Crash on waypoint mission

jwilson · Monday at 11:40 PM

I was flying a series of out of signal range waypoint missions over train track and terminals under construction near my house. I was on my 8th iteration of these missions. The 7th flight was fine. Then the next flight, 8, the drone did not return. It's a Mavic 3 Pro. This happened on 2025-03-06 at 15:17. So I went to look for it, but I could connect to it with find my drone. So I left my contact information with the construction sites security guard.
The next Monday I printed out some flyers showing what my drone looked like, and the route it was flying. I took them to the security guard so he could post them around the construction site. When I did this, a construction worker came up to me and asked if I was looking for the broke drone. I said yes. He went away for 2 minutes, and came back with the drone in one hand and the battery in the other. The drone was heavily damaged with the camera/gimbal assembly missing and almost all the arms, motors and propellers damaged. The body of the drone seemed more less intact.
So I told DJI I found the drone and sent it back to China the next day, which I did. The sd card was in the drone but the video file was corrupted and wouldn't play. I copied it's contents to my computer, and sent it back to them with the drone.
I tried to use this video repair program called Stellar to repair the video files but it didn't work. Finally I tried to repair the 720p file, .LRF, and it worked. I could see the drone was way off course, and ended up hitting some construction equipment, even though obstacle avoidance should of been on. So the crash was not my fault. I told DJI this, and they escalated my case to a higher up, but she rejected my request for a discount because the drone was out of warranty. So I ended up spending $1,300 including shipping. They're unclear if they will repair it or send me a replacement unit. The replacement unit would only have a 90 day warranty.

Here are the videos of the crashed flight and the previous flight that didn't crash. I didn't move any waypoints, but did increase the speed from 22 mph to 30 mph. As far as I know that should not have changed the flight path.

Video where drone crashed.
Video train 7 last mission before crash.
Here's a picture of the waypoint mission. The crash occurred around waypoints 3 or 4.

Also some pictures of the crashed drone.

mavic3usa · Tuesday at 12:19 AM

Sorry but in my opinion, that waypoint flight is unsuitable for "out of signal range" missions. Much too risky to allow the drone to fly autonomous and without visual line of sight even with OA. I guess you found out the risks. The latest Mavic is a great drone but there's just too many variables to manage those tight tolerances even with repeated successful missions.

jaja6009 · Tuesday at 1:51 AM

Are you sure you did not change anything in the waypoint mission. Even with the drone's GPS inaccuracy of 1 to 5 meters or more in some cases, the flights are not lining up with each other at all. I have done waypoints with non-RTK drones and for the most part they are very, very similar.

If this is how you fly often, look into an RTK drone since they will be much more accurate and precise when arriving at each waypoint.

mavic3usa · Tuesday at 2:03 AM

Looks like they moved the equipment.

DoomMeister · Tuesday at 5:44 AM

@jwilson , was the speed in the first 7 flights set to 22mph, and then to 30mph for flight 8?

I believe waypoint missions with the Mavic 3 Pro do not fly straight between waypoints. They are done in a more cinematic curved flight path and speed of the flight can affect the path that is taken along the waypoints. Increasing the speed from 22mph to 30mph was a 36% change in speed and would have greatly affected the path.

More info in this post
Post in thread 'Waypoint flights, some questions.'
Waypoint flights, some questions.

jwilson · Tuesday at 6:14 AM

mavic3usa said:
Sorry but in my opinion, that waypoint flight is unsuitable for "out of signal range" missions. Much too risky to allow the drone to fly autonomous and without visual line of sight even with OA. I guess you found out the risks. The latest Mavic is a great drone but there's just too many variables to manage those tight tolerances even with repeated successful missions.

Well, I've had many hundreds of out of signal range waypoint missions, with only a few problems. One got lost completely, but DJI replaced it for free because it was in warranty. Two I had in Thailand hit thin guy wires holding up a high antenna and crashed. The second time that happened, I was able to use find my drone to recover the drone in a tree. The repair bill was only $50.
But this one seems very strange because it was so far off course.
They just shipped my replacement drone today, so I will test it more when I get it.
One thing is, I'm not sure obstacle avoidance is automatically switched on when you fly these missions. So from now on I will manually check it before every flight.
DJI says they will not help me determine the cause of this crash because it was out of warranty.
I flew my Mini 3 Pro looking for my crashed drone, so now I can't look at any waypoint missions.
I will go over to the construction site, and fly from there so I can maintain connection in case of any problems. I guess I won't experiment with the speed in the future. The default speed I use is 22 mph to give myself the best range.
Where i live, it's boring just flying my drone around the house. I don't have a car.

jwilson · Tuesday at 6:16 AM

jaja6009 said:
Are you sure you did not change anything in the waypoint mission. Even with the drone's GPS inaccuracy of 1 to 5 meters or more in some cases, the flights are not lining up with each other at all. I have done waypoints with non-RTK drones and for the most part they are very, very similar.

If this is how you fly often, look into an RTK drone since they will be much more accurate and precise when arriving at each waypoint.

I'm pretty sure, but I can't be positive until I get my Mavic 3 Pro back. They just shipped it today. Does DJI make a RTK drone, or is that an accessory?

jwilson · Tuesday at 6:17 AM

mavic3usa said:
Looks like they moved the equipment.

Not to me. It looks like it was in the same place. But that's something you always have to worry about.

jwilson · Tuesday at 9:59 AM

DoomMeister said:
Increasing the speed from 22mph to 30mph was a 36% change in speed and would have greatly affected the path.

I didn't know that and it could be the problem. I didn't think the speed would affect the path at all.

jwilson · Tuesday at 10:22 AM

DoomMeister said:
@jwilson , was the speed in the first 7 flights set to 22mph, and then to 30mph for flight 8?

I believe waypoint missions with the Mavic 3 Pro do not fly straight between waypoints. They are done in a more cinematic curved flight path and speed of the flight can affect the path that is taken along the waypoints. Increasing the speed from 22mph to 30mph was a 36% change in speed and would have greatly affected the path.

More info in this post
Post in thread 'Waypoint flights, some questions.'
Waypoint flights, some questions.

After watching both full flights, I can see the paths were very different between the two throughout the flights. . I will have to review the waypoint missions when I get my drone back to see if there's any explanation for this.

DoomMeister · Tuesday at 1:23 PM

jwilson said:
After watching both full flights, I can see the paths were very different between the two throughout the flights. . I will have to review the waypoint missions when I get my drone back to see if there's any explanation for this.

I fly a different brand of drone, but it behaves in the same manner during waypoint missions. Speed can greatly affect the path between waypoints as the programming is attempting to make as smooth s flight as possible for cinematic effect.

It is just like driving a vehicle at different speeds. The faster you go the more shallow turns have to be to avoid heavier centrifugal forces.

One thing to really watch for is changing altitude along the waypoint path. The curves automatically generated can be outside (higher/lower) the altitudes set by the waypoints.

jwilson · Tuesday at 9:28 PM

DoomMeister said:
I fly a different brand of drone, but it behaves in the same manner during waypoint missions. Speed can greatly affect the path between waypoints as the programming is attempting to make as smooth s flight as possible for cinematic effect.

It is just like driving a vehicle at different speeds. The faster you go the more shallow turns have to be to avoid heavier centrifugal forces.

One thing to really watch for is changing altitude along the waypoint path. The curves automatically generated can be outside (higher/lower) the altitudes set by the waypoints.

Yea, I found that out the hard way. I almost hit the ground when I was decending. I find you have to put three waypoints close together to avoid this.

jwilson · 2025-03-27T01:03:21-0400

Got replacement drone today. Charging batteries now.

Starz · 2025-03-27T07:16:57-0400

mavic3usa said:
Looks like they moved the equipment.

I didn’t see that occurred. Looks to me like two different flight paths.

jwilson · 2025-03-27T11:23:57-0400

After get the new drone, I could view the missions. Turns out they are different. I don't know if that was intentional or accidental. 8 is the one that crashed. Later I will upload the whole flights on YouTube so you can see them