2 lost Mavic pros

[boblui]

any ideas on what happens? Does drone go straight down? Would it veer left or right? Could it continue flying till battery ran out?

In the second flight, the downlink signal ( ie, video feed and telemetry data ) started breaking up when the drone was 1900 ft away from the home point indicating that there was either interference or there were some problem with the radio on the controller / drone side.



Anyway, RTH has already started before the black out and there was a mild tail wind so the drone should have returned to the home point automatically after 1.6 minutes unless something happened on the way.

 

[Meta4]

Everything fine till about 4 feet off ground- drone just dropped- area was soft so no damage done but it was a hard fall
I thought the elevation was just off and continued to fly
Thinking back maybe that happened again but much higher

I'm not sure about the landing you mentioned but the elevation makes no difference to a landing.
It doesn't matter where it's landed and it will descend until it can't descend any more.
Even if it did happen in these flights (it didn't) that wouldn't explain losing signal (which would have triggered RTH anyway).

In any event in your opinion both drones should be very close to their last position?
You think they both went straight down?

In the event of a fall-from-the=sky incident, they would be close to the last location received + some additional distance for the forward motion of the drone since both were still flying, +/- a little for any wind effect.
GPS locations for the last locations received were
33.21062 -80.88009 - drone would be close to here
33.18115 -80.90733 - drone is probably a little SW of here if it fell

Do you know of any way they could have flown off on their own without sending data back to controller?
The old bat out of hell flight to freedom?

No
People love to talk about "flyaways" but it just doesn't happen, and if it did there would be a data trail.

 

[boblui]

In any event in your opinion both drones should be very close to their last position?
You think they both went straight down?
Do you know of any way they could have flown off on their own without sending data back to controller?

The drone was doing RTH so it should have flown a straight line towards the home point. If it dropped out of the sky for any reasons, it should not be far away from the flight path. Unfortunately part of the flight path was over some trees so you may want to check the trees as well. The red dot is the last recorded position. Suggest to search along the line joining that point and the home point.

 

[radio5991]

From my long ago school days I estimated about 4 to 5 seconds to fall
At 20 mph horizontal speed- 120 to 150 feet toward home point from last position?

 

[boblui]

From my long ago school days I estimated about 4 to 5 seconds to fall
At 20 mph horizontal speed- 120 to 150 feet toward home point from last position?

The craft did not necessarily drop out of the sky at the last recorded position. The lost of connection at that point could be just due to signals being blocked. After that the craft should continue to fly towards the home point until something happened.

 

[SmilingOgre]

Only posting because I want to learn more about this. Have not had any of these problems. Did loose communication once with the drone while under a bridge but by waiting a bit it regained enough signal for me to get it back into the open and got the drone back home. Would also love to learn how to analyze flight data to the extent I see posted here. Have used flight logs and have found them to be very accurate per direction of flight, camera facing and tracing of gps coordinates.

 

[maelstrom]

Did loose communication once with the drone while under a bridge but by waiting a bit it regained enough signal for me to get it back into the open and got the drone back home.

Flying under things like bridges is always dangerous if your setting for loss of signal is to RTH. The drone would climb up to the preset RTH height and probably hit the bridge. You were lucky to get the signal back in time to prevent it happening.

 

[SmilingOgre]

Flying under things like bridges is always dangerous if your setting for loss of signal is to RTH. The drone would climb up to the preset RTH height and probably hit the bridge. You were lucky to get the signal back in time to prevent it happening.

I get that for sure. Really freaked me out. I was waiting for it to bounce of the bottom of the bridge. Lucky, the signal was "flickering" in and out and I was able to get enough control to get it out from under the bridge. I learn something from every flight no doubt. Flight distances and video signal is also something I am finding varies greatly per obstacles between the controller and the drone. Wooded areas and I'm lucky to get a 1/4 of a mile. Over a lake I've never found a limit. For now I'm going to keep my flights to line of sight. The thing is too expensive to take many chances with.

 

[radio5991]

The drone was doing RTH so it should have flown a straight line towards the home point. If it dropped out of the sky for any reasons, it should not be far away from the flight path. Unfortunately part of the flight path was over some trees so you may want to check the trees as well. The red dot is the last recorded position. Suggest to search along the line joining that point and the home point.

View attachment 113027

As I understand and have seen, RTH will occur at a preset altitude OR higher if drone was higher when RTH was activated
It lost commication at 350 feet and RTH was set for 164 feet- both greater than height of trees by 30-40 feet
However, I will look around trees and along the RTH path
Leaves beginning to fall off cotton plants so that will help-I can see the rattlesnake just before he bites LOL
Thanks

 

[SpitFire]

I have been flying Mavic Pro for four years now, although these pros are designed for long distance, but have never in four years flown it out of VLOS. I have strobes on it, find my drone activated in case it goes down. Also a addition locating device, if find my drone fails. The Occusinc transmission is good, working very well within VLOS. From what I understand the Mavic 2 has a much better and improved Occusinc transmission system for more reliable long distance flights.
Do some research about the new Mavic 2, I have two Mavic Pros, and am perfectly happy with both of them. Also, I never push the limits on either of them. Sorry, about your drone loss. I know how I would feel, if I lost one.

 

[radio5991]

Do I understand that you have a secondary tracking device installed on your drones to locate them if they go down?
Details?

 

[randyatkinson]

I have lost 2 drones in a little over 2 months and am looking for some advice to maybe find whats left Similar circumstances: 1st was a mavic pro with about 250 flights logged when it just lost communication with controller It was 3500 feet away at 320 feet high with 70% battery left It was a wooded area but I had coordinates of last position Looked several hours and have returned several times with no luck I bought a new Platinum but did not even unpack the new controller- just used the other with the Ipad attached Used it for 25+ flights when same thing happened- sudden loss of communication Drone was RTH 2500 feet away at 360 feet up over a cotton field Not quite in sight but I was looking at screen when it lost Again good location but after hours walking in waist high cotton- no drone Obviously I suspect controller is just shutting down drone and will never use this controller again Any ideas on what happens? Does drone go straight down? Would it veer left or right? Could it continue flying till battery ran out? Appreciate your thoughts

About a month ago I lost a Mavic Pro when I was using it to video a ravine in Arizona. I lost signal to the controller and also visual to the Mavic Goggles I was using. I had the lost signal situation set to have the drone go to hover. When the battery got to 25% the drone started RTH. Since I was flying in an area where the hills were of an elevation greater than 400 feet the drone ran into an obstacle of a hillside. When the battery got to a critically low level the drone self landed. I heard this through the controller but could not understand why visual signal and control wasn't reestablished. Unfortunately the flight log was not being recorded and the map screen apparently wasn't working either. Probably from an exceeded cache memory.
I think it would be really great if DJI would design their drones to RTH along a reverse of the their flight path rather than a direct flight path back to the home point where it can run into an obstacle and self land as mine did.
I recently bought a Mavic 2 and am going to use it to search for the drone I lost but I will start from a home point with a better line of sight with no obstacles. I'm also using a tablet with a high memory capacity. I also just now bought the Marco Polo Drone Recovery System which I intend to use. Hopefully I wont lose my new drone and if I do I should be readably able to find it.

 

[Marko9219]

About a month ago I lost a Mavic Pro when I was using it to video a ravine in Arizona. I lost signal to the controller and also visual to the Mavic Goggles I was using. I had the lost signal situation set to have the drone go to hover. When the battery got to 25% the drone started RTH. Since I was flying in an area where the hills were of an elevation greater than 400 feet the drone ran into an obstacle of a hillside. When the battery got to a critically low level the drone self landed. I heard this through the controller but could not understand why visual signal and control wasn't reestablished. Unfortunately the flight log was not being recorded and the map screen apparently wasn't working either. Probably from an exceeded cache memory.
I think it would be really great if DJI would design their drones to RTH along a reverse of the their flight path rather than a direct flight path back to the home point where it can run into an obstacle and self land as mine did.
I recently bought a Mavic 2 and am going to use it to search for the drone I lost but I will start from a home point with a better line of sight with no obstacles. I'm also using a tablet with a high memory capacity. I also just now bought the Marco Polo Drone Recovery System which I intend to use. Hopefully I wont lose my new drone and if I do I should be readably able to find it.

I've never understood using the "set to hover" option during LOS. Why on Earth would I want my drone to park in one place waiting for a battery depletion to force a landing where it is. I want that baby on its way back home! Early in my Mavic Pro days, I flew the Mavic out about a mile and a half, maybe two miles away. I shut the controller off and threw it on the seat of my car. Then waited. Pretty soon, here it came back and landed right in front of me like it was supposed to. Had it been set to hover on LOS.. It would've been lost forever in the Great Salt Lake of Utah, USA.

 

[JAW]

think it would be really great if DJI would design their drones to RTH along a reverse of the their flight path rather than a direct flight path back to the home point where it can run into an obstacle and self land as mine did.

That’s exactly what it does for 60 seconds after loss of signal. If the signal is not regained, then it flies in a straight line to the home point.

 

[Jerdog]

I just had this happen to me also. Be careful to inspect each battery you own. Check to make sure it is not bulging on the bottom. The batteries must be completely flat on the bottom. There are many pilots having the battery disconnect during flight. I was flying a battery that had an ever so small bulge. It required a little extra force to get it to latch when I put it in. My drone fell from the sky. When I retrieved my drone the battery had popped out and the drone fell pretty hard. I picked up the battery and it was hugely bulged and very warm. The discharge of the flight caused it to bulge even further and it pushed out of my M2. Having checked my other batteries, I had one more that was bulging. I have disposed of both of them. Hard lesson learned. It broke my Hasselblad camera and one of the motor arms. Both batteries were almost two years old and had been cycled about 50 times each.

 

[PTBperegrine]

What else could it be but a bad controller?

Battery swelling-are you still using batteries purchased with your original drone?

 

[DJI DelBoy]

The fact that nothing appears out of order leads me to suspect that an external factor might be at work. Possibly a bird attack that has caused your drones to lose control and crash? Any birds nesting in the area where your drones were lost or birds of prey activity?

 

[radio5991]

UPDATE I went today with a good handheld Garmin and marked the last known position with a tall flag
I started a back and forth grid search in tall cotton taking about 4 feet each pass.After about an hour I found drone 150 feet South of last known position
I had anticipated it to be more southwest. Battery case cracked, camera hanging by wires, one prop broken, gimbal clear cover off but I found it about 3 feet from drone. Arms appear intact along with legs.Micro SD ok. LOL
To complicate things we had over 5 inches of rain from remnants of Sally
Sent flight logs to DJI to see if they can help
Warranty?

 

[radio5991]

The fact that nothing appears out of order leads me to suspect that an external factor might be at work. Possibly a bird attack that has caused your drones to lose control and crash? Any birds nesting in the area where your drones were lost or birds of prey activity?

I have seen some hawks take an interest in drones but usually not early in morning.I would not rule that out as big hawks don't play nice.
Nesting season is over here
Thanks

 

[ajkm]

At 3,500ft, very much BVLOS, it’s hardly surprising that a pilot has no idea what happened to his aircraft.