My P3P crashed, DJI not cooperating

[Chris_P]

These are scuff marks on the bottom of three of the four arms... again from the cartwheel motion I described.

 

[Chris_P]

I also downloaded the .DAT files directly from the drone. Does anyone know how to open or examine those? They are much bigger and may have more info. I offered to send them to DJI but they said the txt files from the ipad was all they needed.

 

[tytlyf]

Like I said, the GPS coordinates compared to the map don't show it going to the trees but right to the rocks. So you got that going for you. The only other thing I can think of is if you do hit the throttle between that 20m threshold that it screws up the altimeter readings in the software. Maybe it screws with the altitude readings and it's automatic functions? Weird stuff. I'm busting out google maps, street view and the such. I feel like a private investigator, hah

 

[Oso]

I also downloaded the .DAT files directly from the drone. Does anyone know how to open or examine those? They are much bigger and may have more info. I offered to send them to DJI but they said the txt files from the ipad was all they needed.

You can try the DatCon tool created by @BudWalker

DatFile.net

 

[ferraript]

I also downloaded the .DAT files directly from the drone. Does anyone know how to open or examine those? They are much bigger and may have more info. I offered to send them to DJI but they said the txt files from the ipad was all they needed.

that's great, I was going to ask you if your P3P is working so you could retrieve the DAT flight log
as Oso wrote, you can use the DAT converter to get CSV file
it contains barometric altitude but also GPS altitude, so we can see the difference

 

[Sealybomb]

You will not crash. I'm telling you this thing is rock solid In the air. You can comfortably fly it over just about anything you want. Remember this, DJI owns about 70% of the drone market. For every X Star Premium or Typhoon H sold there are probably 50 Phantoms. So you will see more crashes reported more problems reported its just math. Go fly your bird and don't worry about it.

Thanks for the tip! Gonna be careful and stuff while learning but I'm not gonna treat it like a ...you know what I mean [emoji23] I'm gonna fly it and looking forward to seeing what this baby can do!!


Sent from my iPad using PhantomPilots mobile app

 

[MikeyOnline]

I still wonder if it's possible that your perspective from the boat affected what you saw versus what happened. Two independent sensors corroborate that the AC started spinning wildly during the last 2 seconds of flight and indicate that it lost about 45 feet of altitude (basically straight down) during those 2 seconds. From your vantage point, that could have looked like it drove itself straight into that rock but I think it unlikely that both the baro and the Z axis sensors (which I believe are independent) say it dropped 45 feet in 2 seconds right at the end of the log. I know I've been confused more than once into thinking it's taking a straight line when it is really falling, particularly when it is moving basically in a straight line away from you. If the map is accurate to the level we think it is, that still points to a possible hardware failure in my eyes. If it started spinning wildly and dropped from the sky in open air, the only thing I can think of is an Esc failure (based on the stick input, it doesn't look like CSC is involved). Which I think you could pose as an argument to DJI. Given the data, I can come up with no explanation other than a bird strike or a hardware failure that would cause what I'm seeing in the log and on the map. If that were my bird, I'd have to argue to DJI that (regardless of what you saw) the log indicates that it spun out of control while at about 54 feet altitude, and dropped out of the sky. That's not just a "buttered up" excuse. That's what I see in the log.

Keep in mind that I'm not one of the log-pros on this forum. I'm just going by the CSV log file. Maybe someone who has access to the full log can look at motor speeds and other parameters to corroborate (or contradict) what I'm seeing. I'm pretty new to log diagnosis so maybe I'm all wet but to me it looks like the thing had a hardware failure near that shoreline.

Mike

 

[Chris_P]

Thanks for your assessment and input Mike. I was watching this from less than 100' away. There is no way the drone was at 54 or 45 feet. The only reasonable explanation is an incorrect altitude reading by the drone which contributed to this crash. It flew into the rock front on at no more than 10' above the water cartwheeled and fell in the water. That sequence is deeply etched in my mind ! It was a horrible day. I have converted the DAT files from the drone to CSV and uploaded here ... maybe someone can make sense of that.

Dropbox - FLY046.csv

 

[MikeyOnline]

Well that certainly has all the data. You can see where it flew straight into the rock, both front motors go to zero RPM, and then it tumbles a bit. Even the GPS altitude shows a 40 foot drop after it hit the rock but I think what might have happened is that it rolled into the water at that point and maybe the water contaminated the readings, making it look like it "fell" 40 feet but in fact, the readings were just corrupted at the end due to the water entering the electronics. Unless that rock was 30-40 feet tall (doesn't look like it), it does look like the altitude reading was just "off". In such a case, does anyone know if DJI makes any allowance for that: a crash due to a bad altitude reading, causing the AC to return home much lower than it should? I don't know if they cover that.

Mike

 

[Chris_P]

Thanks again Mike for your assessment. Thank God for these logs. Funny thing is I offered to send these to DJI and they said they don't need them. Good to know the company who makes the aircraft doesn't care enough to have all the info when assessing a warranty claim !

 

[msinger]

Funny thing is I offered to send these to DJI and they said they don't need them.

In your original post, you said you already sent your logs to DJI. Which logs did you send to them?

 

[Chris_P]

In your original post, you said you already sent your logs to DJI. Which logs did you send to them?

The ones from the DJI GO app on my iPad. I copied them out using iTunes. Those are txt documents. These are DAT files directly from the drone. I used the DAT to CSV converter someone suggested in an earlier post.

 

[msinger]

The TXT and DAT logs both indicate you hit a tree. I don't think they'd come to a different conclusion with the DAT log in hand.

 

[Chris_P]

I posted the Google earth photo generated from the logs. There are no trees anywhere the point of impact. I saw this happen, there was no contact with a tree. It flew directly into the rocks and the altitude reading was wrong.

 

[msinger]

I posted the Google earth photo generated from the logs. There are no trees anywhere the point of impact. I saw this happen, there was no contact with a tree. It flew directly into the rocks and the altitude reading was wrong.

I understand what you're saying. However, your logs tell a different story.

 

[Chris_P]

With all due respect, there are others who have read the logs and think differently. The Google earth photo is proof that there are no trees nearby. The flight path is plotted from the boat where I was attempting to land directly to the rocks. I understand DJI and their affiliates may suggest otherwise for obvious reasons but the Google earth photo speaks for itself. The only info that suggests any contact with a tree is the unexplainable sudden altitude drop which is pure speculation.

 

[msinger]

With all due respect, there are others who have read the logs and think differently.

With all due respect, I am simply telling you what your logs are saying. I am not assuming you hit a tree, that you really forgot to set your RTH altitude to 50m prior to the flight, that you did not reset the home point multiple times during your flight, etc. Furthermore, I do not work for DJI nor do I side with DJI for any reason that does not make sense. All opinions are my own.

 

[henick]

My only problem with what you remember is that during stressful situations people tend to remember what they want even if the blanks are filled in from faded memory. Perspective plays a big part and regardless of what you saw, the logs are what you and DJI have to go by so as a bit of advice (not that you asked for it -- sorry) I'd try to find a hook to make them investigate further.

Being nice to people who can help you find that angle here like msinger, is probably in your best interest. You can always call DJI back and roll the dice with a new rep.

Good luck.

 

[Chris_P]

Thank you and I am certainly trying to do that. I've posted everything available to me to the public forum hoping for some answers. I've looked at the logs myself and although I'm no expert, the flight path plotted by these very same logs show it flew directly into the rocks in an area where there are no trees. This info IS from the very logs we are referring to. So yes, I do take offence to the suggestion that I'm fabricating data when I'm getting my information from the same logs.

Others have suggested the tree scenario but after viewing the CSV logs they have also said that they agree it flew directly into the rocks. Looking at the location of the trees, any reasonable person would realize that flying at the trajectory outlined in the logs, hitting those trees, which are probably 40' from the shoreline, the drone would have fallen directly down and would have crashed on land, not in the water. The momentum would have pushed it further inland away from the waters edge.

 

[Chris_P]

One more small bit of evidence. I've attached a pic of my camera. Bear in mind I have a camera guard installed on the P3P. This damage occurred when it hit the rock head on. I doubt falling from a tree could do this .....