To preface what is going on currently with my Phantom 4 Pro v2: I was conducting a aerial surveying mission this tuesday (10/19) and noticed that the drone had veered hard to the right after takeoff but it was only for a brief second and then it corrected and ascended to the flight that was entered for the flight. I use pix4dcapture for all of our flights as we then use pix4dmapper to process all the data.
During all of my flights with this program, when the drone reaches 19% battery life, it automatically flies back to the RTH position and lands without any issues. However, this particular flight the drone did not begin its return once it reached 19% so I immediately noticed this and manually returned it. It flew back to the RTH location and hovered for about a half second and then took off to the right at full speed. Upon noticing this I shut down the pix4d app and selected the RTH on the DJI GO app itself but this did not do anything to its path. I cancelled the RTH and tried to takeover manually. I managed to manuever the drone back to where I was standing but it was fighting against my input the whole time. If i let go of both joysticks it would still continue to move. It eventually alerted me that the battery was critically low (10% and the drone was right in front of me so that was confusing) and it was going to perform an emergency landing (i believe, I was in panic mode at this point). At this time the drone no longer responded to my input and continued to fly full speed to my left while steadily descending and eventually crashing into a pile of dirt/rocks.

I recovered the drone some 150-200 feet away from me and assesed the damage which was a cracked middle shell where the drone body meets the landing gear and broken right landing gear. I have since replaced both of these items and reassembled the drone myself ( i took pictures of all parts while disassembling and made sure it went back together exactly how it was before).

Upon completing the reassembly I took the drone out for a test flight with a full battery and new props. The drone didnt require a compass calibration as it usually does when I fly, and I then took off as everything was green and ready to go. The drone rose to the takeoff height of 4 feet and immediately flew dead right at full speed (not increasing in height) and I had to stick down essentially crash it into the grass (the grass is long and the drone seemed to be fine after it landed.) I did this once more and got the same result.

While I initially thought this was a problem I only encountered after I reassembled the drone, it seems like this problem was present in my mapped flight on 10-19 of this week but didnt surface until it was landing. Any help would be greatly appreciated as I am thoroughly confused as to whats going on with it currently. I have opened a case with DJI and plan on sending it in but this forum seems like a good place to address any issues that may be able to be resolved by myself.

Also, these are the flight logs from the two test flights (both on 10-21-21) and the initial crash flight (10-19-21).

Thank you

Hi, thank you for reaching out. We're sorry for the unpleasant experience. In this kind of situation, I'm afraid that you may consider sending the unit in for a proper diagnosis. You can contact our support team to start up a ticket at https://www.dji.com/support. Also, the warranty can be applied depending on the outcome of the damage assessment including the warranty period of your unit. Thank you for your understanding and support.

I once had a similar experience with my P4 standard, a few years ago. Using nothing other than the DJI Go4 App at the time. The drone developed a mind of its own and set off full tilt in a random direction when on its way back to the homepoint.  I wrestled with the controls for several minutes before managing to crash-land it in a ploughed field about 100 metres from me. It was fortunately muddy and the drone incurred only one damaged prop - an easy replacement.   I never got to the bottom of the problem. The drone was fine for the next flight, and subsequently.

Probably not your issue..but..
Did you wait for the home point to be recorded correctly?
Did you calibrate compass and check IMU?

It always bothers me that people fly their batteries to 19%. REMEMBER, at 3.7volts per cell, it is considered to be a DEAD lipo, and you should be on the ground. I don't know what's DJI 19% is, but it is way below 3.7v a cell. All of this comes from my 13+ years in RC. I've puffed batteries driving them low. More info here: https://droneflyingpro.com/why-is-my-drone-battery-not-charging/

I had issues with Pix4D too at times.  The drone wouldn't land and the controls were I think Mode 1 or 3,4.  It was anything but Mode 2.  Go4 wouldn't respond I think and the only thing I could do was Pix4D RTH.  Luckily that landed it.  This happens at times when calibrating near magnetic interference and it passing when it shouldn't have passed.

delfin2003 Posted at 10-23 09:48
Probably not your issue..but..
Did you wait for the home point to be recorded correctly?
Did you calibrate compass and check IMU?

Did you calibrate compass and check IMU?
There is no need to calibrate the compass before a flight.

Labroides Posted at 10-24 15:49
Did you calibrate compass and check IMU?
There is no need to calibrate the compass before a flight.

DJI ask me to calibrate many times Across all drones but the Inspire 1 but I hardly take-off from the same place more than once or near the same place.  

AntDX316 Posted at 10-25 01:01
DJI ask me to calibrate many times Across all drones but the Inspire 1 but I hardly take-off from the same place more than once or near the same place.

DJI ask me to calibrate many times Across all drones
DJI are the last people to listen to about compass calibration.
Their manuals have been full of compass misinformation and myths from the beginning.

but I hardly take-off from the same place more than once or near the same place.
That's completely irrelevant to the compass.
And as I said ... there is no need to recaliubrate your compass before a flight.

Labroides Posted at 10-25 02:36
DJI ask me to calibrate many times Across all drones
DJI are the last people to listen to about compass calibration.
Their manuals have been full of compass misinformation and myths from the beginning.

It ask and you can't take off.  If you are taking off in areas that don't have a lot of iron or traveling too far then you may never have to calibrate.  It says it has to be calibrated or else it won't take-off.  I have jobs in urban, suburban, etc.  The places can be at least 40 minutes away in all directions.  Some, 2 hours+.

Inspire 1 never asked to calibrate even when I had it shipped to me from someone near or in California.  I calibrated anyway to be safe.

I even calibrate w/ the P4PV2 and it says pass but definitely near iron or w/e is causing interference.  With Pix4D, it doesn't take-off all the way and just hovers.  Sometimes I have to keep calibrating near the area because there is no place no place on the roof to take-off from but that super small area.  It's dangerous like this though because it doesn't respond to your controls or when it does its like in Mode 1, 3, or 4 which can be ultra sketchy and dangerous when near walls, fences, or other objects as high as it's hovering.  Switching to Go4 doesn't work, have to hit RTH on the Pix4D which makes it land.

I really want to get out of the drone business but it never really fails.  I get worried one day it might drop causing heavy damage but at least it's not an Inspire 1 in the air.

I was having issues w/ the M2P one time.. really 100% thought I lost the drone, was thinking what I was going to do with what ever it hit when they investigate and I get a phone call later.  I checked everything and was Certain nothing was near at the altitude I was orbiting.  I was in the vehicle ready to leave.  Luckily, it came like 10 minutes later which was how long I was waiting before determining to leave.

AntDX316 Posted at 10-25 02:45
It ask and you can't take off.  If you are taking off in areas that don't have a lot of iron or traveling too far then you may never have to calibrate.  It says it has to be calibrated or else it won't take-off.  I have jobs in urban, suburban, etc.  The places can be at least 40 minutes away in all directions.  Some, 2 hours+.

Inspire 1 never asked to calibrate even when I had it shipped to me from someone near or in California.  I calibrated anyway to be safe.

It ask and you can't take off.  If you are taking off in areas that don't have a lot of iron or traveling too far then you may never have to calibrate. '
It says it has to be calibrated or else it won't take-off.
If you understand what compass calibration actually does, you'd also understand why there's is no need to recalibrate the compass before flying.
If you are too close to steel objects, your compass warns you, but recalibrating won't ever fix the problem and is not needed at all.
The proper action is to power off and move away from the steel that the compass is warning about.

I have jobs in urban, suburban, etc.  The places can be at least 40 minutes away in all directions.  Some, 2 hours+.
That's completely irrelevant.
Distance from last flight and wherever you are in the world makes no difference.
There is no need to recalibrate the compass before flying.

Inspire 1 never asked to calibrate even when I had it shipped to me from someone near or in California.  I calibrated anyway to be safe.
No ... you calibrated it because you don't know what compass calibration does and when it might be needed.

Labroides Posted at 10-25 03:42
It ask and you can't take off.  If you are taking off in areas that don't have a lot of iron or traveling too far then you may never have to calibrate. '
It says it has to be calibrated or else it won't take-off.
If you understand what compass calibration actually does, you'd also understand why there's is no need to recalibrate the compass before flying.

So you want to avoid calibrating when it says Has to be calibrated or you can't take off?  Why even challenge it and not just do it?  Spin around in a circle with it flat, then sideways and boom done.  You could be missing something important and want to ignore the "warning".  People have had stuff go wrong in other areas of life by not truly knowing what the "warnings" mean such as the newly young hired people on that big drop amusment park ride that didn't strap the 6 year old in properly, turned the warning off, she fell off the ride and died.  Just as the final "warning" check of not pointing a gun that was even deemed safe at anybody and pulling the trigger like Alec Baldwin killing 1 and critically injurying but currently stable another.  I mean, if the people who have died made it into a better afterlife, they are in a better position than all of us grinding out with all kinds of arguments and challenges that have to be settled multiple times per day every single day while alive on Earth in order to live.

Pix4D wouldn't even allow a complete take off (hovering around 5' only) if it passed but then detected it needs to be calibrated again (but doesn't tell you) which is good.  It says Compass Redundancy Switch in flight at times.  No idea if it would have lost complete direction of itself if it only had 1 Compass.  Had a time where I was flying the Inspire 1 and the Compass errored briefly in flight but it was due to the fact I turned the angle limits up so it was flying quite faster than expected.

You could probably circumvent the problem entirely by disabling it through firmware or software (always pass, no checks).  You could probably get away with hand launching high up but if anything goes wrong and it gets us killed then it was good we listened to you (an expert we "believed") if a better afterlife was made.

It's not entirely the same like having an e-scooter go as fast as you want while the rented e-scooters limit you down to 6mph or less in certain areas.  That is discretionary.  Hardware problems could make the things we use confused and what we want it to do, it doesn't, like a body that has medical issues like uncontrolled muscle spasms.

AntDX316 Posted at 10-25 10:09
So you want to avoid calibrating when it says Has to be calibrated or you can't take off?  Why even challenge it and not just do it?  Spin around in a circle with it flat, then sideways and boom done.  You could be missing something important and want to ignore the "warning".  People have had stuff go wrong in other areas of life by not truly knowing what the "warnings" mean such as the newly young hired people on that big drop amusment park ride that didn't strap the 6 year old in properly, turned the warning off, she fell off the ride and died.  Just as the final "warning" check of not pointing a gun that was even deemed safe at anybody and pulling the trigger like Alec Baldwin killing 1 and critically injurying but currently stable another.  I mean, if the people who have died made it into a better afterlife, they are in a better position than all of us grinding out with all kinds of arguments and challenges that have to be settled multiple times per day every single day while alive on Earth in order to live.

Pix4D wouldn't even allow a complete take off (hovering around 5' only) if it passed but then detected it needs to be calibrated again (but doesn't tell you) which is good.  It says Compass Redundancy Switch in flight at times.  No idea if it would have lost complete direction of itself if it only had 1 Compass.  Had a time where I was flying the Inspire 1 and the Compass errored briefly in flight but it was due to the fact I turned the angle limits up so it was flying quite faster than expected.

What on earth was all that about? A complete load of irrelevant hogwash. Get off here!

AntDX316 Posted at 10-25 10:09
So you want to avoid calibrating when it says Has to be calibrated or you can't take off?  Why even challenge it and not just do it?  Spin around in a circle with it flat, then sideways and boom done.  You could be missing something important and want to ignore the "warning".  People have had stuff go wrong in other areas of life by not truly knowing what the "warnings" mean such as the newly young hired people on that big drop amusment park ride that didn't strap the 6 year old in properly, turned the warning off, she fell off the ride and died.  Just as the final "warning" check of not pointing a gun that was even deemed safe at anybody and pulling the trigger like Alec Baldwin killing 1 and critically injurying but currently stable another.  I mean, if the people who have died made it into a better afterlife, they are in a better position than all of us grinding out with all kinds of arguments and challenges that have to be settled multiple times per day every single day while alive on Earth in order to live.

Pix4D wouldn't even allow a complete take off (hovering around 5' only) if it passed but then detected it needs to be calibrated again (but doesn't tell you) which is good.  It says Compass Redundancy Switch in flight at times.  No idea if it would have lost complete direction of itself if it only had 1 Compass.  Had a time where I was flying the Inspire 1 and the Compass errored briefly in flight but it was due to the fact I turned the angle limits up so it was flying quite faster than expected.

So you want to avoid calibrating when it says Has to be calibrated or you can't take off?
Yes  

Why even challenge it and not just do it?
Because I understand what compass calibration does and when (almost never) it might be required.
I understand how the compass works and that DJI's warning message is badly worded to make people like you think that calibrating the compass is needed.
No amount of compass calibration can fix the problem, if the problem is that you are launching from a manhole cover.

People have had stuff go wrong in other areas of life by not truly knowing what the "warnings"
Drone flyers would fly safer if they understood how their compass worked rather than following DJI's misleading compass information.

The rest of your post is irrelevant and just shows that you have no understanding of your drone's compass.

Labroides Posted at 10-25 13:27
So you want to avoid calibrating when it says Has to be calibrated or you can't take off?
Yes  

According to your compass knowledge expertise, disabling all compass calibration checks on all your DJI drones in Any area of the world would be ok?  It would be cool if a DJI engineer could come here and tell us Why it has to be calibrated.  I'm not sure how it can tell exactly when I'm over or near magnetic interference but nearly every time it makes sense and it "knows".

AntDX316 Posted at 10-26 16:09
According to your compass knowledge expertise, disabling all compass calibration checks on all your DJI drones in Any area of the world would be ok?  It would be cool if a DJI engineer could come here and tell us Why it has to be calibrated.  I'm not sure how it can tell exactly when I'm over or near magnetic interference but nearly every time it makes sense and it "knows".

According to your compass knowledge expertise, disabling all compass calibration checks on all your DJI drones in Any area of the world would be ok?
If the compass is calibrated, it's calibrated for everywhere because compass calibration has nothing to do with your geographic location.
It would be cool if a DJI engineer could come here and tell us Why it has to be calibrated.

That's never going to happen, but I can tell you.
Your compass has to be calibrated so that it reads properly and isn't afected by the magnetic fields that are part of the drone.
Once that's done, it's done and doesn't change unless you add or remove parts from the drone or rebuild it.


I'm not sure how it can tell exactly when I'm over or near magnetic interference but nearly every time it makes sense and it "knows".
That's what a compass or magnetic sensor does - that's its job.

Labroides Posted at 10-26 23:47
According to your compass knowledge expertise, disabling all compass calibration checks on all your DJI drones in Any area of the world would be ok?
If the compass is calibrated, it's calibrated for everywhere because compass calibration has nothing to do with your geographic location.
It would be cool if a DJI engineer could come here and tell us Why it has to be calibrated.

So basically "calibrate" is the wrong selected word then or using "calibrate" as part of the UI compass area makes it incorrect?  Either that, you are missing something, or both.  They should just say press here and get ready to spin your drone or you won't take-off.  The bingo probably is.. calibrate means for something else that isn't the compass.

https://phantompilots.com/thread ... plete-primer.32829/

Hope this helps