I'm new here, my drone left me on the mountain.

[GRH]

I had a fly away last week on my second flight on top of a mountain with a Mavic 3 Pro. The drone was in cruise control and the controller screen went blank with no warning. The signal transmission bar were still all white at the time, no orange bars, no video distortion, no warning except the final drone disconnected message. RTH failed. The drone went down on a steep hillside in deep power snow. "Locate My Drone" worked fine. I hitch a ride with a passing snowmobile but failed in a rescue attempt on snowshoes. The snow was too deep and the terrain too steep. The area has had 300 inches of snow this season. I could never get closer than 200 feet to the drone. Linked is the fly log file and a low rez cache video file of the flight that I found on my RC Pro controller.

flight log file etc.

 

[MA2 317]

Hello from the Crossroads of America GRH.

Sorry about your loss.

Welcome to the Forum.

 

[GFields]

Greetings from Birmingham Alabama USA, welcome to the forum! We look forward to hearing from you!
Some great folks might be able to help you. I downloaded your flight log and uploaded it to see what can be found. Here's the link, DJI Flight Log Viewer - PhantomHelp.com

You were over 4,500 feet away from the home point when you lost the signal. That's really all I can see.

 

[old man mavic]

welcome to the forum ,sorry that your drone has been lost ,

 

[Meta4]

I had a fly away last week on my second flight on top of a mountain with a Mavic 3 Pro. The drone was in cruise control and the controller screen went blank with no warning.

To say that your drone flew away, suggests that it mysteriously flew off without your control.
Your drone didn't fly away.
You set it to cruise control and left it in cruise control.
The drone followed the track it was on, which is what cruise control does.

Until about about 1:45, the done was in level flight, but after that it started to lose height slowly, still continuing on the path it was on when you engaged cruise control.
At 2:57.2, the descent rate increased, but you left the drone to power on in cruise control.
At 3:12.1 with the drone 4500 feet away, signal was lost when it was blocked by a large hill between you and the drone.

The reason for the descent isn't shown in the data.
Why didn't you cancel cruise control and resume control?
If there was no problem with the drone's systems, that would have stopped the descent.

 

[GRH]

To say that your drone flew away, suggests that it mysteriously flew off without your control.
Your drone didn't fly away.
You set it to cruise control and left it in cruise control.
The drone followed the track it was on, which is what cruise control does.

Until about about 1:45, the done was in level flight, but after that it started to lose height slowly, still continuing on the path it was on when you engaged cruise control.
At 2:57.2, the descent rate increased, but you left the drone to power on in cruise control.
At 3:12.1 with the drone 4500 feet away, signal was lost when it was blocked by a large hill between you and the drone.

The reason for the descent isn't shown in the data.
Why didn't you cancel cruise control and resume control?
If there was no problem with the drone's systems, that would have stopped the descent.

Thanks for your comments. There is still more than what it seems on the surface.

As soon I noticed that the drone was dropping I pressed forward on the left stick to raise altitude but the drone did not respond. By the time I disengaged the cruise control the connection to the drone was already lost. I don't know if you are familiar with the Mavic 3 Pro but it responds to directional control and speed changes even when in cruise control. Often raising the altitude by just a small amount will restore the connection. Also when the transmission signal becomes weak you will be warned ahead of time by the signal bars changing color. This never happened. The last fail safe which has never failed me is the automatic RTH (return to home) with happens when the signal is lost. This drone never returned to home. I have a friend who ran the flight log file through a flight analysis program called "FRAP" and he pointed out to me that the drone was loosing altitude but thinking it was gaining altitude.

I had considered that maybe the props had become iced up. That had happened on a previous trip but the weather conditions were very different. The day the props got iced up it was foggy and the temps were in the teens. The day of the doomed flight it was near 30 degrees with sunshine. I had just finished a 30 minute flight and changed to a fresh battery when this happened. This drone had never been dropped, never had a crash, never even had a nick in a propeller. New propellers had been put on it the week before.

Below is my first flight video I did a few months after I got the drone. The drone is on cruise control for the whole video. Some of the times when the drone suddenly goes up in the air is when it showed the signal strength was weakening so I just gained altitude to restore it. I'm still perplexed by the experience. Maybe when/if I recover the drone in July DJI will be able to tell me more from the onboard data files (black box?).

You are welcome to reply with any additional thoughts.

Entire flight on cruise control.

 

[LoudThunder]

I had a fly away last week

Welcome from the Hampton Roads area of Virginia, USA. We have a Member's Map in the Upper Right of the Title Bar. Click on "Members" and then Click on "Member's Map…" Check it out and you might find some new flying friends.

Member Map

mavicpilots.com

I am also sorry to hear of your loss. If you are ever able to recover it after the snow melt is will probably be unrepairable…

 

[Meta4]

Thanks for your comments. There is still more than what it seems on the surface.

As soon I noticed that the drone was dropping I pressed forward on the left stick to raise altitude but the drone did not respond. By the time I disengaged the cruise control the connection to the drone was already lost.

I don't know if you are familiar with the Mavic 3 Pro but it responds to directional control and speed changes even when in cruise control.

The manual doesn't say whether joystick input during cruise control works and it's a feature I haven't used.
Perhaps someone who uses cruise control can tell how it works for them.

Earlier in the flight you used both throttle and rudder at 1:51 and 2:20, but this made no difference to the drone's heading or height.

Often raising the altitude by just a small amount will restore the connection. Also when the transmission signal becomes weak you will be warned ahead of time by the signal bars changing color. This never happened.

You had a large hill between you and the drone.
The drone was descending quite fast towards the end of the data.
Signal was lost when the line of sight between the controller and drone was lost, with the drone descending behind the hill.
You would never get any warning in that situation.

Unfortunately there is no data to show what happened after signal was lost and help understand why the drone did not RTH on losing signal.
I cannot see what caused the descent to start, but leaving the drone in cruise control, contributed to the loss by continuing the descent.

The rate of descent was a steady 6 metres/sec.
This appears to be controlled, rather than an uncontrolled descent due to lack of thrust, such as what might occur due to prop icing.

 

[LoudThunder]

You were over 4,500 feet away from the home point when you lost the signal.

This is the map as it is tilted viewing North. I believe you lost signal due to the extreme range and the hill with Howell Canyon Road on it prevented line of sight and thus the loss of signal. Did you have your drone set up to Return to Home of perhaps Hover with loss of signal? The line only shows the direction of flight not the flight altitude.

 

[Meta4]

Did you have your drone set up to Return to Home of perhaps Hover with loss of signal?

Failsafe action was on the default setting ... RTH

 

[LoudThunder]

Failsafe action was on the default setting ... RTH

I fly a Mini 2 and it does not have the capabilities of the more sophisticated drones, so I go for the more basic possibilities, like: did you turn it on? How were the wind conditions, is it possible that as the drone flew over the hill, it lost signal and then it was hit by a sudden downdraft that made recovery impossible? Like I wrote, I go for the basic possibilities as in Occam's razor (where you must accept the simplest possible theoretical explanation for existing data…).

 

[MARK (LI)]

That Dronescape video is beautiful....I hope getting that video compensates your emotions for losing the drone...I always regret hearing about someone's bad fortune; losing his drone

 

[GRH]

This is the map as it is tilted viewing North. I believe you lost signal due to the extreme range and the hill with Howell Canyon Road on it prevented line of sight and thus the loss of signal. Did you have your drone set up to Return to Home of perhaps Hover with loss of signal? The line only shows the direction of flight not the flight altitude.

View attachment 173014

Yes, it was set to RTH. That is what is so perplexing. It has always worked before. What was different this time!

 

[LoudThunder]

What was different this time!

Perhaps it was just a catastrophic failure: a short, a bad solder joint, a failed component; I guess we will never know because even if it it ultimately recovered after the snow melt, it will probably be so badly damages that DJI will not even bother to check…

I had a drone replaced under the Care Refresh and it was a new one. But within a couple of days it gave communication error messages and DJI replaced it under warranty, so even NEW Drones can go bad…

 

[Kendallfordguy]

Welcome from Wisconsin! Sorry for the loss of your drone.

 

[PakNheat380]

You came to the best place for answers. Meta4, LoudThunder & slup along with a few others are experts in this drone community. If there’s an explanation as to what happened, one of these guys will find it. Welcome to the forum from NW Montana.

 

[GRH]

Perhaps it was just a catastrophic failure: a short, a bad solder joint, a failed component; I guess we will never know because even if it it ultimately recovered after the snow melt, it will probably be so badly damages that DJI will not even bother to check…

I had a drone replaced under the Care Refresh and it was a new one. But within a couple of days it gave communication error messages and DJI replaced it under warranty, so even NEW Drones can go bad…

Thanks for you encouragement. I have Care Refresh and the replacement drone arrived yesterday. 5 days from the report date is pretty fast response time. I connected it to the controller last night but am a little nervous about sending it up in the air for some reason. My testing ground is a forty acre field behind my house so later today is first launch time.

 

[GRH]

You came to the best place for answers. Meta4, LoudThunder & slup along with a few others are experts in this drone community. If there’s an explanation as to what happened, one of these guys will find it. Welcome to the forum from NW Montana.

Thank you.

 

[GRH]

That Dronescape video is beautiful....I hope getting that video compensates your emotions for losing the drone...I always regret hearing about someone's bad fortune; losing his drone

Yes, losing a drone really feels like losing friend.

 

[GRH]

Yes, it was set to RTH. That is what is so perplexing. It has always worked before. What was different this time!

This is a video I did for someone else to explain how RTH works. The video is from a cached file on the controller, not from the drone itself. That way you can see the video distortion when the transmission signal becomes iffy. This footage is from earlier but in the exact same area. The drone was in cruise control at the time:
RTH Example