Flying a drone was pretty awesome . .too bad it was such a short-lived experience.

I lost my drone immediately  after takeoff as it crashed against a tree roughly 150 feet high up.

This was probably a noob mistake as it was only  my 3d flight and I took off in an area surrounded by trees . . .  however .. .
I couldn't help noticing the drone starting to drift off to the side ON ITS OWN immediately after reaching the altitude I wanted it to be at.
I tried to stop the aircraft using controller input to no avail (or so it seemed to me as everything happened very fast)

Surely I pushed it by deciding to fly in such a dangerous area but part of me would like to think there was also something wonky at play (c'mon! I just lifted off straight up. . that's it!)

At this point I just want to know what really happened and have some closure. Was it all my fault? Did the bird go slighty insane? Was it both?

I appeal to the DJI forum for help.
What tools do I have at my disposal (if any) to peer into the craft's black box in an attempt to figure out what went wrong?
I heard the drone creates flight log and such.
What are the procedures to peer into those?
Any help is greatly appreciated.
Thanks so much in advance.



So sad . . I haven't even had the chance to explore all of the itelligent flight modes

Mavic air has a problems with drifting you can upload your flight logs thru dji assistant 2.

You should takeoff from open space without trees around. It’s easy to have problem when close with trees for beginner. Even takeoff successful you may have problem when landing by passing the trees.

Most important thing is ensure on GPS with 11 or more satellites locked. Check your home point recorded correctly before takeoff. Most unstable problem caused by weak GPS which can be caused by tree cover. Or not waiting to lock enough satellites.

When turn on the drone you should put it on flat surface immediately after power on. Don’t hold it on hand or turn upside down. It need to be in stable place to initial the compass and IMU.

Dirty Bird Posted at 2018-8-12 19:44
Have to agree with the previous two comments.  New pilot, taking off surrounded by trees where GPS-lock can easily be lost.  Bird drops into ATTI mode, no longer holds position, wind causes it to drift, CRASH!

Post your flight log & one of the Log Gurus will delve into your crash & figure out what went wrong.

Thanks for all the replies and comments.
Any steps on how to get to those logs or any web page you can point me to?
Cheers

I took off once with my Mavic Aid before home point had been recorded. It was all over the place. For a brief second I thought something was wrong with it, then I heard 'home point recorded' and then it was rock solid. It then made sense.
Until there is a GPS lock, the bird will be in Atti mode which will drift with the wind and the only thing maintaining altitude is the barometer.
I learned from that and will never take off until I hear 'her' say home point has been recorded.

Trees tend to eat drones at a healthy rate. Especially when you're starting out. Hopefully you have the Care Refresh and can get your drone repaired.

Hi Bossinator, we're so sorry to read the accident. Just to verify, did you contact DJI GO 4 during the last flight? If yes, you may check the feature "Find My Drone" to see whether the drone can be found or retrieved. If still no luck, please kindly contact support@dji.com and report the accident. For the unit under the warranty period, we'll arrange data analysis to check the exact status and offer you a proper solution.

I am very sorry for your crash! Were you able to recover your Mavic Air? You may upload your flightrecord (it is stored in a DJI subfolder on your mobile device) to this site and share the link with us: http://www.phantomhelp.com/LogViewer/Upload/
You description of the incident sounds as if you had taken off in ATTI mode, but the flightrecord will show that.

I'm really sorry for your crash. Find the file ending with .txt in DJI/dji.go.4/FlightRecord map of your mobile device, using file manager, if it is Android or iTunes if it is IOS

Some time credit card have an extended warranty for those things. You could check it out.

DJI Susan Posted at 2018-8-13 00:00
Hi Bossinator, we're so sorry to read the accident. Just to verify, did you contact DJI GO 4 during the last flight? If yes, you may check the feature "Find My Drone" to see whether the drone can be found or retrieved. If still no luck, please kindly contact support@dji.com and report the accident. For the unit under the warranty period, we'll arrange data analysis to check the exact status and offer you a proper solution.

Hi Susan.
Thanks. Will contact  DJI support right away.

Everyone else . . thanks to those of you who gave me instruction on how to unpack the flight Record.
Memory DID serve me well. I indeed took off in GPS mode albeit with a fluctuating number of satellites (record shows a minimum of six to a maximum of 9)

Here is the flight record for those who asked:
http://www.phantomhelp.com/LogViewer/4QLC0JTXZ2E1Z9DOKZ2G/
I looked at both the numbers in Xcel and the flight path in Google earth and I can see the moment  the aircraft started drifting toward the tree however this stuff is new to me so maybe somebody can get a better understanding out of all this data.

I was hoping the record would also show controller inputs as I had the impression the drone kept drifting despite my attempts at correcting its trajectory. Unfortunately the record only shows positional values but doesn't offer insights about user inputs being logged as those values are being generated. (am I wrong here? Please let me know)

If you come up with something do let me know.
Thanks in advance.

Bossinator Posted at 2018-8-13 20:57
Hi Susan.
Thanks. Will contact  DJI support right away.

I was hoping the record would also show controller inputs as I had the impression the drone kept drifting despite my attempts at correcting its trajectory.

If you want to see controller inputs, you need to go to link you posted and download the CSV file.  

For now, avoid the Verbose CSV file.  It has way way more information and is harder to look through.

HedgeTrimmer Posted at 2018-8-13 21:15
I was hoping the record would also show controller inputs as I had the impression the drone kept drifting despite my attempts at correcting its trajectory.

If you want to see controller inputs, you need to go to link you posted and download the CSV file.  

Hi HedgeTrimmer.
I have the CSV open in Xcel
Are the user inputs the "pitch", "roll", "Yaw" columns or are those simply positional values of the aircraft? . . in short. . . which ones are the columns showing positional data Vs pilot's input?
Thanks in advance

Hey Boss,  You had a few satellites locked, I would say that due to the treed location, not a good lock.
Therefore GPS Health was poor and the Aircraft remained in atti mode.
It seemed to be responding well to stick inputs.
I would say that due to the uncharacteristic Atti flight behaviour, than that your normally used to, when it drifted slightly, in those last couple of seconds panic set in and it crashed.
Sorry for your loss.
I would suggest in the future, choosing a more open area to fly.

Sorry for the crash, DJI will surely help u. Do take necessary precaution next time.

Simmo1 Posted at 2018-8-13 21:27
Hey Boss,  You had a few satellites locked, I would say that due to the treed location, not a good lock.
Therefore GPS Health was poor and the Aircraft remained in atti mode.
It seemed to be responding well to stick inputs.

Hi Simmo1.
Don't have to tell me twice! Lesson learned (the hard way)
Despite (sadly) not being able to re-join the drone fun due to $$$ restrictions I do like what you did here on the debugging side. I was trying to do something similar in Xcel. Is that what you did or did you use some other application?

Bossinator Posted at 2018-8-13 21:22
Hi HedgeTrimmer.
I have the CSV open in Xcel
Are the user inputs the "pitch", "roll", "Yaw" columns or are those simply positional values of the aircraft? . . in short. . . which ones are the columns showing positional data Vs pilot's input?

The input from RC to drone would be:
            

RcAileron	RcElevator	RcGyro	RcRudder	RcThrottle
1024	1024	1288	1024	1024

     

Bossinator Posted at 2018-8-13 21:22
Hi HedgeTrimmer.
I have the CSV open in Xcel
Are the user inputs the "pitch", "roll", "Yaw" columns or are those simply positional values of the aircraft? . . in short. . . which ones are the columns showing positional data Vs pilot's input?

A good primer on FlightLog files RC / Drone meaning of Aileron, Elevator, Rudder,..
Aileron, Elevator and Rudder

My summary:
RcAileron - Tilt left side down (Roll to left) - decrease left side motors speed & increase right side motors speed - resulting in Sway to left
RcElevator - Tilt Nose down (Pitch to front) - decrease front motors speed & increase rear motors speed - resulting in Surge forward
RcRudder - Rotate Nose left (Yaw to left) - increase/decrease motors speed of cw/ccw turning motors - resulting in spin to left
RcThrottle - Raise entire drone (increase altitude) - increase all four motors speed - resulting in Heave upwards
RcGyro - Offset of nose pointed direction vs. actual direction of moment (needs a better description)

The Rc_____ commands are what is sent to drone's flight control system, what actual happens in regards to change in four motors' RPM's to accomplish command is up to drone.

UPDATED: Had Pitch / Roll swapped for drone.

Bossinator Posted at 2018-8-13 21:38
Hi Simmo1.
Don't have to tell me twice! Lesson learned (the hard way)
Despite (sadly) not being able to re-join the drone fun due to $$$ restrictions I do like what you did here on the debugging side. I was trying to do something similar in Xcel. Is that what you did or did you use some other application?

Not sure what program Simmo1 used for sure.
But a really good program available to Windows users is JJBspark's FRAP.

FRAP - Update 2 Analysis program

Screen Shot from FRAP

Bossinator Posted at 2018-8-13 21:38
Hi Simmo1.
Don't have to tell me twice! Lesson learned (the hard way)
Despite (sadly) not being able to re-join the drone fun due to $$$ restrictions I do like what you did here on the debugging side. I was trying to do something similar in Xcel. Is that what you did or did you use some other application?

Simpler way to remember controls.



* Plus Pitch – Move Forward
* Minus Pitch – Move Backward
* Plus Yaw – Turn Right
* Minus Yaw – Turn Left
* Plus Roll – Move Right
* Minus Roll – Move Left
* Plus Throttle – Stand Taller
* Minus Throttle – Crouch

All the recent crashes I have read on the forum all to be down to the aircraft switching to ATTI mode due to either taking off with low gps or in your case poor location. Sorry for you loss but if you had read the manual you would then have been aware of the risks you were taking.

People need to:
1) Read the manual https://dl.djicdn.com/downloads/ ... 20Manual%20v1.2.pdf
2) Learn to fly in big open fields
3) Maybe learn to fly a drone that does not have GPS http://a.co/3uyWCXH
4) Start in Beginner Mode
I can't believe that people who don't even know what yaw is start trying to fly their $1000 drones without doing that first.



DJI Needs to:
1) Put a manual in the box, not just a quick guide - or at least a bright yellow sticker on the drone with the URL
2) Put another bright yellow sticker indicating what happens in Atti Mode, and encouraging simulator use (could even force user to pass sim test before allowing to fly)
3) Allow  user to manually switch to Atti for practicing loss of GPS4) Create a basic LOS PC simulator that does not rely on the drone to be on.


Having said that, I do sympathize, I know what it feels like to crash your drone (my crash was a combination of Litchi mission, poor planning and a particularly healthy, tall tree), I hope you can recover it!

Yes, all the truth is told above, you've got a hard lesson  to be able to avoid take off without 11-12 sats locked at least, without Home point recorded, without IMU and compas distortion and many, many other important things.
Good luck in future flights

I'm of the opinion that DJI should force some kind of a tutorial with quiz that all new owners MUST PASS before the drone becomes operational.  Granted, this might cut into their revenues as it seems every other newbie destroys their drones within the first couple of days, but it just blow my mind reading these every day where someone rips open the package, tries to fly in very constrained areas, quickly crashes, and are left wondering what went wrong?  They simply don't have a clue.

RcGyro (RC Gyro or Gyro) gets convoluted coming from early days (human smarts only) RC helicopters.
RcGyro is merely a Label assigned to data Column of CSV, so perhaps another term / meaning.

Anyone have a better / accurate description of what is meant by RcGyro in relation to FlightLog and command data info as used by DJI?  

For your drone to fly correctly and smoothly IMU gyro stabilization and flight controller tech is essential , that’s how we get smooth video even in high winds.

inbuilt gyro stabilization giving Your camera or sensor close to vibration free movement. This allows us to capture perfect aerial film and photos.

OneDoesNotSimply Posted at 2018-8-14 03:58
People need to:
1) Read the manual https://dl.djicdn.com/downloads/ ... 20Manual%20v1.2.pdf
2) Learn to fly in big open fields

I agree.
As a first time drone buyer I was so worried about flying within the law that I spent more time learning about the ins and outs of it rather than the mechanics and the physics of the flight itself.
The quick guide that came with my Mavic Air (not a full manual) also gave me a false sense of security that led me to rely too much on the tech driving the bird. (aahh  . .was I so wrong!)
Yes, DJI should put a full manual in the box. . I would have read it.
There is nothing sadder as looking at my fly more combo pack without an actual bird in it.

And BTW thanks to all of you who took the time explain what columns pilot's input corresponds to in the flight log. Also for the apps recommendations to decipher the data. That's very useful.

Bossinator Posted at 2018-8-14 11:41
I agree.
As a first time drone buyer I was so worried about flying within the law that I spent more time learning about the ins and outs of it rather than the mechanics and the physics of the flight itself.
The quick guide that came with my Mavic Air (not a full manual) also gave me a false sense of security that led me to rely too much on the tech driving the bird. (aahh  . .was I so wrong!)

The full manual is in your app, you can download it and print it.

DJI makes you accustomed to flying in NERF mode, most pilots get stunned that they can't actually fly a drone. If you don't have GOOD sat-sig and you haven't practice flying in Atti, it's a recipe for disaster. DJI please make ATTI available in the flight simulator, so pilots can train. Or by a racing drone.

It makes good sense. Understanding now how things work I wouldn't mind being able to put the drone on ATTI for training purposes (low altitude, big, wide open spaces or simulation)

LordoftheFlies Posted at 2018-8-14 12:01
DJI makes you accustomed to flying in NERF mode, most pilots get stunned that they can't actually fly a drone.  If you don't have GOOD sat-sig and you haven't practice flying in Atti, it's a recipe for disaster. DJI please make ATTI available in the flight simulator, so pilots can train. Or by a racing drone.

Nothing at you.
But it is telling how some lecture about Pilot error, lack of Pilot experience, and that Pilots must be in full control in case something goes wrong - while skipping over Pilots can not practice ATTI mode without either hacking drone or buying another drone that flies in ATTI mode.

Bossinator Posted at 2018-8-14 12:55
It makes good sense. Understanding now how things work I wouldn't mind being able to put the drone on ATTI for training purposes (low altitude, big, wide open spaces or simulation)

Mavic Pro or Mavic Air never had Atti mode and are not likely to ever have Atti mode. Practicing Atti mode with your $1000 drone is always a bit of a risk, even most phantom and inspire users will advise buying a cheap Syma or similar to practice Atti . Both phantom and inspire operate the same as Mavics if aircraft goes to Atti mode, it’s automatic and this system has proven much better for dji drones than the old system where you had to switch to Atti and once you done this you never knew if you had regained gps mode, so this often caused more problems.
Having an Atti switch will only give you one real option and that is to practice Atti mode, but would you be willing to first try it with something that has set you back so much of your hard earned money.

Bossinator Posted at 2018-8-14 12:55
It makes good sense. Understanding now how things work I wouldn't mind being able to put the drone on ATTI for training purposes (low altitude, big, wide open spaces or simulation)

At least with Mavic Pro, it would not even have to be done in big, wide open spaces - were it an option.

You can buy:
1) clear plastic bubble to protect camera and gimbal.
2) prop cages that fully enclose props, that comes with special (low performance?) props

Then pick a large room, minus any fragiles, to start practicing in.

hallmark007 Posted at 2018-8-14 13:12
Mavic Pro or Mavic Air never had Atti mode and are not likely to ever have Atti mode. Practicing Atti mode with your $1000 drone is always a bit of a risk, even most phantom and inspire users will advise buying a cheap Syma or similar to practice Atti . Both phantom and inspire operate the same as Mavics if aircraft goes to Atti mode, it’s automatic and this system has proven much better for dji drones than the old system where you had to switch to Atti and once you done this you never knew if you had regained gps mode, so this often caused more problems.
Having an Atti switch will only give you one real option and that is to practice Atti mode, but would you be willing to first try it with something that has set you back so much of your hard earned money.

Yes, I can see your point.
So if the idea was to learn how to fly unaided by GPS signals (which is not my purpose here), ideally one would purchase a very cheap drone for that purpose alone while sticking to a Mavic-type drone for aerial photography and such.

Bossinator Posted at 2018-8-14 13:27
Yes, I can see your point.
So if the idea was to learn how to fly unaided by GPS signals (which is not my purpose here), ideally one would purchase a very cheap drone for that purpose alone while sticking to a Mavic-type drone for aerial photography and such.

If you can master one of those cheap drones, then Atti mode will be a piece of cake, and they are great fun and very durable. Chances of going into Atti mode are in fact very rare in dji drones, particularly if you fly in good environments and have a good preflight checklist.

Boss, you've gotten some good advice from your fellow pilots here.  Sorry you had to learn the hard way.  Believe me, I understand.  Glad you have a good attitude about it.  Hopefully you'll be able to get back in the air soon.

Were you able to recover the aircraft, or is it still in the tree?

Bossinator Posted at 2018-8-14 13:27
Yes, I can see your point.
So if the idea was to learn how to fly unaided by GPS signals (which is not my purpose here), ideally one would purchase a very cheap drone for that purpose alone while sticking to a Mavic-type drone for aerial photography and such.

Your might be interested in a Thread I started today.  Out of my concerns of drone suffering a problem that kicks it into ATTI mode, and having to take full human control.

? Cheapest drone to practice ATTI mode with ?

3-D Posted at 2018-8-14 17:43
Boss, you've gotten some good advice from your fellow pilots here.  Sorry you had to learn the hard way.  Believe me, I understand.  Glad you have a good attitude about it.  Hopefully you'll be able to get back in the air soon.

Were you able to recover the aircraft, or is it still in the tree?

Sadly it is still in the trees, a good 150 feet up or more and got doused in heavy rains the day following the crash just to add insult to injury.