M2Z OccuSync Glitch = Lost Drone

[DC102]

Unfortunately we see flight behavior like this a bit too often in the threads and have now become a bit used to it (jaded) as we accept that some novice and not so novice uneducated drone flyers have not striven to understand the laws and regulations of the airspace. Usually young and entitled types that just think the Mavic is a toy and want to fly into low earth orbit.

Lots of members dont condone this flight behavior and would chastise , but refrain from posting what some would construe as negative sentiments.

I understand how others choose to turn the other cheek even if they know it’s wrong. That is what surprises me. As a professional pilots we should hold all pilots to the minimum standards. Peer accountability, moral courage and professionalism. It’s not negative sentiment. It’s about integrity.

 

[sar104]

I understand how others choose to turn the other cheek even if they know it’s wrong. That is what surprises me. As a professional pilots we should hold all pilots to the minimum standards. Peer accountability, moral courage and professionalism. It’s not negative sentiment. It’s about integrity.

There was plenty of criticism in this thread. But the OP seemed to take it seriously, and I don't think that many subsequent posters felt the need to pile it on further.

 

[GMav380]

At 1:39 in the Video, the OP says he gets out of his car to restore LOS.
Perhaps this is the simple explanation for the lost connection? Operating from inside a car would cause signal attenuation.



The next comment on the video is that, "The control switch has no effect."


... and shortly after, "... I disconnect the phone."


Is it possible that the initial disconnect resulted from being inside a car, and then there was too much switching and and disconnecting to allow the controller time to reconnect to the aircraft?
If this is the reason for the the loss of signal, the aircraft could have been hovering trying to reconnect, but drifting away due to strong winds.
Without continued connection we don't know what the wind became after the signal loss - it may well have been increasing.
With too much switching stopping the reconnection, the aircraft may have just hovered away with the wind.

 

[sar104]

At 1:39 in the Video, the OP says he gets out of his car to restore LOS.
Perhaps this is the simple explanation for the lost connection? Operating from inside a car would cause signal attenuation.

View attachment 67756

The next comment on the video is that, "The control switch has no effect."
View attachment 67757

... and shortly after, "... I disconnect the phone."
View attachment 67758

Is it possible that the initial disconnect resulted from being inside a car, and then there was too much switching and and disconnecting to allow the controller time to reconnect to the aircraft?
If this is the reason for the the loss of signal, the aircraft could have been hovering trying to reconnect, but drifting away due to strong winds.
Without continued connection we don't know what the wind became after the signal loss - it may well have been increasing.
With too much switching stopping the reconnection, the aircraft may have just hovered away with the wind.

In general that's a possibility. In this case, however, there was zero data loss prior to the disconnect. That never happens if the disconnect is due to poor signal with LOS.

 

[GMav380]

In general that's a possibility. In this case, however, there was zero data loss prior to the disconnect. That never happens if the disconnect is due to poor signal with LOS.

Fair point - it is still showing 3 bars on the link signal just prior to disconnect.
Far more likely that the problem is a consequence of being at 1500' in strong wind (and who knows what level of turbulence) and then rapidly going full throttle and also switching to Manual mode.
It would be hard to predict what vertical and horizontal velocities were generated in Manual mode after the link went down.
I feel sorry for that poor little Mavic being abused like that.

 

[sar104]

Fair point - it is still showing 3 bars on the link signal just prior to disconnect.
Far more likely that the problem is a consequence of being at 1500' in strong wind (and who knows what level of turbulence) and then rapidly going full throttle and also switching to Manual mode.
It would be hard to predict what vertical and horizontal velocities were generated in Manual mode after the link went down.
I feel sorry for that poor little Mavic being abused like that.

I think you are still missing the point - that the link most likely went down due to power loss, at which point the aircraft just fell from the sky.

 

[GMav380]

Are there any other clues in the data prior to signal loss that might indicate the cause of the power loss?
@sar104, you mentioned, "it may have suffered a battery disconnect or an FC crash."
If an FC fails would you still expect the link to stay active?
It concerns me that a M2 could just suddenly go dead like that, so I'm trying to understand this.
I'm trying to interpret the graph at post #18, but I'm not familiar with it. Are these interpretations correct?
From ~346secs, the throttle is pushed to full with elevator neutral and the height increases steadily. At ~348secs the flycState is set to Manual at which point the blue , red and green lines move. Are the blue, red and green lines showing: a yaw to the right, a pitch up and some roll? And are the hashed red and green lines showing an increasing negative speed in x and y?
I appreciate any feedback.

 

[sar104]

Are there any other clues in the data prior to signal loss that might indicate the cause of the power loss?
@sar104, you mentioned, "it may have suffered a battery disconnect or an FC crash."
If an FC fails would you still expect the link to stay active?
It concerns me that a M2 could just suddenly go dead like that, so I'm trying to understand this.
I'm trying to interpret the graph at post #18, but I'm not familiar with it. Are these interpretations correct?
From ~346secs, the throttle is pushed to full with elevator neutral and the height increases steadily. At ~348secs the flycState is set to Manual at which point the blue , red and green lines move. Are the blue, red and green lines showing: a yaw to the right, a pitch up and some roll? And are the hashed red and green lines showing an increasing negative speed in x and y?
I appreciate any feedback.

No prior indications of power loss that I can see, but then there rarely are. The comms link goes down if the FC crashes.

Your interpretation of the data plotted is correct - here's a closer look at the end of the flight:

 

[TheFoxSaysRingADingDing]

Question, does the props turn off when when the MP is at 90 degrees? I've seen videos where people hand catch a MA and turn it upside down, and it stops the props. If I'm reading the data right, it looks like the pitch was at about 38 degrees and then started to go down fast?

 

[sar104]

Question, does the props turn off when when the MP is at 90 degrees? I've seen videos where people hand catch a MA and turn it upside down, and it stops the props. If I'm reading the data right, it looks like the pitch was at about 38 degrees and then started to go down fast?

They don't turn off in the air, for obvious reasons.

 

[TheFoxSaysRingADingDing]

They don't turn off in the air, for obvious reasons.

Rolls, flips, and full acro mode with a mavic pro.-nolimitdronez.com

No disrespect sar104, you're a lot smarter than I am at this! I know this webpage above is for an orginal MP, but it mentions the IMU getting confused? And it might shut down if turned over?

I'm also curious to know your thoughts since I'm a pretty big physics nerd too and would like to know

 

[sar104]

Rolls, flips, and full acro mode with a mavic pro.-nolimitdronez.com

No disrespect sar104, you're a lot smarter than I am at this! I know this webpage above is for an orginal MP, but it mentions the IMU getting confused? And it might shut down if turned over?

I'm also curious to know your thoughts since I'm a pretty big physics nerd too and would like to know

There have been multiple logs posted, mostly for prop loss or motor failure events, recording Mavics of all flavors tumbling and inverting as they fell. In none of those cases did the motors shut down, even when fully inverted. There is no uncertainty in that observation. And clearly you wouldn't want motor shut down in the air - if the aircraft hits something, whether a bird, tall tree or whatever, it is likely to recover provided that the motors remain running. My conclusion is that shutdown on tilt/inversion only happens if the OSD.groundOrSky flag is set to Ground, i.e. the aircraft has detected that it is no longer flying (or has not taken off).

 

[TheFoxSaysRingADingDing]

There have been multiple logs posted, mostly for prop loss or motor failure events, recording Mavics of all flavors tumbling and inverting as they fell. In none of those cases did the motors shut down, even when fully inverted. There is no uncertainty in that observation. And clearly you wouldn't want motor shut down in the air - if the aircraft hits something, whether a bird, tall tree or whatever, it is likely to recover provided that the motors remain running. My conclusion is that shutdown on tilt/inversion only happens if the OSD.groundOrSky flag is set to Ground, i.e. the aircraft has detected that it is no longer flying (or has not taken off).

Good points sir!

 

[Talmon Murphy]

First things first, I completely deserve the scornful comments and can assure you I feel like quite an idiot here. "One more high flight for the logs, then that's it!"
I didn't anticipate losing control of course, but now I've seen firsthand how hard **** can hit the fan if you do. Not that I am in a position to defend myself, but I did check FlightRadar to make extra sure I was out of the way of any aircraft... Just had to throw that out there. Stupid, stupid extreme-risk low-reward flying - that has effectively lost all of its appeal anyway after this incident! Karma for sure.

Back to the incident, there's a few things to clear up.
The first few comments about wind preventing an RTH don't apply here. The signal-loss action was set to hover. I do this because I often run out-of-range Litchi missions that will RTH early as it is on the fringe of connection. I have briefly lost connection countless times in this mode and have never had an issue restoring it.

It certainly is a bizarre incident, and yes - it was in the mode I will never EVER use again - full manual. With all motor control relying on the pilot, I also can only guess as to what happens when it loses connection.
Many drones that operate normally in this mode will "freeze" on the last command received and zoom out of control. If this is the case then the drone could be a mile away.
If you look at the aircraft's data right before it loses connection, it is actually tilted slightly backwards and could have actually ended up west!

This mode was how I was able to achieve such high speeds but this is the second malfunction that has led to a catastrophic failure and I learned the hard way the aircraft is simply NOT built for it.
Don't put your Mavic in this mode folks.

With a laughable degree of irony and humility I appreciate your help, @sar104 . I just went out to the area for kicks but it is too dark to search and would feel sketchy walking around. If it makes any significant difference, I can say with high certainty (using pitch/roll profiles while in manual) that the wind at that exact time was headed at about 70 degrees. (Slightly north as well)

I'll start the search again tomorrow but honestly I should probably just chalk this one up to a hard lesson learned and stick to the cheapo drones on Amazon.

I’ve bought a Tie to stick to my Mavic 2 Zom onhelp find it in the dark, etc. sorry you lost your drone! [emoji22]That should have said “Tile”.