Mavic Air briefly fell out of the sky, then steadied itself.

[MavicCF]

Sorry about that, do you think uploading via Google Drive may provide better speeds?


Yes exactly that drop. Its odd as I had buttery smooth POV/signal during the whole drop, with no error messages. I'm not sure if dropbox is the best format to upload the DAT file, here's a google drive link:

18-05-16-06-33-14_FLY003.DAT

Thank you for having a look, I'm a little lost when it comes to troubleshooting this issue.



Its the standard black colour.

No your fine, my internet just sucks sometimes...

 

[sar104]

The DAT file motor data are interesting:



The FC increased the motor speeds to near maximum, but the aircraft still descended. The winds were calculated to be fairly moderate - around 10 mph out of the north - but what were the atmospheric conditions like? Is there any chance that it was caught in downdrafts or vertical windshear?

 

[Jegs]

The DAT file motor data are interesting:

View attachment 38155

The FC increased the motor speeds to near maximum, but the aircraft still descended. The winds were calculated to be fairly moderate - around 10 mph out of the north - but what were the atmospheric conditions like? Is there any chance that it was caught in downdrafts or vertical windshear?

Interesting indeed! I've flown this same route a couple of times over the past few weeks under similar wind/weather conditions without experiencing any potential windshear. The wind was almost non-existing at ground level on the day if that helps at all.

In your experience would the DAT file results be consistent with a bird attack? Given the motors appeared to be functioning properly surely it could have only been an issue with wind/birds?

 

[sar104]

Interesting indeed! I've flown this same route a couple of times over the past few weeks under similar wind/weather conditions without experiencing any potential windshear. The wind was almost non-existing at ground level on the day if that helps at all.

In your experience would the DAT file results be consistent with a bird attack? Given the motors appeared to be functioning properly surely it could have only been an issue with wind/birds?

I've not seen log data for a bird attack, but I would expect to see evidence of motor obstruction and impact-type changes to attitude. Neither of those is in evidence here. I've never seen anything quite like this at all, so I'm really just speculating at this point.

 

[jaybird66]

Seems a downdraft might be a plausible reason since it seems a bird strike would have involved at least one motor, but I'm new to this.

 

[rfc]

The FC increased the motor speeds to near maximum, but the aircraft still descended.

Doesn't this imply some sudden (and intermittent) internal control disparity? Is there something within the system that might do something analogous to what the IMU/Compass thing does to heading? Like a sudden barometer/GPS mismatch? What does the A/C rely on for altitude control at these altitudes?

 

[sar104]

Doesn't this imply some sudden (and intermittent) internal control disparity? Is there something within the system that might do something analogous to what the IMU/Compass thing does to heading? Like a sudden barometer/GPS mismatch? What does the A/C rely on for altitude control at these altitudes?

I'm not following your reasoning. It appears to me that the FC was fully aware that it was descending, and requested increased motor speeds to counteract the descent. All four motors appropriately spooled up in response, but the aircraft telemetry and the video show that it continued to descend.

So what do we know?

1. The aircraft was descending;
2. Motor speed was near maximum;
3. There is no indication of prop or motor obstruction;
4. The props were undamaged;
5. Pitch and roll were not large enough (< 30°) to reduce the vertical component of thrust below the weight of the aircraft.

Possible explanations:

1. The aircraft was being dragged down by external load;
2. Lift was reduced by local vertical (downward) air motion;
3. The motor data are incorrect.

If this were a Phantom then (1) might be explained by a bird grabbing the landing gear (from behind since nothing appears in the video) without affecting the props, but on a Mavic there is nothing to grab, and any attack from above would show up as motor obstruction. (3) seems unlikely since the data look good for the rest of the flight and the motor speed and motor command data agree. Improbable that it seems, that really only seems to leave (2) - hence my previous question. I have no other credible hypothesis to offer.

 

[jpbluzharp]

Hi All,

First time poster here! - I'm hoping anyone can make sense of an issue I've had with my Mavic Air.

Has anyone had any experiences of their Mavic dropping out of the sky briefly before regaining control?

I was flying roughly a mile away over the countryside (unobstructed) and the Air seemed to lose control, drop around 100 feet in 3-4 seconds, then regain control.

I flew the drone back as soon as possible but can't think of any reason it would drop like a stone and then steady itself. I'm incredibly nervous to take it back out now.

Any ideas why this happened/is happening?

Flight Log of drop:

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Footage of drop:

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Attached the Flight Log (TXT).

I'd appreciate any help or insight at all!

Cheers

Try keeping line of sight like the FAA rules suggest. You’ll know what happened next time.

 

[Stimmy]

Try keeping line of sight like the FAA rules suggest. You’ll know what happened next time.

He did. Just not VLOS, if you wanna get all technical Mr police man.

 

[Chips]

It's a weird occurrence. I had my Spark motors stop while it was in landing mode and it fell from 80 metres. Unfortunately for me, the motors did not restart all the way down and it hit my awning and then bounced up (the awning is a moderately soft plastic). When it bounced up, I saw the propellers looked like they were spinning under power again and tried the sticks and got back control. I brought it down normally and it seemed undamaged, surprisingly.

Experts have looked at the log data and can't see anything odd. Anyway, I have lost my trust in the drone even if they repair it as I feel I was very very lucky this time. Next time, it might come down on a busy highway. Lose a drone is one thing, cause an accident and I could get arrested. So I've got a Mavic Pro.

In your case, I tend to support the theory that it was hit by a bird (or a UFO). It looks that way and from some friends who have had their drones attacked, the action seems similar, like a bump.

 

[RayOZ]

Any chance a helicopter flew overhead? A very remote possibility?

 

[sar104]

Any chance a helicopter flew overhead? A very remote possibility?

That would do it.

 

[ed956]

Try keeping line of sight like the FAA rules suggest. You’ll know what happened next time.

There’s always one!

 

[Ex nihil]

Swooshdave, do you have an opinion about colour and its attractiveness to birds? It's relevant to scuba diving and sharks, maybe birds?

 

[Bigbird48]

Currently I'm trying to set a world record for "longest time taken to download a 5MB file" I think I'm up to about 20 minutes and going strong!

It took me 10 hrs 20 min to upload a 3.9 gig file to you tube

 

[Aerial West]

i feel like he might have noticed a helicopter.

 

[sar104]

i feel like he might have noticed a helicopter.

Most likely - yes - although he was over a mile away at the time, so depends on line of sight, ambient noise etc.

 

[NRRTRAINS]

could it have been an air pocket , only because you did not lose complete loss of your drone and it did recover and you were able to get it back home . do you know what the KP index was at the time of your flight . you were over a mile away that also may have had some thing to do with the drop .

 

[MavicCF]

It took me 10 hrs 20 min to upload a 3.9 gig file to you tube

Heck, anything in the GB range would take me months

 

[RayOZ]

could it have been an air pocket , only because you did not lose complete loss of your drone and it did recover and you were able to get it back home . do you know what the KP index was at the time of your flight . you were over a mile away that also may have had some thing to do with the drop .

KP index affects electronics. It wouldn't have affected the drone that way. The motor rev up, but it was still falling.