Crash Diagnosis Thread

Did you at any point notice this message appear on your device screen?

"Ultrasonic Systems Error. Land As Soon As Possible."

I converted your flight log and looking at it when I get the chance.
I certainly did notice it and that was shortly before I lost all visual from the camera. I guided it home immediately via GPS until the GPS map went haywire (which is clearly shown on the log), after seeing that message. Again with all the speed and compass errors as well as the above clearly it was a massive hardware failure on the P3 yet all DJI would say is that wind that kept it from coming home. Gee, funny how they failed to mention all the failure messages or the fact it read I was going 3,000 mph at some points. Again, if it was wind why did it fall out of the sky with 30% battery? They are crooks.
 
Could you post the .DAT file form the flight where you crashed? I have tried analysis of logs before to help understand what's going on and I know that many, many old hands from this forum are expert in crash analysis and can absolutely identify the cause of the crash.

We did an analysis of one guy's flight once where he reckoned the craft dropped from the sky like a stone. Indeed it did, but only because he was holding the left stick fully down. He got the control inputs wrong and in the confusion blamed the aircraft. The log files tell the truth. Always.

I have had a few crashes myself - lost two phantoms into the water (both total losses) and initially I thought they must be the aircraft's fault (after all, how could I be wrong, sure I'm the best pilot in the world, am I not?) but post incident analysis by others (and by me) usually revealed that the pilot was the real reason for the crash.

I've been haunting these forums for well over three years now, and it still amuses me when I see posts from (quite often, but not always) newbies who simply will not accept that they might be at fault and refuse assistance that would (probably) end all speculation by interrogation of the flight logs.

BTW, I'm on all the latest firmware (usually am) and I have not experienced any issues.
Well I did upload my flight log a couple days ago. Care to look at it and comment or was there another reason you wrote the above.
 
Did you at any point notice this message appear on your device screen?

"Ultrasonic Systems Error. Land As Soon As Possible."

I converted your flight log and looking at it when I get the chance.
Thanks Frank. Another guy or two on here said they'd try to help me but you are so far the only one who's looked at the logs. Thanks in advance and I look forward to hearing what you think.
 
Did you at any point notice this message appear on your device screen?

"Ultrasonic Systems Error. Land As Soon As Possible."

I converted your flight log and looking at it when I get the chance.

Oh my......and here's some more error messages spotted.

"SpeedErrorLarge"

There should have been enough visually take place that this aircraft should have been landed right away.
 
Thanks Frank. Another guy or two on here said they'd try to help me but you are so far the only one who's looked at the logs. Thanks in advance and I look forward to hearing what you think.

Based on data details I've seen in the TXT file shows me the DAT file will have a more defined details on what actually took place. And @BudWalker in my opinion is one of the better ones out there to diagnose the DAT flight log.
 
Well I did upload my flight log a couple days ago. Care to look at it and comment or was there another reason you wrote the above.

I see that it is just a txt file - the DAT file is the one that gives the most information. Do you have the phantom? I would be happy to try and decipher the DAT file if you can retrieve it.
 
I see that it is just a txt file - the DAT file is the one that gives the most information. Do you have the phantom? I would be happy to try and decipher the DAT file if you can retrieve it.

1crash2.jpg



As it turns out his crash is just like the others as of late. There is a lot of unknowns surrounding this flight. It appears to of had issues almost from the start. Had it been brought back the 1st sign of a problem this crash would not have taken place.

If error messages look serious, it might be better to land it and go pick it up then have something like this take place. If others have been recently posting about crashing, you might prepare yourself for this to happen if you don't take precautions. Notes to take are what firmware versions are experiencing these issues. If you also have that version, then as I say be prepared.
 
I see that it is just a txt file - the DAT file is the one that gives the most information. Do you have the phantom? I would be happy to try and decipher the DAT file if you can retrieve it.
No. Unfortunately it went down in a heavy forest and since the GPS went haywire long before it crashed it's irretrievable.
 
View attachment 62859


As it turns out his crash is just like the others as of late. There is a lot of unknowns surrounding this flight. It appears to of had issues almost from the start. Had it been brought back the 1st sign of a problem this crash would not have taken place.

If error messages look serious, it might be better to land it and go pick it up then have something like this take place. If others have been recently posting about crashing, you might prepare yourself for this to happen if you don't take precautions. Notes to take are what firmware versions are experiencing these issues. If you also have that version, then as I say be prepared.
In one of my earlier post I reported that's exactly what I did. As soon as I received the ultrasonic error I high tailed it back home. Unfortunately the drone had other ideas. But again, according to DJI, it was wind. :rolleyes:
 
View attachment 62859


As it turns out his crash is just like the others as of late. There is a lot of unknowns surrounding this flight. It appears to of had issues almost from the start. Had it been brought back the 1st sign of a problem this crash would not have taken place.

If error messages look serious, it might be better to land it and go pick it up then have something like this take place. If others have been recently posting about crashing, you might prepare yourself for this to happen if you don't take precautions. Notes to take are what firmware versions are experiencing these issues. If you also have that version, then as I say be prepared.
Let me ask you this Frank, Without access to the DAT file and just based solely on the flight log would you agree wind had zero to do with this crash? And would you also agree this drone experienced serious failure?
 
Is this now a crash analysis thread?
Love the irony. Goes into a thread titled
Increase in the number of crash threads recently
and complains of the crash analysis. Do you also touch hot stoves to make sure they are hot?
 
@Jnnyr I looked the .txt for this flight. This incident probably has a lot to do with a gps problem. Although the number of satellites remained at 16 the gpsHealth dropped from 5 to 0 and then back to 3 at 531 seconds.
upload_2016-8-22_12-5-59.png

Here the gpsHealth is plotted with the green line. The light green/teal background shows the GoHome that was issued either by the pilot or the P3. But, the P3 just remained where it was. The very tail end of this flight was showing a Lat/Long of [0.0, 0.0] indicating that it had no GPS info.

I understand DJI is telling you that wind was the problem. IMO this is total nonsense.

Without the .DAT this is about as good as I can do.
 
Thanks for this file. They have recently changed the firmware without letting anyone know. The best option may be to go back to older firmware. That will help keep this dropping from the sky issues taken care of at least until they get a revision in place.

Don't forget to set your GO app device so that the app can NOT be updated. Otherwise may never know what changes they add to your setup.
If we go back to the 1.8.80, do we keep the latest RC update?
 
@Jnnyr I looked the .txt for this flight. This incident probably has a lot to do with a gps problem. Although the number of satellites remained at 16 the gpsHealth dropped from 5 to 0 and then back to 3 at 531 seconds.
View attachment 62874
Here the gpsHealth is plotted with the green line. The light green/teal background shows the GoHome that was issued either by the pilot or the P3. But, the P3 just remained where it was. The very tail end of this flight was showing a Lat/Long of [0.0, 0.0] indicating that it had no GPS info.

I understand DJI is telling you that wind was the problem. IMO this is total nonsense.

Without the .DAT this is about as good as I can do.
I really do appreciate your input Bud. I am quite technical and even at a cursory glance at my flight log (nevermind the actual experience), I already knew the 'wind' causation was laughable. Unfortunately, without the drone, I am not in a position to have the .DAT file examined. Honestly, it wouldn't really matter as they seemed to have little problem lying to my face about my crash so I doubt the .dat file would change that. Well, thank you very much for confirming what I suspected. I guess I really have no recourse even though I was still under warranty. For anyone that is on the fence about what to buy next let mine be a cautionary tale.
 
Jnnyr, how did DJI come to the conclusion your P3 crashed because of high winds?

It's obvious from the .txt file which I assume they had, there were system problems, so it doesn't make sense how they concluded high winds crashed you? Just curious as something seems missing.
 
Jnnyr, how did DJI come to the conclusion your P3 crashed because of high winds?

It's obvious from the .txt file which I assume they had, there were system problems, so it doesn't make sense how they concluded high winds crashed you? Just curious as something seems missing.
I'd love to know the same thing Mocho. I have no idea. That is the least plausible explanation especially when you consider the drone went down with 30% battery. They won't elaborate and keep closing my multiple support tickets saying they were 'resolved'. That actually is their number one technique for ridding themselves of us annoying customers.
 
I really do appreciate your input Bud. I am quite technical and even at a cursory glance at my flight log (nevermind the actual experience), I already knew the 'wind' causation was laughable. Unfortunately, without the drone, I am not in a position to have the .DAT file examined. Honestly, it wouldn't really matter as they seemed to have little problem lying to my face about my crash so I doubt the .dat file would change that. Well, thank you very much for confirming what I suspected. I guess I really have no recourse even though I was still under warranty. For anyone that is on the fence about what to buy next let mine be a cautionary tale.
My impression of DJI isn't so negative. Analyzing a lot of flights I sometimes get to know the final disposition. Usually, DJI is better than this. I think that it depends on who you talk to a DJI. If I were you I'd keep at them. Try to talk to someone different, i.e. go around the person you were talking to. It should be easy to get to a point where it's clear it wasn't wind and was the gpsHealth issue I described.

The problem that you'll have is that a low gpsHealth could be due to factors unrelated to the P3 hardware. I'd argue that the fact it abruptly dropped to 0 and then never recovered makes it more likely the problem was on the P3.
 
I'd love to know the same thing Mocho. I have no idea. That is the least plausible explanation especially when you consider the drone went down with 30% battery. They won't elaborate and keep closing my multiple support tickets saying they were 'resolved'. That actually is their number one technique for ridding themselves of us annoying customers.

Well I sure understand why you are upset! They should still be able to back up what they are saying, regardless if they are right or wrong!

I mean where does the wind even come into play with the data set you gave them?
 
@Jnnyr I looked the .txt for this flight. This incident probably has a lot to do with a gps problem. Although the number of satellites remained at 16 the gpsHealth dropped from 5 to 0 and then back to 3 at 531 seconds.
View attachment 62874
Here the gpsHealth is plotted with the green line. The light green/teal background shows the GoHome that was issued either by the pilot or the P3. But, the P3 just remained where it was. The very tail end of this flight was showing a Lat/Long of [0.0, 0.0] indicating that it had no GPS info.

I understand DJI is telling you that wind was the problem. IMO this is total nonsense.

Without the .DAT this is about as good as I can do.

Bud how is GPS Health determined? Especially considering the bird is showing lots of sats. connected ?

TIA
 
Bud how is GPS Health determined? Especially considering the bird is showing lots of sats. connected ?

TIA
Don't know the answer to that. It's computed by the P3 and has a range of [0, 5] with 5 being the best. 4 is marginal. Anytime it's 3 or below the P3 will drop into ATTI and have trouble navigating.

I'm not a GPS expert but in addition to number of satellites there are other factors that will influence accuracy. HDOP (Horizontal dilution of precision) and VDOP (vertical dilution of precision) are some of those factors.
 
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