2 lost Mavic pros

[Meta4]

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.

You can set RTH height to as much as 1640 feet.
There's no 400 ft limit.

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.

From the manual for the Mavic 2:

When Failsafe RTH is activated, the aircraft starts to retrace its original flight route home. ​

If the remote control signal is re-established within 60 seconds of Failsafe RTH being activated, the aircraft hovers at its present location for 10 seconds and waits for pilot commands. ​

The user may tap in the DJI GO 4 or press the RTH button on the remote controller to cancel Failsafe RTH and retake control. ​

If no pilot command is given, the aircraft flies to the Home Point in a straight line. ​

If the remote control signal is still lost 60 seconds after activating Failsafe RTH, the aircraft stops retracing its original flight route and flies to Home Point in a straight line.​

 

[Meta4]

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?

Evidence of a bird attack would show in the flight data (unless the bird could remove the battery without disturbing the drone).
But in both cases the data just stopped with the drone in stable, smooth flight or hovering.

 

[JAW]

...........gimbal clear cover off but I found it about 3 feet from drone.

You were flying with the gimbal cover on?

 

[Peio64270]

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.

That's why I use to prepare all these difficult flights (in ravines, canyons etc.) in my computer with the help of the Litchi's hub, of VLM and of Google Earth, even if if I don't plan to use the mission and to fly manually.
I particularly verify by using the G-E function named "Viewshed" what must be the altitude of the drone at certain points in order to keep the line of sight to the controller.
Below an example with a flight I realized last year over a pyrenean canyon. I draw a yellow cross at the place I planed to stand, about 10m below waypoint 1 and I asked G-E to color in green the basin viewed by the drone when it will will reach waypoint 11. One can immediately see that I will be located in a green area, i.e. that thre is few risk to lose connection with the drone provided that I respect an altitude of at least 150m above the take off point (by security, I set 160m at waypoint 11) which is 102m RTG.
If I set an altitude of only 110m at this waypoint (42m RTG) G-E Viewshed shows immediately that I will be located into a "black hole", with the line of sight interrupted by the cliff (second image below).
This verification is of a great help for any doubtful location.

 

[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.

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.

Absolutely no way I want my drone to reverse its flight path to do a RTH. I might be low on battery. I want a direct path home. Not a repeat of everywhere its been.

 

[JAW]

Absolutely no way I want my drone to reverse its flight path to do a RTH. I might be low on battery. I want a direct path home. Not a repeat of everywhere its been.

Read the manual, “Low Battery RTH.“

 

[DanMan32]

Absolutely no way I want my drone to reverse its flight path to do a RTH. I might be low on battery. I want a direct path home. Not a repeat of everywhere its been.

That's only for loss of signal. The idea is that it had signal in its path for the last 60 seconds so it's likely it can get the signal back from where it's been.

Not sure if low battery RTH overrides signal loss behavior, but I believe it does.

 

[DanMan32]

The logs on an original Mavic are readable so if you can get it to power on far enough to connect Assistant and get the log, it can be analyzed as to what happened during RTH after signal loss.

I did that once with my P3 when it didn't return in a timely manner after signal loss. The log on the app confirmed signal loss, but the log on the AC showed it was still receiving the RC's signal. It was waiting 4 minutes for me to tell it what to do next until battery got low and it RTHed on low battery.

 

[BossBob]

I've never understood using the "set to hover" option during LOS.

When flying below a tree canopy in woods would be a valid case. The last thing you want on loss of signal is for the drone to do anything other than stay in position until you’ve moved and regained control.

 

[randyatkinson]

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.

I don't think you read my posting correctly:

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.

 

[randyatkinson]

You can set RTH height to as much as 1640 feet.
There's no 400 ft limit.

From the manual for the Mavic 2:

When Failsafe RTH is activated, the aircraft starts to retrace its original flight route home. ​

If the remote control signal is re-established within 60 seconds of Failsafe RTH being activated, the aircraft hovers at its present location for 10 seconds and waits for pilot commands. ​

The user may tap in the DJI GO 4 or press the RTH button on the remote controller to cancel Failsafe RTH and retake control. ​

If no pilot command is given, the aircraft flies to the Home Point in a straight line. ​

If the remote control signal is still lost 60 seconds after activating Failsafe RTH, the aircraft stops retracing its original flight route and flies to Home Point in a straight line.​

I was flying an original Mavic Pro. Not a Mavic 2 Pro. I now have a Mavic 2 Pro.

 

[randyatkinson]

I don't think you read my posting correctly:

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 should have stated the RTH for the original Mavic Pro. My new Mavic 2 seems to be doing a RTH along it's flight path because after I loose signal and it's reestablished there is a completely different view in the goggles.

 

[radio5991]

You were flying with the gimbal cover on?

I removed the clear cover every time with 1st drone
When I started with 2nd (platinum) I started leaving cover on to protect camera
I read several opinions on/ off
Only real issue I had was a line caused by glare when flying in certain directions/ sunlight
Your opinion is to remove?

 

[Tufargon]

I removed the clear cover every time with 1st drone
When I started with 2nd (platinum) I started leaving cover on to protect camera
I read several opinions on/ off
Only real issue I had was a line caused by glare when flying in certain directions/ sunlight
Your opinion is to remove?

I'm not sure where you saw those opinions on leaving it on. The gimbal cover must be removed before you turn it on at all times. It's only used to protect the camera/gimbal when the unit is off. When you start the drone the gimbal does a little dance to calibrate. It can easily burn the motors if you don't take it off. Plus you won't be able to move the camera during flight with it on (if the motors haven't burned out already).

 

[randyatkinson]

I was flying an original Mavic Pro. Not a Mavic 2 Pro. I now have a Mavic 2 Pro.

I'll have to learn how to set the maximum flight altitude above the 400 foot elevation from home point.

 

[radio5991]

I'm not sure where you saw those opinions on leaving it on. The gimbal must be removed before you turn it on at all times. It's only used to protect the camera/gimbal when the unit is off. When you start the drone the gimbal does a little dance to calibrate. It can easily burn the motors if you don't take it off. Plus you won't be able to move the camera during flight with it on (if the motors haven't burned out already).

I am not talking about the lock that keeps the gimbal from swinging during transport- that is off
I referring to the clear dome surrounding the entire camera assembly
The camera can move freely with that in place but there is some glare and distortion with it on

 

[Thomas B]

Never happen. Besides what if you over half way through the battery charge..... lost drone.

 

[radio5991]

Evidence of a bird attack would show in the flight data (unless the bird could remove the battery without disturbing the drone).
But in both cases the data just stopped with the drone in stable, smooth flight or hovering.

Question for you: If a prop breaks for any reason in flight(bird, tree, fatigue) what happens?
Does drone try to compensate and continue sending data back? Does drone shut down immediately and fall?
What causes a drone to shut down when it lands? altitude? does it "feel" the surface underneath?
Trying to learn Thanks

 

[Meta4]

Question for you: If a prop breaks for any reason in flight(bird, tree, fatigue) what happens?
Does drone try to compensate and continue sending data back? Does drone shut down immediately and fall?

The flight controller attempts to compensate but the drone needs to have four props working to support it's weight and have control.
If the drone still has power, and signal, the data continues.
If only part of the prop breaks off, the drone might be able to make it back with a bit of extra vibration.
If too much of the prop is missing or the whole prop is gone, the drone tips forward or back depending on where the missing prop came from.
It also rolls to one side and spins because of the unbalanced torque forces and the drone falls from the sky in a fast spiral.
If the drone loses power, you can guess how that goes.

What causes a drone to shut down when it lands? altitude? does it "feel" the surface underneath?

The IMU senses when the drone cannot descend any more, it shuts down or sits idling depending on the model.
Altitude is irrelevant since you can land anywhere, higher or lower than where you launched.

 

[radio5991]

The flight controller attempts to compensate but the drone needs to have four props working to support it's weight and have control.
If the drone still has power, and signal, the data continues.
If only part of the prop breaks off, the drone might be able to make it back with a bit of extra vibration.
If too much of the prop is missing or the whole prop is gone, the drone tips forward or back depending on where the missing prop came from.
It also rolls to one side and spins because of the unbalanced torque forces and the drone falls from the sky in a fast spiral.
If the drone loses power, you can guess how that goes.


The IMU senses when the drone cannot descend any more, it shuts down or sits idling depending on the model.
Altitude is irrelevant since you can land anywhere, higher or lower than where you launched.

Thanks
I did find the platinum very close to where data stopped
Talking to DJI now but they could find nothing from flight log to help(just as you said)
Is there any data stored on drone that might help?