Litchi autonomous flight: lost my bird

You can prevent that by providing an appropriate "end-of-mission" action.

I saw that but I was worried that if I changed it to "Hover" then if something happened that caused my bird to lose contact with the RC then it would just hover in place until the battery became low and then land. I know that is not supposed to happen in that scenario but I figured better safe than sorry. No matter what I want it to come home. :)
 
In my case the inadvertent touch became the last waypoint in the mission. The point was a long distance away. I lost contact before it reached it. I presume the battery became critically low either on the way there or on the way back home at which point it attempted to land. Adding a lock function is a simple change that would help to prevent this kind of thing. Of course now that I know, I'll never make that mistake again!

Out of curiosity–not being critical–what were you focused on when your bird began deviating from the mission? Could you see it? Which screen were you watching? The map/mission or the camera?

I always tense up a bit when flying waypoint missions and keep my left trigger finger on the RC mode switch in case I see something I don't like. (It'll hover when you flick it back.)

Thanks,

Tony
 
OK, here's what happened.

This is a longer post, but wanted to follow up and share the loss, and eventual recovery, of my drone while it was on an autonomous mission using Litchi. Hopefully someone will find this helpful and reassuring.

In brief, I carefully planned the route online using the Litchi Mission Hub and used Google Maps and elevation charts to plan the waypoints. The flight was up a steep hillside to a fire road at the top of a ridge, which was at about the max altitude the Phantom can fly. (Note: the Phantom was always less than 300 feet over the ground at each waypoint). While I planned it for late afternoon/evening, it was nearly dark when I took off. I'm very familiar with the area though and planned to fly it up and back on a trail I regularly hike. The Litchi Mission Hub calculated the flight to be 2 miles and 11 minutes flight time. With such a steep climb, I left plenty of room for ascent and descent. All seemed good. (See below for mission plan with waypoints).
View attachment 43112

At the takeoff point, I did the usual startup procedure, setting up the camera using DJI Go. On takeoff, I turned on Litchi and once it was in the air sent it on its autonomous mission. It began heading off to the first waypoint.

Within a few minutes, I lost signal and got the big red "Disconnected" message at the top of the app. I knew the Phantom had the waypoints uploaded and that it would fly without being connected, and there was a hill blocking a direct clear path between me and the Phantom. I checked my watch and expected it home at around 11 minutes so I waited as patiently as I could, giving it a max of 20 before I went hiking.

After 10 minutes there was no sign of it. After 15 I was convinced something had gone wrong, so I grabbed my flashlight and started up the (steep) hill, controller in hand. I was hoping it would connect once I got within line-of-sight as long as I had some battery left. Just a few hundred yards up the hill, I looked to the west and high up in the sky (it looked like it was up at least 800 feet, maybe much higher - remember it's night time) and far away I spotted the drone's flashing lights - wayyyy up there. It appeared to be heading far past the takeoff point (and final mission waypoint) but I was hopeful it was on the way back. I quickly ran down the hill to the launch point, and tried frantically to reconnect with the Phantom. I restarted Litchi, tried DJI Go, and restarted the remote, all to no avail. While I was doing all of this I lost sight of the bird and assumed it ran out of battery and auto-landed in a heavily wooded area a long way distant. From where I last saw it in the air I knew it was long gone.

I came home and spent hours analyzing my mission plan, checked the waypoints carefully, and reviewing the software manuals. I could not figure out why it would fly the full mission and miss the last waypoint. Since it did go up the ridge 1600 feet, I figured it was still up at that altitude when it made the last pass overhead on the way back until in ran out of battery and landed itself miles away.

This morning I got a phone call - someone found the drone (with my phone number on it, which is the only reason I got it back). I was very surprised that someone could have found it in that forested area miles away that is also private property. Well, he didn't find it there. He found it on the hiking trail I was flying up. He said it was about 3/4 the way to the top of the ridge, and it was laying upside-down.

I downloaded the logs and video to figure out what happened. Since it was nighttime, the video didn't show much, but between the flight logs, the video I could see, and in reviewing the mission waypoints I found out what happened. In short, I ran into the hillside.

View attachment 43113
I set each waypoint altitude at least 150 feet above the ground level indicted by Google Maps, and most at 200 feet higher, just to be safe. Well, the hill isn't a smooth, even rise up to the top - there are outcroppings, ridges, trees, and valleys that rise above and drop below the elevation at each waypoint. While my altitude at waypoint 4 had plenty of ground clearance, I did not climb rapidly enough to clear a ridge between waypoints 4 and 5. The Phantom hit the ground and there she sat until it was found today. This also explains why I could not reconnect the controller to the Phantom when it was flying overhead – because it wasn't, in fact, flying overhead.

What about the phantom flying way up overhead past the final waypoint?

Obviously this was a misidentification on my part, in the "let's jump to conclusions" department. Since it was in the same area and roughly on the same heading I had plotted, I assumed it was my phantom. This is outside a major metro area and there are flights (far) overhead all the time, so that's likely what I spotted, and at night all I had were steadily moving lights way up there with no other points to reference. Given my set course and all that had taken place, I assumed it was my Phantom and that's what I immediately jumped to.

That's it. Again, this is long-winded and perhaps slightly embarrassing, but I think that's what communities like this are for - so we can all learn from each other. If anyone has any questions I'm glad to jump back in and answer.

And if you haven't done it already, post your phone number on the outside of your drone! That's the only reason I got it back and figured all of this out.

Thanks and fly safe.
Ok, so maybe I'm *not* kidding myself by putting my number on mine, too.

Thanks for sharing, and knowing when it is op error as well. We can all learn from this. I hope your bird is still flyable!

Sent from my SM-N920T using PhantomPilots mobile app
 
Thanks to everyone for the ideas, thoughts, and feedback.

To be clear, I think many instances of lost Phantoms is in fact operator error and I'm not ruling that out. I consider myself a new pilot with about 50 flights, and although I try to be thorough, it is very possible that my own handiwork or some unknown environmental features came into play. I am also new to Litchi and although I read all the documentation and practiced with it, there may be something I missed.

I do have my phone number on the drone and my fingers are crossed that a hiker or someone will find it - we have sunny and 60 degree temps here right now so it's a possibility. If I recover it I will be sure to share all the flight data and information I have for the good of our community, and so we can all learn from others.
Richie has a function called find my drone look through the app I believe it is on the general tab in settings it should show the last known location of the Drone
 
Lost my drone today... at the third waypoint, the Litchi app disconnected. RTH did not work, giving me a failure to connect to server cue. After a 3 hour needle in a haystack search following the track... that puppy is gone (DJI Phantom 3 Pro)... I just can't trust the Litchi software after that experience.

The Litchi software was the latest version and the DJI firmware was the latest Phantom 3 Professional Firmware v1.9.60. Total bummer... was recording a 35 acre piece of property for real estate purposes.
View attachment 58552
Check in litchi General tab in settings scroll down use the find my aircraft button it will show the last known location
 
Opinions and actual experiences do vary... The Android version of the Litchi app cannot record the phone/tablet screen as the iOS version apparently can... a very significant and potentially useful tool omitted in my view.
Use AZ screen recorder
 
Dont think its a good idea to have Litchi and DJi go on the same phone or tablet. I have an old galaxy s3 which I use for DJi app without a sim card in it which works fine, and a newer Galaxy s5 neo for the Litchi app which also works well. I have heard that the 2 apps on the same phone or tablet can cause problems...

Sent from my GT-P5110 using PhantomPilots mobile app
 
it is probably irrelevant in this case but I just wanted to point out that the failsafe RTH does not work in 3rd party apps when the controller loses connection, it is a bug recently discovered by Autoflightlogic (Autopilot app) and wont be fixed until DJI updates their firmware.

Home - Autoflight Logic
Concerning RTH in autonomous flight. I

I have been doing some testing in this very area. I do not have enough confidence in Litchi to use/test it, but have been flying Ultimate Flight. I went yesterday to a huge park with many open spacs so that if something happened, there would be plenty of emergency/unplanned landing places.

I set up a small square mission with 4 waypoints and turned off my Remote Controller midflight. My little bird continued flying it's mission. Then I turned the RC back on and reconnected with the bird almost immediatly. And it continued on the mission, I then did a RTH and it abandoned the mission and came home.
 
Dont think its a good idea to have Litchi and DJi go on the same phone or tablet. I have an old galaxy s3 which I use for DJi app without a sim card in it which works fine, and a newer Galaxy s5 neo for the Litchi app which also works well. I have heard that the 2 apps on the same phone or tablet can cause problems...

Sent from my GT-P5110 using PhantomPilots mobile app
I believe Litchi tells you that on Samsungs they can not coexist.
 
I've had both the DJI Go & Litchi apps installed on both my Galaxy S5 & Nexus 7 for quite awhile now without any problems. As long as you don't have your device automatically connect to either app, but instead choose which app to use every time you connect to your bird, you should be fine. You should also be going into your "recents" on your Android device and clearing all before every flight. This way you know for sure the other app isn't running in the background.

S5 tap'n
 
I believe Litchi tells you that on Samsungs they can not coexist.

Dont think its a good idea to have Litchi and DJi go on the same phone or tablet. I have an old galaxy s3 which I use for DJi app without a sim card in it which works fine, and a newer Galaxy s5 neo for the Litchi app which also works well. I have heard that the 2 apps on the same phone or tablet can cause problems...

Sent from my GT-P5110 using PhantomPilots mobile app
I have flown hundreds of missions and hours of flight with no problem at all. You can't have them running at the same time but there are several settings in dji go that don't exist in Litchi. Either force close DJI go or back all the way out until you get confirmation it's closing.
 
I've had both the DJI Go & Litchi apps installed on both my Galaxy S5 & Nexus 7 for quite awhile now without any problems. As long as you don't have your device automatically connect to either app, but instead choose which app to use every time you connect to your bird, you should be fine. You should also be going into your "recents" on your Android device and clearing all before every flight. This way you know for sure the other app isn't running in the background.

S5 tap'n
You posted just before me. While we agree, I disagree with one point. I think DJI Go needs to be force closed or backed out completely to where a toast notification tells you it is closing. In my experience, I have flown in the morning and when done, swiped away DJI Go. Later that day had experienced bad battery drain and upon inspection it was DJI Go using my battery all day. This happened several times. Bottom line, a simple swipe in recents doesn't close DJI Go.

Sent from my SM-N920K using PhantomPilots mobile app
 
You posted just before me. While we agree, I disagree with one point. I think DJI Go needs to be force closed or backed out completely to where a toast notification tells you it is closing. In my experience, I have flown in the morning and when done, swiped away DJI Go. Later that day had experienced bad battery drain and upon inspection it was DJI Go using my battery all day. This happened several times. Bottom line, a simple swipe in recents doesn't close DJI Go.

Sent from my SM-N920K using PhantomPilots mobile app
Havent flown on this phone, only opened Go on it last night to grab some pics off the bird. Not 3 minutes ago, right as i was opening the app to read this, i got a popup notification that dji go had stopped working. Really? Cause it was supposed to stop working last night.

So I'm with jiggyb21, force close to be sure.

Sent from my SM-N920T using PhantomPilots mobile app
 

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