above the treeline. I'm no expert on the matter but two possibilities I can think of would be either a malfunction where the IMU and the GPS disagree about velocity which the wind may have played a factor or a compass error due to a launch site that was magnetically distorted in some way. Your stick inputs seemed minimal and shouldn't have been an issue.

From the time you turned the drone on to the time you took off was it near any metal that might throw off the compass? Even something small like a raised nail on a deck can effect the compass if close enough. I don't see any of the standard compass/yaw/speed errors in the log but as I'm newish to Litchi myself I'm not sure if Litchi records that data, maybe one of the veteran Litchi pilots reading this will know. Besides the .csv log, Litchi also creates a .txt log that is located in Android with the path: \DJI\com.aryuthere.visionplus\FlightRecord\. You could try posting that to the Phantomhelp LogViewer just to see if there is any other info in it.

A log file is created on the mobile device in Litchi folder with data for as long as the bird is still receiving data. For longer auto flights there will be a gap once out of data range until the bird returns into data range.

 

[Bob Johnston]

I launched the Spark from a 6ft plastic folding table that you might find at Home Depot. The underside of the table does have a metal frame, so that could have effected the compass I guess. I will look for the additional log file you mentioned.

IF the tabel frame is steel , then yes that could create compass issues. Most frames are aluminum to lighten table weight. Alumininm does not affect compass. I've launched many time form al docks and boats without problems.

 

[Bob Johnston]

Also, a lot depends on what your settings were in Litchi and if smart return was on and what our critical battery settings were. that info would make a difference as well.

 

[RotorWash]

A log file is created on the mobile device in Litchi folder with data for as long as the bird is still receiving data. For longer auto flights there will be a gap once out of data range until the bird returns into data range.

Thanks Bob, when you say gap do you mean within the same log file or does another log file begin?

 

[RotorWash]

I launched the Spark from a 6ft plastic folding table that you might find at Home Depot. The underside of the table does have a metal frame, so that could have effected the compass I guess. I will look for the additional log file you mentioned.

Any chance of the Spark being stored by anything magnetic before taking this flight?

 

[Bob Johnston]

Thanks Bob, when you say gap do you mean within the same log file or does another log file begin?

Same log file. I've flown many waypoint missions, and they all have a gap once drone is out of telemetry range and restarts in the same file when they come back into telemetry range.

 

[Bob Johnston]

If compass was an issue, a compass error should have shown up i the log file. Never do a compass recal unless advised to do so by software.

 

[Tonyf85]

Any chance of the Spark being stored by anything magnetic before taking this flight?

No not that I'm aware of. I store it in its case when not in use.

 

[Tonyf85]

If compass was an issue, a compass error should have shown up i the log file. Never do a compass recal unless advised to do so by software.

Is this true and recommended not to calibrate compass? I thought maybe the issue I had with it going tinto atti mode, was that i did not calibrate the compass prior to launch.

 

[Bob Johnston]

According to the FAA UAS Data Map you are in a Class C no fly zone unless you have LAANC permission to do so. Your awfully close to the no fly part of the C airspace(0 altitude) and as these are not rock hard zones, this may have been what happened to you. These restrictions have just been instituted within the last year, so with your flying hiatus you probably missed these changes. If you open up GO4 and check the map while on GPS, you should see these changes. Litchi does not inform you of this in the app. In my case it wouldn't let me start the engines at first. After trying several times it started and as it moved forward it began landing. As I was over water, I just happened to look up to see its decent and managed to pull it back into weeds n the shoreline. Failing to start, I opened Go 4, and sure enough, I was at the very end the zoned runway closure and Go4 would not let me start engines at all. .
Unfortunately, when the drone enters restricted airspace it apparently lands rather than hover and or return to home. A fact that has dismayed many who run afoul of it. I got lucky. I think you hit by your low battery, and/or the restricted zones, or any combination of them.
Sorry for your loss.

 

[Bob Johnston]

Is this true and recommended not to calibrate compass? I thought maybe the issue I had with it going into atti mode, was that i did not calibrate the compass prior to launch.

I've traveled 1200 miles from original calibration point whiteout having to re calibrate. Its well documented in these forums to only calibrate when told to . If compass error is shown in the app, move the drone and try another spot several. Then re calibrate if you still have the error.

 

[Tonyf85]

View attachment 12741
According to the FAA UAS Data Map you are in a Class C no fly zone unless you have LAANC permission to do so. Your awfully close to the no fly part of the C airspace(0 altitude) and as these are not rock hard zones, this may have been what happened to you. These restrictions have just been instituted within the last year, so with your flying hiatus you probably missed these changes. If you open up GO4 and check the map while on GPS, you should see these changes. Litchi does not inform you of this in the app. In my case it wouldn't let me start the engines at first. After trying several times it started and as it moved forward it began landing. As I was over water, I just happened to look up to see its decent and managed to pull it back into weeds n the shoreline. Failing to start, I opened Go 4, and sure enough, I was at the very end the zoned runway closure and Go4 would not let me start engines at all. .
Unfortunately, when the drone enters restricted airspace it apparently lands rather than hover and or return to home. A fact that has dismayed many who run afoul of it. I got lucky. I think you hit by your low battery, and/or the restricted zones, or any combination of them.
Sorry for your loss.

Thanks for the info. Thats an interesting map. Where can I access that map?

 

[Spark 317]

Thanks for the info. Thats an interesting map. Where can I access that map?

Here's the link.

ArcGIS Web Application

www.arcgis.com

.

Here's the map that pilots and Part 107 drone pilots use.

VFRMAP - Digital Aeronautical Charts

Online VFR and IFR aeronautical charts, Digital Airport / Facility Directory (AFD)

vfrmap.com

Quite a bit of difference.

 

[Tonyf85]

Thx. I see in your tagline that you use 'Loc8tor Tracker'. Do you have the tag attached to your Spark? how does that effect its flight/flight time?
I was thinking of attaching a 'Tile Mate' to my next drone to help find it if I lose it. It works with bluetooth (200 ft range). Is that feasible?

 

[Spark 317]

I haven't had to use it yet for a rescue mission, but have had played hide and seek with it. Seems to work.

I have mine mounted right on top dead center.

It's the black dot on my avatar.

 

[Spark 317]

Here's a better picture.