Mavic 2 Pro Crash Suddenly in sport mode

[TTP]

One conceivable explanation may be that the front left propeller,
which is missing according to the picture as sebi1996 shows, has loosened thanks to the part holding the propeller blades to the engine, it consists of two halves, the upper and the lower, the lower having three heels which locks the propeller to the engine. This part is subjected to great stress, and is the weakest part, in my experience, forming a propeller pair. Of the at least four different makes available for the M2P, the version that is in the current drone, DJI 8743F, is not exactly the strongest.

When sebi1996 switches to S-Mode, my theory, right or wrong, is that the part one of the parts I'm talking about above breaks down because of the strain, and hence the crash.

The right front propeller is broken probably depends on when the drone hits the ground.

 

[slup]

One conceivable explanation may be that the front left propeller,
which is missing according to the picture as sebi1996 shows, has loosened thanks to the part holding the propeller blades to the engine, it consists of two halves, the upper and the lower, the lower having three heels which locks the propeller to the engine. This part is subjected to great stress, and is the weakest part, in my experience, forming a propeller pair. Of the at least four different makes available for the M2P, the version that is in the current drone, DJI 8743F, is not exactly the strongest.

When sebi1996 switches to S-Mode, my theory, right or wrong, is that the part one of the parts I'm talking about above breaks down because of the strain, and hence the crash.

The right front propeller is broken probably depends on when the drone hits the ground.

So how can this theory explain that the right back engine were commanded to 93% but only put out 0rpm's in the moment it went down? See post #11

 

[sar104]

One conceivable explanation may be that the front left propeller,
which is missing according to the picture as sebi1996 shows, has loosened thanks to the part holding the propeller blades to the engine, it consists of two halves, the upper and the lower, the lower having three heels which locks the propeller to the engine. This part is subjected to great stress, and is the weakest part, in my experience, forming a propeller pair. Of the at least four different makes available for the M2P, the version that is in the current drone, DJI 8743F, is not exactly the strongest.

When sebi1996 switches to S-Mode, my theory, right or wrong, is that the part one of the parts I'm talking about above breaks down because of the strain, and hence the crash.

The right front propeller is broken probably depends on when the drone hits the ground.

There was no front left prop problem - it was motor failure - back right.

 

[TTP]

View attachment 91751

View attachment 91751

sebi196, did you find the missing propeller from the left front, at the drone's impact site?

 

[sebi1996]

Update:
Good news, DJI will repair my Mavic for free!
But it was more damaged then I expected and the drone looked like.
8743_Press-down Quick-release Propeller CCW defect. 8743_Press-down Quick-release Propeller CW defect. Front Aircraft Arm Module defect. Front Arm Module defect. Mavic 2 Pro Gimbal Axis Arm Module defect. Upper Cover Module defect. Rear Arm Module defect. Rear Arm Module defect

Thanks guys for your support!
Greetings from south Germany

 

[kubeon]

Hi guys, found this topic as today I had similiar failure - my Mavic 2 fell from the sky in sport mode not hitting anything. What software did you use to look into propellers speed? I doesn't seem to be airrdata.

 

[slup]

...What software did you use to look into propellers speed?...

The mobile device DAT log + CsvView

Read more about logs here --> Mavic Flight Log Retrieval and Analysis Guide
Download program here --> CsvView Downloads

 

[kubeon]

Found it. thank You. I try to figure out the direct couse and my idea is the bird strike (less likely) or falling apart of propeller that jammed the motor. In fact I was pushing it in sport mode. Am I right?

 

[Meta4]

Found it. thank You. I try to figure out the direct couse and my idea is the bird strike (less likely) or falling apart of propeller that jammed the motor. In fact I was pushing it in sport mode. Am I right?View attachment 140114

If you post your .txt file that will go a long way to answering your questions.

 

[kubeon]

Attached both .dat and .txt files.

 

[Meta4]

Attached both .dat and .txt files.

Towards the end of the flight you were descending while flying forwards/left at full speed in Sport Mode.
At 535.4 sec you released the joysticks
0.4 seconds later the drone is knocked hard and rolls to the right completely upside down.
It was a little over 200 feet higher than the launch point at the time and no obvious obstacles appear in that area.
It starts losing height and tumbling, and hits the ground with power still connected and full signal.
This looks like a collision with something rather than a simple lost or broken propeller incident.

 

[slup]

...the drone is knocked hard and rolls to the right...This looks like a collision with something...

I'm not fully convinced about that ... it's an odd one this.

Looking at the craft accelerations in the X(forward/backwards), Y(right/left) & Z(up/down) axis it may look like something hit the craft approx at 534sec from the left front side & below ...

(Click on the charts below to make them larger)


... which also is consistent with a right roll & up pitch.



But if this acceleration would have been initiated by an outside coming force the motors would have tried to counteract the movement ... but that isn't quite what we see.

This is the RPM & the FC command for the rear right motor ... if something would have affected the diagonal opposite side (lifting the front left) that motor would have been highly commanded & the motor would have reacted with an rapid increase in the RPM. But instead we see a somewhat inconsistent behavior from the FC & a constant low RPM from the motor.



The front left motor that would have taken a blow from below would have counteracted by lowering the RPM ... through a decrease in the FC command. And that ... is what's seen.



So ... the reactions from the flight controller on the front left vs. the rear right doesn't add up when it comes to counteract a outside coming force that makes the craft diagonally roll right & pitch up.

OK ... let's check the other 2 motors also.

The front right ... hmm, again a similar strange behavior as the rear right. The motor is commanded nearly to max but only average RPM's is produced.



The rear left then ... the FC command adds up with how the RPM changes.



In the end we see a craft that rolls to the right & pitches up & by the acceleration data it looks like either the front left is lifted up or the rear right is pushed down. We also see that both the right motors doesn't follow the FC commands ... the rear right worse than the front.

The flight controllers inability to get proper reactions through the commands show up in the DAT log even stream ...



The amp draw also reveals that something is going on for both the RIGHT motors ... first the rear right peaks (it's when the RPM nearly goes to a stand still) ... then the front RIGHT follows with a amp peak shortly after.



All this aren't conclusive ... but something is affecting the right side motors, they don't follow the FC commands, the RPM's from them aren't what to expect if something hit the craft from below in the front left side ... and the amp draw peaks for both motors even though they don't produce RPM's.

If the reason for this isn't blocked motors ... on both the right ones ... perhaps the below can give a clue.

The ESC temps are consistently higher on the right side than on the left side during most of the flight ...