Help... lost my P3... what now?

[Meta4]

Thanks, I am see that as well. I know I was trying to bring it back, but it kept disconnecting. If the uplink was also lost would it also show as no movement in the sticks correct?

There is no recording of stick input when downlink or control signal is lost.

 

[RodPad]

Is there going to be a search?
Or are we assuming its in the water?

Rod

 

[sar104]

Thanks, I am see that as well. I know I was trying to bring it back, but it kept disconnecting. If the uplink was also lost would it also show as no movement in the sticks correct?

The stick inputs recorded in the device file are the stick state on the RC. It doesn't mean that the aircraft is receiving them, and in fact the device can't know whether it is or not if the downlink is lost. If you look at the period from 110 - 120 seconds it is apparent, from the distance before and after, that while the downlink has gone the aircraft is still responding to your full back elevator command.

 

[sar104]

There is no recording of stick input when downlink or control signal is lost.

I'm not sure that can be correct. See the graph I posted above where the downlink was lost from 110 to 120 seconds but the stick inputs were recorded.

 

[sar104]

There is no recording of stick input when downlink or control signal is lost.

On second thoughts maybe that is correct - during all the listed periods of lost downlink there are no changes in the recorded stick inputs, which is unlikely, so perhaps it just keeps the same value until downlink is restored.

 

[Meta4]

I'm not sure that can be correct. See the graph I posted above where the downlink was lost from 110 to 120 seconds but the stick inputs were recorded.

Put it this way ..... No data at all shows in the CSV for periods where the downlink is lost.
But unless the control signal is also lost, control inputs will be received by the Phantom - just not recorded.

 

[sar104]

Put it this way ..... No data at all shows in the CSV for periods where the downlink is lost.
But unless the control signal is also lost, control inputs will be received by the Phantom - just not recorded.

Yes - you are correct. I was overlooking the obvious - that my analysis software is interpolating the missing points. It's clear when plotting markers and lines.

 

[Rlturner524]

Is there going to be a search?
Or are we assuming its in the water?

Rod

I really appreciate the detailed analysis and your guys help! Sorry but I don't think I fully understand, does this mean the drone was receiving my commands the whole time?

You can see when I first started sensing trouble 1:12 I was trying to turn the drone around and at 1:14 it stopped responding until 1:32. RTH should have kicked in but it didn't? At 1:39 it started responding again and I tried pulling it backward but lost contact again around 1:49 and I tried again around 2:07, 2:19 and 2:32 but lost connection at 2:36 to 2:49... again RTH should have kicked in? 3:35 was the last time I really tried to bring it back but it remained unresponsive until 6:03. Not sure why it shows full stick back at 6:03 because I stopped stick movement and jumped in the car hoping to catch it hovering.

I've started a review with DJI because I still think RTH should have kicked in multiple times but since I don't fully understand the data as accurately as you guys do, do I have a potential claim on this? Obviously I know now I was fighting wind and multiple disconnects, but at least once I think RTH would have kicked in.

 

[Thermographer]

OP,

Whether RTH kicked in or not the drone could not and would not be able to over come the wind. As stated before if RTH kicked in it would not descend to your RTH altitude of 90 (I believe you stated it was 90) it would remain at its current altitude of 600+. There for unable to fight and win against the wind unless you commanded it to descend.

 

[epicdoom]

maybe you setting the height as it was taking off messed up RTH. did you get the message that the home point was set before take off? is that something that can be checked in the logs?

 

[Rlturner524]

Looking at the weather records the sustained wind was 11mph, which RTH would have overcome but the gusts occurred twice, unfortunately at the critical times I disconnected. I would think with the battery level I would have seen progress back towards me and the controller if RTH kicked in but obviously did not. I really think I lost the drone the moment I was already turning back to the south at 1:12 and it disconnected. After that it is was brief connections and futile attempts to turn it around. It was also well before the gusts of wind.

I am really curious if RTH settings can be determined from the records. I think my position with DJI will be that because the RTH never enabled after 1:12 I lost the critical seconds / distance to avoid the situation I had already started to do and exposed the drone to those major gusts. I'm not totally clear if the data helps me, but that is definitely my memory of my experience of what happened. Do the data logs blatantly refute that in anyone's opinion?

 

[LarBear360]

maybe you setting the height as it was taking off messed up RTH. did you get the message that the home point was set before take off? is that something that can be checked in the logs?

Too High + Too Far = Too Bad. Regardless of RTH settings, I don't think he had a chance.

 

[Rlturner524]

Looking at the weather records the sustained wind was 11mph, which RTH would have overcome but the gusts occurred twice, unfortunately at the critical times I disconnected. I would think with the battery level I would have seen progress back towards me and the controller if RTH kicked in but obviously did not. I really think I lost the drone the moment I was already turning back to the south at 1:12 and it disconnected. After that it is was brief connections and futile attempts to turn it around. It was also well before the gusts of wind.

I am really curious if RTH settings can be determined from the records. I think my position with DJI will be that because the RTH never enabled after 1:12 I lost the critical seconds / distance to avoid the situation I had already started to do and exposed the drone to those major gusts. I'm not totally clear if the data helps me, but that is definitely my memory of my experience of what happened. Do the data logs blatantly refute that in anyone's opinion?

And yes I ALWAYS make sure the home point is good because I was paranoid of it hitting something on its way down and scenarios like this!

 

[Thermographer]

Looking at the weather records the sustained wind was 11mph, which RTH would have overcome but the gusts occurred twice, unfortunately at the critical times I disconnected. I would think with the battery level I would have seen progress back towards me and the controller if RTH kicked in but obviously did not. I really think I lost the drone the moment I was already turning back to the south at 1:12 and it disconnected. After that it is was brief connections and futile attempts to turn it around. It was also well before the gusts of wind.

I am really curious if RTH settings can be determined from the records. I think my position with DJI will be that because the RTH never enabled after 1:12 I lost the critical seconds / distance to avoid the situation I had already started to do and exposed the drone to those major gusts. I'm not totally clear if the data helps me, but that is definitely my memory of my experience of what happened. Do the data logs blatantly refute that in anyone's opinion?

At what altitude was the sustained wind speed 11mph?

 

[Rlturner524]

At what altitude was the sustained wind speed 11mph?

That's from the weather station less than a 1000' from its last position. I realize it is not the same at 600'. But my experience that night doesn't suggest sustained high winds. That's why I am asking the earlier posters/ experts here if the data clearly shows my phantom was running full out fighting the wind as in RTH kicked in? It appears that every time i lost signal it was drifting east at 5-6 mph. My question is was it fighting to stay in position and just losing?

For the record, I know I'm still very much a novice. I would not go back to DJI if I just flat out did something stupid. I'm just not sure I did. In retrospect obviously now knowing the high winds at upper levels I would not have flown, but Watching the drone and how it didn't react to controls multiple times and then got sucked into the high elevation wind after trying to turn back with no sign RTH ever attempted kicked in as it should have, I think I have some position? Humbly looking for the more experienced here to tell me if that isn't the case.

 

[captainmilehigh]

Suggest you reread post #29 by @Thermographer above. Even if RTH was initiated, at that high altitude with high winds aloft, the bird couldn't make any forward progress toward home due to fighting these winds....blowing it further away from home point.

Eventually Critical Low Battery would kick in, and the bird would begin autoland. Hate to say it, but I see pilot error in this case. Just my 2 cents. Sorry for your loss.

 

[sar104]

Looking at the weather records the sustained wind was 11mph, which RTH would have overcome but the gusts occurred twice, unfortunately at the critical times I disconnected. I would think with the battery level I would have seen progress back towards me and the controller if RTH kicked in but obviously did not. I really think I lost the drone the moment I was already turning back to the south at 1:12 and it disconnected. After that it is was brief connections and futile attempts to turn it around. It was also well before the gusts of wind.

I am really curious if RTH settings can be determined from the records. I think my position with DJI will be that because the RTH never enabled after 1:12 I lost the critical seconds / distance to avoid the situation I had already started to do and exposed the drone to those major gusts. I'm not totally clear if the data helps me, but that is definitely my memory of my experience of what happened. Do the data logs blatantly refute that in anyone's opinion?

You are misunderstanding the weather report. The 12 (11.7) mph wind report was a local ground station. That bears little relationship to the winds aloft at 600 ft, especially in coastal regions. Those 45 mph reports are not gusts, they are wind calculations from a combination of recorded pitch/roll angle and ground speed (time derivative of GPS position data). The AirData alogorithms calculate them during any periods of sustained, constant flight. You can assume from those data that the sustained winds at 600 ft were in excess of 40 mph, and maybe more.

The RTH settings are apparent in the records. At 63 seconds you reset the RTH altitude to 90 m. Any sustained loss of uplink (> 3 s) would have triggered RTH, but that did not happen at least up until your last downlink connection at 368 seconds, since the aircraft was still reporting P-GPS mode. I'm sure that it did go to RTH mode at some point after that, but it was irrelevant at that altitude and wind speed - it had no chance of returning.

The data do not help you. You launched in windy conditions, climbed to 600+ ft and flew downwind where the wind speed and direction made it impossible to bring the aircraft back, probably even in sport mode, and then flew far enough away that you lost downlink and, eventually, uplink. It was clearly pilot error.

 

[Rlturner524]

You are misunderstanding the weather report. The 12 (11.7) mph wind report was a local ground station. That bears little relationship to the winds aloft at 600 ft, especially in coastal regions. Those 45 mph reports are not gusts, they are wind calculations from a combination of recorded pitch/roll angle and ground speed (time derivative of GPS position data). The AirData alogorithms calculate them during any periods of sustained, constant flight. You can assume from those data that the sustained winds at 600 ft were in excess of 40 mph, and maybe more.

The RTH settings are apparent in the records. At 63 seconds you reset the RTH altitude to 90 m. Any sustained loss of uplink (> 3 s) would have triggered RTH, but that did not happen at least up until your last downlink connection at 368 seconds, since the aircraft was still reporting P-GPS mode. I'm sure that it did go to RTH mode at some point after that, but it was irrelevant at that altitude and wind speed - it had no chance of returning.

The data do not help you. You launched in windy conditions, climbed to 600+ ft and flew downwind where the wind speed and direction made it impossible to bring the aircraft back, probably even in sport mode, and then flew far enough away that you lost downlink and, eventually, uplink. It was clearly pilot error.

Appreciate the honest feedback and in retrospect, knowing what I know would never have flown. Clearly not being a pro, certainly impacted final end. That being said I can't get over the behavior I saw with disconnects and what the data says. I lost uplink (>3 sec) @ 1:14 and multiple times up to, not... just at 368 seconds and RTH clearly wasn't initiated because at times I had elevation and directional control multiple times and no feedback suggests it was. There is no way of saying that sustained wind was 40+. That would mean a categorization of a tropical storm was 600' over south jersey while the ground was a calm fall evening.


Can you or anyone see that the drone was full on fighting a wind from the start or confirm RTH was initiated at 1:14 as it should have been?

 

[sar104]

Appreciate the honest feedback and in retrospect, knowing what I know would never have flown. Clearly not being a pro, certainly impacted final end. That being said I can't get over the behavior I saw with disconnects and what the data says. I lost uplink (>3 sec) @ 1:14 and multiple times up to, not... just at 368 seconds and RTH clearly wasn't initiated because at times I had elevation and directional control multiple times and no feedback suggests it was. There is no way of saying that sustained wind was 40+. That would mean a categorization of a tropical storm was 600' over south jersey while the ground was a calm fall evening.


Can you or anyone see that the drone was full on fighting a wind from the start or confirm RTH was initiated at 1:14 as it should have been?

You lost downlink, not necessarily uplink. RTH is initiated by loss of uplink. RTH was not initiated in the logged part of this flight.

You can certainly choose to ignore the wind data, but that simply shows a misunderstanding of how wind speed can vary with height above the ground and an unwillingness to accept the AirData analysis. It is not at all uncommon to see wind speed variations of that kind. I think we have exhausted all possible avenues of assistance in this case. Good luck with DJI - they can be somewhat random in their decisions so it is worth asking them.

 

[Rlturner524]

You lost downlink, not necessarily uplink. RTH is initiated by loss of uplink. RTH was not initiated in the logged part of this flight.

You can certainly choose to ignore the wind data, but that simply shows a misunderstanding of how wind speed can vary with height above the ground and an unwillingness to accept the AirData analysis. It is not at all uncommon to see wind speed variations of that kind. I think we have exhausted all possible avenues of assistance in this case. Good luck with DJI - they can be somewhat random in their decisions so it is worth asking them.

I appreciate the advice and opinion. Honestly, thank you to all who took the time to look at the logs. I am not ignoring or denying wind was a significant role here, But to me its about when it became a factor. I maintained line of sight and I saw it drift after disconnect. Not controller response. Not struggle to come home at 1:14 plus 3 as it should have I just didn't see the redundant safety factors that DJI sells their platform on, kicking in here at all. I will keep all posted