Prop or bird hit?

[kmstan]

Trying to understand this data. Did the drone have a critical failure with a prop, or was this an attack by a bird or ??

Per the video, the drone went out and up to an altitude of about 80 feet, hovered, I switched to Sport mode, and there was some sort of critical event.

In the trimmed video I can't tell if the left front prop failed, or if a bird's talon has the drone. It enters a death spiral and on the right side, it appears that an arm retracted or something?

Or maybe hit by another drone?

I lost the Mavic into salt water. I know it's toast, but am still going to try to recover it tomorrow...

 

[zeusfl]

Your flying uploaded to Airdata.

 

[Yorkshire_Pud]

What happened around 105 seconds into the flight? There were two maximum power warnings when the drone was low and close.

 

[Meta4]

In the trimmed video I can't tell if the left front prop failed, or if a bird's talon has the drone. It enters a death spiral and on the right side, it appears that an arm retracted or something?

The incident started at about 4:14.3 with the drone starting to rotate clockwise despite no rudder input and rolled slightly to the right.
In half a second, it had rotated 90°.
At 4:14.9 it rolled heavily to the right and pitched steeply forward, the spinning increased and the drone tumbled and spun downwards.

The way the incident started gently suggests that it's more likely to be a prop coming off than a sudden collision impact.

Or maybe hit by another drone?

Was there another drone close enough to be a concern?

 

[zeusfl]

The fact that is giving max speed warnings of spinning too fast give you probably cause of propellers out of pitch or too flat.

I agree with @Meta4 probably a propeller went off. However, the battery drop suddenly increasing the amps may indicate something else. Maybe a motor locked? Strike?

 

[slup]

Think this is a pretty straight forward prop failure in the Right Rear ...

Already early, before you flew away from the HP you got a "max power load reached" error ... that indicate that some or one of the motors were approaching max rpm's.

You were here when the error came up at 105sec after take off ... yellow bar is your MA2. My guess is that something holding one prop blade... or the blade itself had a crack letting the blade to twist making the angle of attack shallower ... meaning that the prop intermittent was producing less thrust & the motor was forced to rev up to compensate.



Later in flight, now over the water you flew in normal mode full elevator stick ... but there at 253sec you change to Sport mode on the fly, not letting go of the stick. The craft starts to pitch down in order to increase the heading speed ... but only a second later, at 254 the MA2 quickly pitches up, roll to the right & twists clock wise. All these movements indicate a fatal loss of thrust from the Right Rear side ... together with the early "max power load reached" error my guess is that it here the prop blade breaks off completely.

(Click on the chart to make it larger ... chart marker placed where the incident starts)

 

[FLDave]

The first battery voltage concern is at takeoff while just a few feet up--that according to the AirData notifications. It seems those notifications should have been investigated before flying 2 more minutes over the water where some catastrophe occurred.

 

[maggior]

The first battery voltage concern is at takeoff while just a few feet up--that according to the AirData notifications. It seems those notifications should have been investigated before flying 2 more minutes over the water where some catastrophe occurred.

Assuming that the messages seen in the log starting at 1:45 are displayed in DJI Fly, the lesson is to not continue the mission but bring it right back down.

Thankfully the catastrophic failure occurred over water and not over a location that could have caused damage or harm.

It's a good idea to inspect the props as part of the pre flight inspection. I check mine as I unfold them to ensure that each one is properly attached and that there is no physical damage to them. I hold onto the motor and attempt to turn the prop attachment on the motor to ensure they are locked in well. I also inspect the hinges that the blades are attached to.

 

[kmstan]

Thanks everyone for reviewing.

There were no other drones in the area and after carefully reviewing the frames from the video, it didn’t look like a bird was involved.

I did not notice a warning or strange behavior early in the flight. That observational mistake probably cost me the drone.

Expensive lesson. Glad I only fly UAV drones.

Thank you again for your analysis.

 

[Prismatic]

See, this kind of thread is why I keep coming back to this forum.

From the OP’s unfortunate mishap and the ensuing analysis, I came to realize that I’ve been somewhat too cavalier in my preflight inspection.

My condolences to the OP, and thanks to all.

 

[kmstan]

See, this kind of thread is why I keep coming back to this forum.

From the OP’s unfortunate mishap and the ensuing analysis, I came to realize that I’ve been somewhat too cavalier in my preflight inspection.

My condolences to the OP, and thanks to all.

We have to learn from our mistakes or we're just dummies Glad my $1,000 mishap might prevent another.

-Kevin