My Pro+ Never Returned Home After Losing Signal? Just disappeared

[flyhelp]

A fellow had an issue, it had to do with signal loss, then RTF. Obstacles between it an home, in this case a tree, stopped the drone as sensors saw the tree. His RTH altitude was below the tree, so it hovered waiting reconnection, that didn't happen, so it emergency landed at 10%, into a treetop.
Unless you recover IT, you don't get the flight logs from it, which can provide answers. But a building could easily have blocked the RTH course, if so, then you would see similar results as I explained.
Best of luck.

Thanks! Yeah, the oddest thing is it was never spotted nor found playing out all these scenarios. Agreed it logistically should have landed there but after hours of search with security involvement, it's surprising it was never found. Fortunately DJI forwarded the logs and said it's sufficient for the data analysis and investigation. Hopefully they will find something out of this. Got to stay positive.

 

[flyhelp]

As pointed out above, it's no surprise that it disconnected - at an altitude AGL of 300 ft it flew behind a building that is 380 ft high:

View attachment 91886

If it continued at 15 mph for 3 seconds (66 ft) it would have been directly behind that building when it attempted to RTH and, since it was already above its RTH height of 98 ft it would not have cleared it. I would expect it to have auto-landed at the end of that building:

View attachment 91888

Yes, I extensively searched that exact spot and was there before battery would have reached the critical point. So before anyone could've have taken it. I looked right in the spot you put the 3D rendition as it was the last recorded capture I had on my screen. While the scenario you show is exactly what should have happened, it is possible something malfunctioned for it's return beyond that point. If it had stayed, I'd had expected the drone to reconnect signal upon my arrival to that location. Just very strange.... it just disappeared like that in a snap. No witnesses, no evidence of it even being seen. But yeah, it should have been there. I totally agree with that. Hopefully DJI's knowledge of possible technical errors with failsafe RTH will help better understand this case and what may have happened. I'll keep you guys updated!

 

[sar104]

Yes, I extensively searched that exact spot and was there before battery would have reached the critical point. So before anyone could've have taken it. I looked right in the spot you put the 3D rendition as it was the last recorded capture I had on my screen. While the scenario you show is exactly what should have happened, it is possible something malfunctioned for it's return beyond that point. If it had stayed, I'd had expected the drone to reconnect signal upon my arrival to that location. Just very strange.... it just disappeared like that in a snap. No witnesses, no evidence of it even being seen. But yeah, it should have been there. I totally agree with that. Hopefully DJI's knowledge of possible technical errors with failsafe RTH will help better understand this case and what may have happened. I'll keep you guys updated!

There is another possibility. You mentioned that winds were calm, but that does not appear to be the case 300 ft AGL, where there was clearly a fairly strong wind from the north. AirData estimates it to have been in the 20 - 25 mph range and that looks consistent with the pitch, roll and yaw data for a couple of periods during the flight when the aircraft was stationary. Given that wind vector, the aircraft may have been blown further south than the direct line back to the home point. It should have cleared the lower Hilton building immediately adjacent to the taller building, but it would not have cleared the grey condo tower to the south of that. That may be worth checking too.

 

[flyhelp]

There is another possibility. You mentioned that winds were calm, but that does not appear to be the case 300 ft AGL, where there was clearly a fairly strong wind from the north. AirData estimates it to have been in the 20 - 25 mph range and that looks consistent with the pitch, roll and yaw data for a couple of periods during the flight when the aircraft was stationary. Given that wind vector, the aircraft may have been blown further south than the direct line back to the home point. It should have cleared the lower Hilton building immediately adjacent to the taller building, but it would not have cleared the grey condo tower to the south of that. That may be worth checking too.

View attachment 91890

Hmm... great point! Tomorrow I'll make calls to the Hilton and the Loft (the gray building) and ask them again if they'd found anything since the drone disappeared on Monday. Hopefully they'll have some info.

 

[Bakersfield Quad]

Remember, in RTH in GPS Mode, the drone will never fly home against 25-30mph. Top speed is 26-31mph, so it would nearly sit still in the headwind and be severely limited in that kind of crosswind.

 

[Meta4]

Remember, in RTH in GPS Mode, the drone will never fly home against 25-30mph. Top speed is 26-31mph.

Top speed in RTH is even less.
It's 22 mph

 

[Bakersfield Quad]

Top speed in RTH is even less.
It's 22 mph

Yeah, I was thinking it would not reach top speed in RTH.

 

[flyhelp]

Yeah, I was thinking it would not reach top speed in RTH.

Maybe - seems like so many things could've happened at this point. At least DJI is investigating it. Hopefully they'll find a solution. It's a big loss for my videos. I'll let you know how it turns out.

 

[sar104]

Maybe - seems like so many things could've happened at this point. At least DJI is investigating it. Hopefully they'll find a solution. It's a big loss for my videos. I'll let you know how it turns out.

DJI has no more data to work with than we do and, not surprisingly it seems, are less interested in figuring out exactly what happened and more concerned with simply determining whether the issue was caused by hardware or software issues and whether they are looking at a warranty issue.

 

[flyhelp]

DJI has no more data to work with than we do and, not surprisingly it seems, are less interested in figuring out exactly what happened and more concerned with simply determining whether the issue was caused by hardware or software issues and whether they are looking at a warranty issue.

Most likely - there must have been a hardware/software issue as even if it did not RTH, it did not stay or land in that area of where it lost connection. I reviewed quite a few obstructed interference cases and the drone should've regained connection when I approached its last location before its battery wouldve shut it off. Its a strange situation overall.

 

[sar104]

Most likely - there must have been a hardware/software issue as even if it did not RTH, it did not stay or land in that area of where it lost connection. I reviewed quite a few obstructed interference cases and the drone should've regained connection when I approached its last location before its battery wouldve shut it off. Its a strange situation overall.

Actually I think a hardware/software issue is the least likely explanation. If it drifted further south due to the local winds then it could have ended up behind other structures or collided with one of those buildings before you arrived at the last recorded position. I will be surprised if DJI accepts responsibility for this one, but it's always worth asking.

 

[KongWerks]

I see major pilot error, huge lack of judgment and total disregard of safety in this scenario.

 

[With The Birds]

I see major pilot error, huge lack of judgment and total disregard of safety in this scenario.

Which of those factors might prove useful in assisting the OP find his AC? I’m sure it’s the files on the SD card that are of highest value to him- good chance of some great footage.

 

[KongWerks]

Which of those factors might prove useful in assisting the OP find his AC? I’m sure it’s the files on the SD card that are of highest value to him- good chance of some great footage.

Part of me is actually kind of hoping he doesn't find it. What happens in Vegas, stays in Vegas.
I'm considering it lost and move onto prevention of losing his next Phantom.

 

[DLynch]

Part of me is actually kind of hoping he doesn't find it. What happens in Vegas, stays in Vegas.
I'm considering it lost and move onto prevention of losing his next Phantom.

Hope you get banned off this forum for saying that

 

[normr]

Did you ever consider setting your RTH altitude higher to take in account the buildings in the area just in case that you lost signal? Wouldn’t it be great if DJI could make the drone RTH following the path it flew before the signal was lost

 

[Northern Canadian]

I'd be happy the police or a lawyer isn't knocking on your door. As they say, forget about it.
New drone laws, regulations go into effect Thursday

 

[Henry Matias]

Very strange, it tried to RTH at least 3 times, you cancelled it once or more. It tried to come home, the distance was getting smaller. But the RTH was set to 98 feet, but you kept taking it up to MAX altitude of nearly 400 feet. There were many warnings of Airspace, GPS mismatches, yet you continued to fly away from home, you must have done it, it was higher than the RTH setting. It appeared to get closer to you several times, but you apparently took control and moved it further from you and higher. Plus you appeared to have attempted to change flight modes, but it must have been set to Single Flight Mode and would not let you.
So, what were you doing all that time, why did you keep flying away from you when trouble started, rather than bringing it home? Seems like you were either very confused or disoriented.
Hope you find it, but I doubt it was a failure, there was nothing there that I saw to indicate that.

I’ve had nothing but issues with my P4p+ wish I never bought it. DJI sent a brand new one from China.... first one was only 4 days old..... any the best Drobe by far with the least issues or none at all for me was the regular P4 that’s my 2cents worth

 

[Northern Canadian]

Hope you get banned off this forum for saying that

Why would you make a remark about banning him? His point isn't inflammatory. The man is allowed an opinion. According to my bit of research, many laws were being broken and this type of activity increases the negative perception of drones and drone pilots. In my opinion, only dealing with a lost drone is minor compared to where this could have gone.
New drone laws, regulations go into effect Thursday

 

[sar104]

I'd be happy the police or a lawyer isn't knocking on your door. As they say, forget about it.
New drone laws, regulations go into effect Thursday

The flight likely failed the criteria for Part 101 and thus became subject to Part 107 which it was not compliant with, but which part of NRS 493.103 are you thinking he contravened?