Mystery flyaway: What happened?

[Edslittleworld]

Hello, I'm a reasonably experienced drone pilot without any crashes to my record. I've flown both Phantoms and Mavics for years. However, that dreaded event happened today.

I was flying around the craggy mountains of Southern Arizona. I was gently "barnstorming" the peaks of nearby mountains when I decided to fly thru a V-crack in the ridgeline. I had turned the Sport mode off and was just inching thru the V-crack (which was around 25-30 feet wide) around 800' elevation from me in the valley. The drone's relative elevation was around 25 feet high from the bottom of the V-crack. It was fairly breezy, but not too windy.

The Mavic was approximately 3000 feet away and I had good signal. I was also flying with the DJI goggles. Right as I passed thru the V-crack, I lost signal (also Weak GPS Signal on screen) and never regained it. I even tried the RTH button, but it never reconnected. Being that the drone was at 800' elevation from the launch point, I assume that the climbing mode didn't actuate when the internal RTH command was issued.

Also, I have been receiving a constant errors in my recent flights which said: "FORWARD SENSOR CALIBRATION ERROR".

My guess is that my Mavic crashed into a mountaintop upon return as it didn't climb and didn't have forward sensors (although Sport mode was off). I could not investigate the crash site as it was too steep and would require crossing restricted mining land. What else could have happened (See attached screen shot)?

 

[pixl]

What was your RTH elevation set at? If it was actually set lower than the climb you had just made, it would try to return home by going straight down, no?
I usually have my RTH height set around 250 feet. In your scenario it would go down until the ground sensors kicked in and likely just hover there until low battery forced a landing. By the sounds of it, it probably landed not far down the other side of that ridge.

 

[flightmike]

If your higher than your RTH altitude it will stay at that height and come home.
It will head in a direct line to the home point so if you were in the V it probably hit the side, especially if you said you had to go slow just to get through it.
Obstacle avoidance will not protect the sides.
To bad you can't get to it. I would say your out of luck. So sorry.

 

[tracer bullet]

If your higher than your RTH altitude it will stay at that height and come home.
It will head in a direct line to the home point so if you were in the V it probably hit the side, especially if you said you had to go slow just to get through it.
Obstacle avoidance will not protect the sides.
To bad you can't get to it. I would say your out of luck. So sorry.

^^^ Agreed to all the above. This is how RTH works and would be my guess as to what happened. Also sorry to hear it.

Mavic's RTH is a thing that seems simple but really has to be understood, and event he settings may need to be revised every time one goes out to fly. If nothing else, hopefully others can see how it went wrong here and learn.

 

[hookalakupua]

^^^^Everything the guys said above. Had the exact same thing happen to me. Lost signal behind a cliff wall in Scotland that was higher than my designated 400ft return height. Long story short, it auto landed and I miraculously found it an hour later! That's the reason I have now removed my RTH Height.

Maybe you could contact the mining sight as I'm almost certain you'd find it right there. Good luck!

 

[pixl]

Yup. You gotta remember that RTH climbs whatever height you specify AGL at the home point. You'd have to know the elevation difference in advance before leaving the home point plus add a margin of error in order for RTH to work as intended. It sounds like the MP worked as designed.

You may be able to get some insight about the "FORWARD SENSOR CALIBRATION ERROR" by uploading your flight log at at Airdata UAV - Flight Data Analysis for Drones , but it doesn't sound like it was a factor in the loss.

 

[Edslittleworld]

RECOVERED! It was a day-long odyssey to recover my drone starting with a 10 mile 4WD (low-range) drive to a good launch point, a 2 mile distant reconnaissance with my new drone, a "friendly" ride with the mining company security vehicle to the crash site and a pretty sketchy 30 minute hike off the side of a cliff.

I agree with what the above posters said. Plus, I found (believe it or not!) one of the forward sensor packing films on the ground...whoops! So, it was apparently the cause of the Forward Sensor Error. It hit hard enough on the mountain edge to eject the battery (never found), shatter the camera bubble and camera lens and bang up the front pretty good. Attached are the salvage photos.

 

[Stan1915]

RIP Mavic!

 

[MAvic_South_Oz]

Plus, I found (believe it or not!) one of the forward sensor packing films on the ground...whoops!

View attachment 21652

Going to immediately check mine right now !!

(all good )

 

[Glen]

I'm super annoyed whenever I see that protective plastic film left on things in people's homes, when they're not looking I'll peel it off! lol
So when I unboxed my Mavic it only took me seconds to have all them plastics taken off everything.

Also... isn't it a no no to fly much with the camera dome on? Doesn't it affect cooling? It's not really going to do much protecting in a crash anyway right? As we can see from the results of this crash.

 

[Maldor]

Oh yikes! My drone got pushed into a tree and it was minor cosmetic damage. Glad to know that the mavic can stand up to plenty more punishment.

I'm super annoyed whenever I see that protective plastic film left on things in people's homes, when they're not looking I'll peel it off! lol
So when I unboxed my Mavic it only took me seconds to have all them plastics taken off everything.

Also... isn't it a no no to fly much with the camera dome on? Doesn't it affect cooling? It's not really going to do much protecting in a crash anyway right? As we can see from the results of this crash.

I think that is personal preference, I have not had any problems with it on (the cover I mean, not the plastic (Serves a temporary purpose of protecting things till I get better protection for my things))

 

[sar104]

Oh yikes! My drone got pushed into a tree and it was minor cosmetic damage. Glad to know that the mavic can stand up to plenty more punishment.

I think that is personal preference, I have not had any problems with it on (the cover I mean, not the plastic (Serves a temporary purpose of protecting things till I get better protection for my things))

Aside from possible cooling issues, the cover seriously degrades the camera images.

 

[Oingo Boingo]

There are a lot of things that could cause this. First mistake was flying through cracks in rocks. Rocks can carry massive amounts iorn. It can cause serious signal problems on the mavic. It's basically like turning off your control. As u don't know what the iron levels are in Rock around you, flying through cracks in them is like rolling the dice

 

[Sparky1]

RECOVERED! It was a day-long odyssey to recover my drone starting with a 10 mile 4WD (low-range) drive to a good launch point, a 2 mile distant reconnaissance with my new drone, a "friendly" ride with the mining company security vehicle to the crash site and a pretty sketchy 30 minute hike off the side of a cliff.

I agree with what the above posters said. Plus, I found (believe it or not!) one of the forward sensor packing films on the ground...whoops! So, it was apparently the cause of the Forward Sensor Error. It hit hard enough on the mountain edge to eject the battery (never found), shatter the camera bubble and camera lens and bang up the front pretty good. Attached are the salvage photos.

View attachment 21651 View attachment 21652 View attachment 21653

So I noticed you also have that plastic film piece with the yellow tab on it on top of the gimbal. I also have that. It was not really coming off and I didn't want to damage the camera gimbal. Does anyone know if that matters if that's on there still?

 

[Robbyg]

So I noticed you also have that plastic film piece with the yellow tab on it on top of the gimbal. I also have that. It was not really coming off and I didn't want to damage the camera gimbal. Does anyone know if that matters if that's on there still?

Do Not Remove It!
Its there to allow the gimbal to smoothly move by the other metal parts. If you remove it you will get scratches on the curved back.

Rob

 

[Robbyg]

RECOVERED! It was a day-long odyssey to recover my drone starting with a 10 mile 4WD (low-range) drive to a good launch point, a 2 mile distant reconnaissance with my new drone, a "friendly" ride with the mining company security vehicle to the crash site and a pretty sketchy 30 minute hike off the side of a cliff.

I agree with what the above posters said. Plus, I found (believe it or not!) one of the forward sensor packing films on the ground...whoops! So, it was apparently the cause of the Forward Sensor Error. It hit hard enough on the mountain edge to eject the battery (never found), shatter the camera bubble and camera lens and bang up the front pretty good. Attached are the salvage photos.

View attachment 21651 View attachment 21652 View attachment 21653

To bad you did not have DJI refresh, this would have been a perfect case for it.


Rob

 

[Sparky1]

Do Not Remove It!
Its there to allow the gimbal to smoothly move by the other metal parts. If you remove it you will get scratches in the curved back.

Rob

Hey thanks Rob! Glad I didn't remove it! I totally thought it was just a film you remove. Good to know! Cheers

 

[Lapeer20m]

did you put a battery in it? I"m curious to know if it'll fire up.

 

[FlyGuy8675309]

Man that thing got trashed!
It's funny, I beat the crap out of my toy drones (ones under $50) and I can't destroy them. Worst thing that's happened is a bent prop. My $35 Mavic knockoff went through some tree branches and just kept going (after taking out some leaves).

 

[kylerf150]

Do Not Remove It!
Its there to allow the gimbal to smoothly move by the other metal parts. If you remove it you will get scratches in the curved back.

Rob

Whoops I removed mine