I got a phone call from one of my pilots the other day, that one of our drones fell from the sky.
He's a trained pilot and certified, so I immediately ruled out cross sticks mid-flight.

I brought the logs into the viewer and two things stood out to me,

The first being a "Strong wind" warning. Which I've been getting almost every time I use DGI Go 4.
Usually, we only fly in Pix4d's Capture app. But sometimes we need to get aerial stills of an area.
Also, I have noticed that almost immediately after takeoff when I use the DJI app, A strong wind warning will display.
Even when the UAV is 20 ft off the ground with a wind speed of 3 m/s. (Which we record off our own weather station)

The second thing I noticed is "GPS Position Nomatch"
I can't find an explanation for this error.

I have the .txt file if someone else wants to take a look and see if im missing something.
But from what I see, it's looking like mechanical failure or some sort.
Any assistance will be greatly appreciated.

Link to Flight

What am I missing?  I see it reducing altitude at about 1 ft. per second.  What altitude was it at when it "fell"?  I see the left stick in the down position when it started coming down-

That's what I noticed too.
The log says its a pretty normal descent.
Yet gravity is 9.8 m/s/s

The drone fell from 40-50 meters AGL.
It was not in autolanding. The pilot was flying all in manual.

Is it the right log we are looking at?

Yup,
This was the only flight that day

Are you sure this is the correct log for the flight  you are describing?  BTW, GPS mismatch warning is not very uncommon. Doesn't mean anything really bad.

Something not adding up...btw I get those stupid wind warnings too when there is hardly a breath.

I just got back to the site today.
I connected the drone to DJI Assistant and got the last dat file.

When DJI Assistant would not display it, I connected the iPad and got the flight logs .txt files off there.
This is the last flight, that there are logs for.
So it would have to be this one.

Would the .text and .dat files have the same data in them?

I have the .dat file too

May be a stupid question but is the drone damaged?

A bit...

I have never crashed my P4P so I am asking....is the damage indicative of a 150 ft. drop?  The landing gear looks intact.  Could the damage have been caused by some other (unbeknownst) mishap?

I was expecting to see the landing gear broken right off.
But instead, they are both cracked and bent.
The props are all broken, including the white connection piece, on one of the arms.
And a few knicks and scratches on the drones foam wetsuit.

I was expecting it to be in pieces when I came in today.
From just looking at it, Id think it fell and clipped a tree, ripping the camera off.

But my pilot said it came down from about 40-50 meters, landing onto a tailings dam.

I know he wouldn't lie.
He and I both just want to know what happened, so I can do an incident report up and hopefully the same can be avoided in the future.

Just can't see how this is the correct log.  Sorry!

Hi, we're sorry to read about the mishap that happens on your drone. If this said drone is under the warranty coverage, you may contact our support using the link below for our team to initiate the investigation about the recent flight. We would recommend syncing the flight records using our DJI Go 4 app, Please let us know if you need our assistance. Thank you for continued support.

www.dji.com/support

Thanks DJI Tony,

Luckily it is under warranty still.

I was just talking with DJI Support and they linked me with a local DJI dealer.
Im going to send the drone to them today and wait for them to get a hold of me.

Thank you to everyone who replied.

Quite the mystery.  I would be very interested in the findings at the dealer.

I'll post here as soon as I get any info.

I just brought the drone to our warehouse for shipping and it should be sent off-site in the next hour.
Hopefully, I'll get word in the next day or two what the issue/malfunction was and ill post the findings here.

JCarignan Posted at 2-26 08:15
Thanks DJI Tony,

Luckily it is under warranty still.

You are very much welcome JCarignan. If you have any other inquiries or concerns with DJI. Please feel free to post it here at DJI Forum we are all here to help you. Thank you.

Sorry to read that mate

please keep us posted

Sorry to know that buddy

Still waiting to hear from the DJI associated company in Woodbridge Ontario.
The drone should be there by now.

JCarignan Posted at 2-26 07:48
I was expecting to see the landing gear broken right off.
But instead, they are both cracked and bent.
The props are all broken, including the white connection piece, on one of the arms.

But my pilot said it came down from about 40-50 meters, landing onto a tailings dam.
The log supplied doesn't show any landing or crash.
It ends back at the launch point with the drone six feet above the ground and the throttle held hard down.
Despite a lot of full down on the throttle during the last 4 seconds, the altitude has not reduced.
That looks like a hand catch landing?

That leaves a mystery of what happened between being coming to just six feet off the ground and getting back to 40-50 metres that your pilot says it fell from?
You need to get more information from your pilot because the full story hasn't shown up here so far.

One explanation might be a second flight for which the flight record in the app was deleted?

Sommat does not add up, the damage looks like it came down upside down  but the props were still spinning, that much that hitting the ground wasnt enough to stop the props, they were still going looking at the scuffs from them, that would explain the little damage to the legs but not the whole episode, Labroides sound realistic, it was a bad hand catch,, and some of the damage may, only may, have been caused to make it look like something worse happened? thats only speculation, i take it it was not recording video at the time? as you can see from the image below, the landing was a gently slope, not a drop

Labroides Posted at 3-2 19:10
But my pilot said it came down from about 40-50 meters, landing onto a tailings dam.
The log supplied doesn't show any landing or crash.
It ends back at the launch point with the drone six feet above the ground and the throttle held hard down.

One explanation might be a second flight for which the flight record in the app was deleted?

Is that possible?!

Can the records be manipulated like that?

I came across this thread:

Missing Logs

Is it known if this is still an ongoing issue?
Perhaps that could explain why the log appears to be wrong. Even though that was the last log.

I would have a talk with the pilot and see if he may have deleted the correct log, maybe by accident.

Hey guys, I just wanted to give an update - because I finally got one today!

Heres the email I got:

Hello Jason,

DJI has discontinued the P4P and it is no longer for sale, you can basically only get them from third parties that may still have stock or used.
However, this isn’t what is causing the delay. I am working with the DJI back office to see why the flight data cannot be read. We have elected to ultimately ship your unit to DJI’s repair facility in LA. Your unit is currently in transit there and the technician there will be able to do more with it than what I can do here.

If DJI can confirm the case to be warranty related, they will replace the drone for you. They still have stock to do that. This isn’t supposed to take this long normally and I apologize about that. Your case is a bit unique because we’re unable to pull useable flight data from the aircraft. This is what is causing the delay.

I will definitely keep you informed as to what is going on with the aircraft as I hear back from DJI.


So from that I get from it, the last flight - which I initially posted above, is not the flight that caused the crash.
That a flight afterward's, that they cant usable flight data from, holds the key.

I was told to send my P4P to a DJI licensed repair facility.
But they lack the ability to pull the data, so someone in LA is gonna give it a try.

Hopefully, I get some news soon.

The DJI Mavic 2 Pro - although im sure is a fine machine for photography, will not cut it for photogrammetry.
Ive had my purchasing department searching the net, trying to find another P4P to purchase in the meantime. But no luck yet.

As soon as I get more news ill post it here.

Hope you get it sorted out.

UPDATE:
I got word back from a 3rd party on behalf of DJI.
They are not going to cover the repair cost of $1100 CDN even though its under warranty.

No problem, I placed a purchase requisition and sent them the repair cost.
But the question still loomed, what caused the crash?
So I asked the agent what was the cause of the crash and he replied they didnt know.

They dont know I said? Yet you can determine that the repair shouldnt be covered under warranty?
This was the email response I got from the 3rd party:

Hello Jason,

DJI has been unable to determine any cause of the accident. They are unsure if it is a failure to do with the data recorder or something else.

So I wrote back to him with something along the lines of "if they cannot determine what happened, how did they come to the conclusion that it shouldn't be covered under warranty."
They've had the drone for quite some time now.
I made this post back on February 26, 2019. It's now May 22, 2019.

Is it because the P4P is discontinued and they dont have any to replace mine with?
Keep in mind this is a 3rd party im dealing with. So I asked him, whats my case number, im going to contact DJI directly and ask them what happened.
As a large company, it is important we know what happened to cause the drone to crash. For safety reasons and of course to not repeat that action.

I contacted DJI.
The long and short of it, they said they don't know, and that's something I have to discuss with the 3rd party.

I copied my conversation with the agent and emailed that to the 3rd party were stuck dealing with.
And the run around continued.
I tried sending them an email today to see if they found out anything, and my email bounced back with "Im on vacation till next month"

So that's where we are now.
The run around from DJI and the 3rd party company Multirotorheli.
Each saying ask the other, with no one able to provide an answer as to what happened.