Please select Into the mobile phone version | Continue to access the computer ver.
Mavic 3 went out of control
328 23 7-20 01:41
Uploading and Loding Picture ...(0/1)
o(^-^)o
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

Hi everyone,
Unfortunately my Mavic 3 crashed
contacted DJI and based on their diagnosis, it was the pilot's fault.
I really find this hard to accept but i do understand that their decision is based on the data that is available.

Here's what happened, I flew the drone not far from me and noticed there was an issue/error showing on my phone screen, my first response was land the drone to double check and fix it. The problem was the drone was not following any of my commands. In short, I couldn't even land it and I couldn't even fly it near me.
Suddenly, it flew straight ahead and my initial response or command i inputted was to THROTTLE up to avoid the obstacle, which is a big tree, but it also didn't follow that command.
From my perspective it went out of control and flew in a straight line till it crashed, I couldn't even stop it. Fortunately, nobody got hurt.
The aircraft crashed and it was badly broken. I'd like to ask a second opinion about my case and anyone's expertise.

this is my flight log https://www.phantomhelp.com/logviewer/9WLTWQYJU8KNVFI9G571

I hope I provided enough information for analysis.

Thank you in advance!
7-20 01:41
Use props
Labroides
Captain
Flight distance : 9991457 ft
Australia
Offline

I hope I provided enough information for analysis.
Yes ... that's fine for analysis.
Did DJI give you more details or just tell you it was your fault and leave it at that?

Looking at your brief flight, it looks like you are a new flyer?
You powered up the drone and launched 3.5 seconds later.
You didn't wait for the drone to get GPS reception which would have provided horizontal position holding and "brakes".

The VPS sensors, which would also help with position holding at low altitudes were not working so it looks like the flight was carried out in darkness?
You flew with full stick, not realising that without position holding, the drone would not stop when you went hands off, and would keep drifting like driving on ice.
WIth gentle moves on the stick, the drone would have been fully controllable.
If there were no obstacles close, the flight woould have been safe.

But with no position holding or brakes, making full stick moves and obstacles nearby, this flight was doomed from the start.



7-20 02:07
Use props
Sean-bumble-bee
Captain
Flight distance : 15515 ft
  • >>>
United Kingdom
Offline

Where was the flight flown (location)  and in what enviroment, indoors/outdoor? If outdoors a BIG question is ''why no satellites?'', were you surrounded by trees or buildings?
Did you notice the location depicted in the PH map?



7-20 02:10
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

Labroides Posted at 7-20 02:07
I hope I provided enough information for analysis.
Yes ... that's fine for analysis.
Did DJI give you more details or just tell you it was your fault and leave it at that?

Here is what DJI told me,
"FLY0031-01
Date of incident: 2022-07-07
Incident GPS coordinates: N/A, Unit was flying with no GPS signal; coordinates were not recorded.

1.    Unit was in ATTI mode due to low GPS signal.
2.    At t=127s, relative height=9.5m, the unit recorded an impact.
3.    User commanded ROLL right, PITCH forward, YAW right, and THROTTLE up prior to impact.
4.    Unit was drifting prior to impact due to poor flight environment.
5.    Unit was flying with no GPS the vision position sensor cannot perform properly. Please refer to manual on factors which can affect vision position sensor performance.

According to the analysis, the incident was not caused by product malfunction. Please fly with caution."


Not a new flyer, but I understand that based on what you said, it was a rookie mistake on my part.

No, the flight was not carried out in darkness, I was outdoor with a pretty safe distance from the trees that my drone hit. I don't think I flew with full stick. I flew the drone and like what you said didn't wait for the GPS reception, but i didn't go full stick and i didn't fly it far and I let the drone hover. That's when I noticed the notification issue on my phone screen, after I noticed it, I tried to land it and fly it near me but I already lost control. Next thing I know, the drone was flying straight to the trees where i gave my drone a pretty safe distance and wasn't even trying to fly it next to those trees. I guess the drone flying to the trees seems like I did a full stick, but I didn't. wasn't even touching the sticks when it flew in a straight line.

I do understand your point that the moment the drone didn't get enough time to get the GPS reception was already bad enough. But still, I seriously think the drone should not behave like that.
7-20 02:26
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

Sean-bumble-bee Posted at 7-20 02:10
Where was the flight flown (location)  and in what enviroment, indoors/outdoor? If outdoors a BIG question is ''why no satellites?'', were you surrounded by trees or buildings?
Did you notice the location depicted in the PH map?

I was on a beach, outdoor. i was not surrounded by buildings and trees. There were trees but I am not definitely surrounded. I gave my drone a pretty safe distance from those trees.

No satellites, I didn't give it enough time to get the GPS reception?

I didn't notice it. Please elaborate.
7-20 02:29
Use props
Labroides
Captain
Flight distance : 9991457 ft
Australia
Offline

schann Posted at 7-20 02:26
Here is what DJI told me,
"FLY0031-01
Date of incident: 2022-07-07

DJI's analysis is brief and without explanation, but it's accurate.

but i didn't go full stick
I guess the drone flying to the trees seems like I did a full stick, but  I didn't. wasn't even touching the sticks when it flew in a straight  line.
The data shows almost every joystick input was full stick.
Without brakes, the drone continues at that speed when you centre the sticks.
You can see the joystick inputs but putting your cursor on any line in the table and looking at the two squares in the lower right of the map window,

But still, I seriously think the drone should not behave like that.
The drone had no way to behave differently because that's what happens when you lean on the sticks with no GPS and no brakes.

7-20 02:44
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

I understand.

If the drone wasn’t following the commands I was giving it, will the drone still try to follow those commands?

The full stick input you are seeing was me trying to land it but it wasn’t moving. And then I let go of the sticks. And that when it starts moving, that moment I already knew it was gonna crash cause I wasn’t even touching the sticks any longer except my last input which is throttle up, that was me trying to avoid the trees but it still didn’t respond.
7-20 02:52
Use props
Labroides
Captain
Flight distance : 9991457 ft
Australia
Offline

schann Posted at 7-20 02:52
I understand.

If the drone wasn’t following the commands I was giving it, will the drone still try to follow those commands?

If the drone wasn’t following the commands I was giving it, will the drone still try to follow those commands?
The drone was following the joystick inputs, but because it couldn't stop it would have been disorienting and given you the impression that it wasn't responding.


The full stick input you are seeing was me trying to land it but it wasn’t moving. And then I let go of the sticks. And that when it starts moving, that moment I already knew it was gonna crash cause I wasn’t even touching the sticks any longer except my last input which is throttle up, that was me trying to avoid the trees but it still didn’t respond.
Apart from throttle input, you pushed the right stick full ahead for 9 seconds early in the 30 second flight.
That would have got it up to a high speed.
Late in the flight you pulled the right stick full back for nearly a second and then to fully forward + fully right + full throttle + full right rudder until the crash impact at 31.0 seconds.

7-20 03:13
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

Please bear with me. if we can have 2 perspective, from the data’s perspective, what you are saying, the aircraft was following my inputs? And it was because of my inputs why the aircraft went full straight ahead till it hits the trees?

Because on my perspective, the drone was just hovering given those inputs you have mentioned based on the data, which are my inputs. Those inputs, are the very inputs that I didn’t get any kind of response on my aircraft before it flew on a straight line hitting the trees and crashed.

If I’m gonna put it this way, it would be like this?

My perspective and what I saw that has happened:
Inputs #1(all the inputs you mentioned) > no response&hovering >  Flew in a straight line> throttle up > crashed

&/or

Data’s perspective
Inputs #1 > no response&hovering > Inputs #1 registered > flew in a straight line> throttle up > crashed?
7-20 03:31
Use props
Sean-bumble-bee
Captain
Flight distance : 15515 ft
  • >>>
United Kingdom
Offline

Labroides.
You say "The VPS sensors, which would also help with position holding at low altitudes were not working so it .....",  from where do you get the information that ther sensors were not working? I see a message, "Vision sensor(s) blocked" at 3.8sec but am wondering if there is something else too?

What is the reason the drone did not seemingly descend when commanded to do so during the "Gentle GPS"  phase of the flight.
Is there a reason for the raggedness of the drone's pitch during the "Gentle GPS" phase? Does the log record anywhere whether OA has done something?


Schann is the following 2.    At t=127s, relative height=9.5m, the unit recorded an impact. a copy and paste from the DJI response? If so I am wondering where they get their timestamp from? 9.5m / 31.2ft corresponds to around the 31 sec mark.
M3 atti.png
7-20 03:37
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

Yes, the DJI’s response was a copy paste from my email. I can attach or copy paste the entire email but I think those are the informations needed in this thread.

And for your question about where they get the time stamp from, I don’t know I’m afraid.
7-20 03:39
Use props
Labroides
Captain
Flight distance : 9991457 ft
Australia
Offline

Sean-bumble-bee Posted at 7-20 03:37
Labroides.
You say "The VPS sensors, which would also help with position holding at low altitudes were not working so it .....",  from where do you get the information that ther sensors were not working? I see a message, "Vision sensor(s) blocked" at 3.8sec but am wondering if there is something else too?

You say "The VPS sensors, which would also help with position holding at low altitudes were not working so it .....",  from where do you get the information that ther sensors were not working? I see a message, "Vision sensor(s) blocked" at 3.8sec but am wondering if there is something else too?
The whole flight was conducted with zero sats and in atti mode.
DJI analysis confirms this too.
If VPS had been working, it would have said Opti Mode.

What is the reason the drone did not seemingly descend when commanded to do so during the "Gentle GPS"  phase of the flight.
I don't know ... something you can puzzle about.
But it wasn't why the drone crashed.

Is there a reason for the raggedness of the drone's pitch during the "Gentle GPS" phase? Does the log record anywhere whether OA has done something?
Despite the label, there was no Gentle GPS phase of flight as there was no GPS.
Obstacle avoidance needs brakes and position holding.
It can't work without either GPS or VPS.

7-20 04:00
Use props
Labroides
Captain
Flight distance : 9991457 ft
Australia
Offline

schann Posted at 7-20 03:31
Please bear with me. if we can have 2 perspective, from the data’s perspective, what you are saying, the aircraft was following my inputs? And it was because of my inputs why the aircraft went full straight ahead till it hits the trees?

Because on my perspective, the drone was just hovering given those inputs you have mentioned based on the data, which are my inputs. Those inputs, are the very inputs that I didn’t get any kind of response on my aircraft before it flew on a straight line hitting the trees and crashed.

what you are saying, the aircraft was following my inputs? And it was because of my inputs why the aircraft went full straight ahead till it hits the trees?
That's right.

Because on my perspective, the drone was just hovering given those inputs you have mentioned based on the data, which are my inputs. Those inputs, are the very inputs that I didn’t get any kind of response on my aircraft before it flew on a straight line hitting the trees and crashed.
When I look at what the drone did, it matches your joystick input.
When you pushed the right stick forward, the drone instantly pitched forward to 30°.
You held the stick forward for 9 full seconds, so the drone had to have gone forward at full speed.
It followed your joystick commands.
At 28.4 sec you pulled the right stick full back and the drone pitched backwards at almost 30° to try to stop.
Then you pushed the right stick full forward and full right and the drone pitched forward again at 28° and rolled to the right at 23°.
Those movements would have been reflected in the movement of the drone, but without brakes, it couldn't just stop and reverse direction.

My perspective and what I saw that has happened:
Inputs #1(all the inputs you mentioned) > no response&hovering >  Flew in a straight line> throttle up > crashed
You didn't touch the sticks until 3.6 sec.
At 3.6 sec you pushed left stick up and gave gentle rudder and the drone started to climb and rotate slightly.
At 4.2 sec you pushed right stick full forward and the drone pitched 30° and the drone would have rocketed forward.


7-20 04:26
Use props
Sean-bumble-bee
Captain
Flight distance : 15515 ft
  • >>>
United Kingdom
Offline

I don't know ... something you can puzzle about.
But it wasn't why the drone crashed.

True that it did not cause the crash but, if Schann had been able to bring the drone down and land it, it may not have have been near the object into which it crashed.

Despite the label, there was no Gentle GPS phase of flight as there was no GPS.

I quoted the flight mode so that the area of the chart was obvious, but thanks for the information.

Obstacle avoidance needs brakes and position holding.
It can't work without either GPS or VPS.

Thanks..... but doesn't that make the raggedness of the pitch between 4.16sec and 13.06sec all the more inexplicable?
7-20 05:05
Use props
Tornado12
Second Officer
Flight distance : 356391 ft
United States
Offline

Oh boy. I looked through the flight log. Obvious red flags from the pilot right off the bat. Are you a new pilot? New to drones? You powered up the motors and then was in the air in less than 3 seconds, with errors regarding the gimbal being stuck. Why are you in such a rush? You have zero satellites and are taking off and going straight into ATTI mode. This is a recipe for disaster. Without knowing the surroundings, the wind speed, or any thing else, just going purely on the flight log, I would agree with DJI that this is pilot error. At the time of the crash you are full stick forward  on throttle. To me the most important facts here are:

- You took off way too fast after powering the drone. Motors start and 3 seconds later you are already up in the air. Why are you rushing?
- You had 0 satellites the entire ~32 second flight. For a new pilot, flying in atti mode is a recipe for a crash.
- Because of your rush to get into the air, not only are you flying around with 0 sats but you have ignored a nerror about gimbal being locked. Why was the gimbal locked? Again, why are you rushing so fast that you ignore errors and 0 sats?
- Again, because of your rush get into the air, you are flying with no homepoint being set. If anything happens in flight and you lose connection, the drone has no home point, no positioning, no way to return to you. You are taking a risk.

Couple of questions - What obstacle avoidance mode where you flying in? Why did you take off so rapidly and what was the rush that made you fly with zero satellites, forcing yourself into an atti mode flight? A majority of drone crasshes occur in atti mode, as the drone is flying with no positioning. If you are on a beach with white sand below, the vision positioning system could also be compromised. Its hard to say what occured in those final seconds when you claim the drone began to ignore your inputs, but everything up to that point was really poor decisions. You put yourself in a really bad situation by taking off so rapidly with zero gps satellites. The drone will behave very differently when in Atti mode, and it leads to a lot of crashes like this.

All this said it is possible you had other issues at play. Im curious why the gimbal was locked and throwing an error. You ignored this error though and took off. It seems every crash I look at the pilot is always taking off way too fast. This is yet another case of a pilot rushing take off. I just dont udnerstand why people are flying this way, with a $3,000 drone. You really need to wait for homepoint lock before flying off.
7-20 06:37
Use props
CloudVisual
First Officer
Flight distance : 24718996 ft
  • >>>
United Kingdom
Offline

Tornado12 Posted at 7-20 06:37
Oh boy. I looked through the flight log. Obvious red flags from the pilot right off the bat. Are you a new pilot? New to drones? You powered up the motors and then was in the air in less than 3 seconds, with errors regarding the gimbal being stuck. Why are you in such a rush? You have zero satellites and are taking off and going straight into ATTI mode. This is a recipe for disaster. Without knowing the surroundings, the wind speed, or any thing else, just going purely on the flight log, I would agree with DJI that this is pilot error. At the time of the crash you are full stick forward  on throttle. To me the most important facts here are:

- You took off way too fast after powering the drone. Motors start and 3 seconds later you are already up in the air. Why are you rushing?

3 Seconds..! I didn't know it was even possible to fly this quickly from power up.

The audacity of OP to start a thread thinking the drone was at fault and expect that DJI will agree and we would all give pity.

The thing is, when I see threads like this pop up, it's going to catch my attention because I want to know if there's a bug or issue. 99.9% of the time it's pilot error and it tends to be once the logs have been released and the truth comes out.
7-20 07:03
Use props
JJB*
Captain
Flight distance : 9210935 ft
  • >>>
Netherlands
Offline

schann Posted at 7-20 02:26
Here is what DJI told me,
"FLY0031-01
Date of incident: 2022-07-07

Hi schann,

Had a look at your flight too.

During whole flight no GPS. (as you already know...)
At 2.6s in flight the max height was set by the FlyApp to 5 meter.
At 13.6s the max height was set to 30 meter. [GPS not available + Downward vision availabe ]
This is for DJI to answer as out of range it must be set to 5 (or 3 in the manual)

Direct after take-off the warning "Aircraft in Attitude mode. Unable to hover. Fly with caution"Unfortunatley this message is shown in a split second on the screen....if you had seen this warning ; time to stop the flight immediatley (if you not experienced pilot)
But this warning was incorrect, as after take off the downward sensor was active, thus hover stability thanks to this vision sensor.
So, after takeoff your M3 was flying stable thanks to the downward vision sensor.
Downward vision sensor 'stopped' working bc of out of range ; last height measured 24.6 meter.

After relasing full forward stick at 13s your MR had a speed about 10 m/s.
Out of Vision range and no GPS the speed in the log is not correct, as it need or GPS or XY data from the vision.

M3 at 13s in ATTI mode (no GPS, no DownwardVision), releasing fwd stick should normally bring drone to a stop BUT not without GPS and VISION.
At 26s and further you tried to stop the 'uncontrolled' move, but no succes.

Main reasaon for your crash, not good idea to start a flight without a GPS lock + no HomePoint set.
Check the top right GPS icon FlyApp screencoloured
red = no GPS or not enough sats for GPS lock
amber = GPS lock
white = GPS lock + HP set ; time to fly....

PS

statement from DJI is not correct ofcourse, not correct mildly written.
"Unit was flying with no GPS the vision position sensor cannot perform properly."
Vison and Downward vision sensor functions independent of GPS, whether yes / no receiving satellites.

cheers
JJB




analysis1.png
Mavic3vision.png
analysis2.png
7-20 07:22
Use props
JJB*
Captain
Flight distance : 9210935 ft
  • >>>
Netherlands
Offline

Labroides Posted at 7-20 04:00
You say "The VPS sensors, which would also help with position holding at low altitudes were not working so it .....",  from where do you get the information that ther sensors were not working? I see a message, "Vision sensor(s) blocked" at 3.8sec but am wondering if there is something else too?
The whole flight was conducted with zero sats and in atti mode.
DJI analysis confirms this too.

Hi

OPTI mode is never shown in the FlyApp.

Flying with zero sats and downward vison active : shows N-Mode in flight.....
see this > https://forum.dji.com/forum.php?mod=viewthread&tid=268055
It has the attention of the DJI software engineers.

cheers
JJB


7-20 07:25
Use props
JJB*
Captain
Flight distance : 9210935 ft
  • >>>
Netherlands
Offline

Sean-bumble-bee Posted at 7-20 05:05
I don't know ... something you can puzzle about.
But it wasn't why the drone crashed.
True that it did not cause the crash but, if Schann had been able to bring the drone down and land it, it may not have have been near the object into which it crashed.

Hi

Your question

Obstacle avoidance needs brakes and position holding.
It can't work without either GPS or VPS.

Thanks..... but doesn't that make the raggedness of the pitch between 4.16sec and 13.06sec all the more inexplicable?

Flying with any speed into ATTI and all sticks to zero : pitch and roll angles drone flat angles, but no automatic opposite angles to brake.


cheers
JJB
7-20 07:57
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

CloudVisual Posted at 7-20 07:03
3 Seconds..! I didn't know it was even possible to fly this quickly from power up.

The audacity of OP to start a thread thinking the drone was at fault and expect that DJI will agree and we would all give pity.
I started this thread to have a better answer with explanations. I didn’t ask for your pity. I was asking for a more detailed explanations. And to find out the truth, I’m not afraid of what comes out with my flight log, I can accept it 100%. I would rather have someone tell me everything in truth rather than the response on DJI that I had. I needed to know the truth with a detailed explanations, not only to learn from it but to have peace from the outcome caused by me.

I will own my mistake and will keep learning. I’ll take full responsibility.

Thank you for your time and expertise.
7-20 10:22
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

JJB* Posted at 7-20 07:22
Hi schann,

Had a look at your flight too.
[Image]
Hi JJB,

I understand. I wasn’t satisfied from the DJI’s response on this case. I had to look for more answers.

I checked out the thread you shared too.

Thank you for your time and expertise. Thank you for your very detailed explanations. I am now well aware that it was clearly my fault.

I learned a lot from this experience. I’ll make sure to be a safer flyer from now on. I really do appreciate this.
7-20 10:43
Use props
hallmark007
Captain
Flight distance : 7859656 ft
  • >>>
Ireland
Offline

schann Posted at 7-20 10:43
Hi JJB,

I understand. I wasn’t satisfied from the DJI’s response on this case. I had to look for more answers.

Lots of users make similar mistakes , many are lucky to get away with it, but what you can learn from it will make you a much better flyer. Its a tough way to learn and something nobody likes to see happen to others. Below is a short exercise you can do before every flight it takes a very short time and will prove over time to very helpful to all flyers. Good luck in the future.

1/ Never calibrate Compass unless prompted to. Your compass will always prompt to calibrate if it needs it .

2/ start AC leave until you receive enough gps lock ,

3/ if you get Compass interference turn off AC and move to another location,
without interference.

4/ In bottom left hand corner on your map you will see small red/blue triangle, check to make sure that this triangle is pointing in the same direction (heading) as your AC, this will show good compass on the ground.

Raise AC to height of 8ft
Hover for 20 seconds
Fly forward 2ft
Backward 2ft
Left 2ft
Right 2ft
Up 2ft
Down 2ft
Yaw left
Yaw right
Each time returning to hover position
If you have a good horizontal each time, you will then know you have good GPS good IMU and good Compass, and your ready to fly.

This exercise takes less than 1 minutes and is worthwhile doing before every flight,
7-20 10:59
Use props
CloudVisual
First Officer
Flight distance : 24718996 ft
  • >>>
United Kingdom
Offline

hallmark007 Posted at 7-20 10:59
Lots of users make similar mistakes , many are lucky to get away with it, but what you can learn from it will make you a much better flyer. Its a tough way to learn and something nobody likes to see happen to others. Below is a short exercise you can do before every flight it takes a very short time and will prove over time to very helpful to all flyers. Good luck in the future.

1/ Never calibrate Compass unless prompted to. Your compass will always prompt to calibrate if it needs it .

I would like to say that this is excellent advice, follow this and you're almost certainly guaranteed to not encounter the same issue.

However, in my professional opinion. Simply letting the drone acquire 12+ satellites and have it confirm a home point recorded will also ensure this doesn't happen. OP you rushed things and this is the consequence.

When I learned to sail a yacht, I got taught a phrase; "Slow is Pro". There is nothing worth rushing.
7-20 13:12
Use props
schann
lvl.1
Flight distance : 129770 ft
United States
Offline

CloudVisual Posted at 7-20 13:12
I would like to say that this is excellent advice, follow this and you're almost certainly guaranteed to not encounter the same issue.

However, in my professional opinion. Simply letting the drone acquire 12+ satellites and have it confirm a home point recorded will also ensure this doesn't happen. OP you rushed things and this is the consequence.

Thank you hallmark007 and CloudVisual for these excellent Advices. I’ll take it to heart and to always do it before each flight. I am taking full responsibility and I am owning my mistake. It’s a tough way to learn but it is what it is. What I’ll do next is the most important now.

Thank you for educating me on this. I learned a lot, I’m a big fan of learning. I will keep learning.

I really do appreciate this. Thank you for the time and effort.
Thank you for explaining.

I love that “slow is pro”, I’ll take this with me from now on.
Similar to military, “slow is fast”.


Thank you all and I appreciate all of you for taking the time to look into this. Mahalo!!!
7-20 14:01
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules