DJI Drone Help Forum

Mavic Mini flyaway and lost

Hi,

I recenly lost my new Mavic mini just two days before buying it. I wrote DJI support and they analized the logs and determined that it was caused by the wind.

https://www.phantomhelp.com/LogViewer/6UDT3NLE256J2C55N2UX

I’m SURE that it was not caused by the wind. That day it was just about 11km/h. The previous day, same wind and no issues.

If you look at the log you can see in 7m 37s how the mavic mini flies away without trying to fight with the wind. What do you think? GPS error? compass? IMU?

I’m pretty sure that it was not my fault. How could I prove it?

I saw other cases from other users, and flyaway seems to be common in mavic mini. Any ideas?

Hi Daniel,

Sorry for your loss. I see no sign of a fly away, no errors etc.
The light blue line in my chart is the moving line of your drone without any Pitch (and Roll) input.
It tried to hold position, pitch down 15 degrees but moving approx heading 30.
IMO the only reason is wind, to much for your craft.
RTH the same, no pitch input to bring craft home.
Mayby lowering height, yaw heading towards home and full forward in sport mode could bring craft back home.

cheers
JJB

1 Like

And how is possible?

The day before, same wind conditions, the drone did not move without my RC input.

And how is possible that the first 7 min the flight is super normal, and suddenly the drone flies away more than 300 meters with a small wind? I don’t really see in the logs the drone fighting with the wind, even when it tries to RTH…

It just flew away … and dfter that I lost the signal with the RC and I could not control it. Then it disconnected, and I finally ended losing the drone.

How can a 500$ drone behave like that? That day was not too windy. I saw youtube videos and the drone teorically supports winds quite good, but was not my case. I’m very unhappy with this.

DJI offered me a 15% discount buying a new drone, without RC. Do you know how much is it? I’m not sure if I will buy it again, because I don’t really trust mavi mini right now. My experience was very bad.

I noticed that at the beggining of the flight I receive a “Sensor error” (Error in GPS module. Restart the aircraft(Code: 30049).

When I was flying I didn’t see the message because I was looking to the aircraft, because I was taking off. Then visualizing the log I noticed the messages.

Could it be related to the posterior fly away?

Thanks!

Sometimes on the ground the wind feels less than at 75 meter high.
It flew backwards as it could not hold position, it did pitch down.
All that time you did not gave the correct input to the RC to bring it towards home.

There is ofcourse no textual sign in the log that its fighting against the wind, but as it moves backwards with pitch down, that explains it imo.

DJI says that the NotEnoughPower errors (did you get some kind of a warning about power etc?) are ‘normal’ and are being seen when motors need full power.

In the RTH drone acted Oke, first at this height align to home (took about 8 seconds) , heading home 173 but moving direction approx 040-020.

Mayby craft craft could pitch down more, now about 7 degrees down and 11 to the right.
So possible the low power available caused this.

But in both situations you could do more yourself. In RTH fully fwd will increase fwd speed.

I do not think that the GPS mismatch in the beginning has something to do with this ‘fly away’
cheers
JJB

1 Like

I agree that it looks like the MM just wasn’t going to tilt over enough to overcome the wind. But, I wonder if the motors were being commanded to their fullest capacity. At 490 secs the MM was facing into the wind with a pitch down -13° , roll 0°. But, then RTH caused the MM to rotate towards home and pitch was only down -7° and roll 7°. I’d think that the pitch and roll could have been more.


@Daniel_Penalba_Acito could you retrieve the .DAT from the mobile device so we can look at the motor commanded data. Use these instructions
http://datfile.net/DatCon/retrieveV3DatfromTablet.html

I do believe there is a concensus here that wind was most definately a factor. You were at 77meters in altitude, so the winds are stronger. The .txt log is dated December 15th. If that is the case then see below:

Well, after thinking on this incident a lot, I have several questions:

  • 00:00 - 06:45: Same wind as 07:27, (not too much, just 11km/h or so). The drone is able to deal with the wind perfectly. Just move a few centimeters move because of the wind. But all working as expected. I can control it without problems. Why a perfect control at the beggining and then 300m fly away due to the wind? Makes no sense.
  • 06:45 - 07:10: I press forward in the RC and the drone flies perfectly straight. The wind comes from the left. How can the drone deal a perfect straight line, and then, in 07:27 go away more than 300 meters caused by the wind? Makes no sense. I don’t know the reason, but in 07:27 the done doesn’t fight anymore with the wind, and it goes away. Due to the fly awat, I loose the RC signal.
  • 07:37 - 08:31: The log shows how the drone IS NOT FIGHTING with the wind at all. There is no inclination of any kind. The done just drifts in the wind direction. It was in SPORT mode. It should try to maintain the position. When the drone is not able to fight the wind, as I read in the DJI forums, it displays the Insufficient Power - 30168 message. My drone did not display it. Why?

I think that clarifying this issue can help other users not to happen the same.

@BudWalker thank you very much with this help. Here you can find the requested DAT file:

I really appreciate you help me with this. I feel like I’m alone with this. DJI says that it was caused by the wind, @JJB and @Fly_Dawg also believe that. I’m pretty sure that the drone did not behaved as expected. Basically because the beggining of the flight was perfectly normal and then suddently occured the dissaster. The previous day, similar winds, and a perfect flight with no issues. And really believe me that that day it was not too windy.

So I appreciate a lot you guays to help me to find an answer. I would like to have an explanation because right now my appreciation of Mavi Mini, is that it is not worth buying a 500$ done that any time it can fly away due a little bit of wind.

In my post I stated that it’s likely the MM just couldn’t overcome the winds. After looking at the .DAT it’s even more clear that the MM was blown away, It didn’t fly away.

Looking at the motor commanded data it can be seen that either or both of the back two motors were being commanded at 100% during many parts of the flight. When that happens the MM has reached it’s maximum airspeed. If the wind speed exceeds that maximum air speed the MM will be blown away.

Here is the motor commanded for the right back (red trace) and left back(blue trace). The value 1920 indicates 100%.

Regarding the first bullet in the interval 00:00 - 06:45 the back motors reached 100% several times. It may have seemed that the winds were handled perfectly. But, excessive winds may have been hard to notice because they were short. Also the MM was being maneuvered about, not hovering or flying straight.

Regarding the second bullet. The right back was 100% for some of this interval. The MM was being flown with the wind at it’s left back quadrant. It just looked like there was no wind effect.

Finally, bullet number three. The MM was inclined at ~15°. Don’t know why you thought it wasn’t inclined.

In addition to the previous analysis by @JJB and @BudWalker Notice the climbs below. First from 62Meters to 70 Meters, then again to 75 Meters. Once you reached the 75Meter point your altitude began to fluctuate, at times as much as 3 Meters. That to me indicates a strong wind and/or updraft/downdraft.
A few seconds later the NotEnoughForce Flag went true. Also notice that there were several instances during the flight where it was also true. Again indicating that there was an issue with wind.

So, what is the maximum wind speed the Mavic Mini can support without blowing away?

Over 8 m/s will blow it away for sure. I would be very conservative with that number however.

Sorry, don’t know the answer to that. But, it’s clear the max air speed was reached since one or more of the motors was being commanded at 100%

I had the exact issue. All was “good” until I hit the RTH. DJI said it was high winds and I have no reason to doubt them. This drone is very light and the more and more I read the wind is it’s worst enemy (or maybe our worst enemy). I just with the DJI refresh allowed for a replacement since it does appear to be an operator error no different than smashing it into a wall. Sorry for your loss. I feel your pain. My mini was “gone with the wind” and " frankly, DJI didn’t give a damn". :wink:

Hi lawjr, sorry for your loss. But don`t blaim DJI…

If MM users fly their mini in wind situations outside the MM limits, than its a pilot ‘error’.
I have seen many flightlogs where users lost their MM beacuse of thinking that RTH will always bring their craft back to home. Waiting and waiting while craft is drifting away. Most of the time no action like push fully forward in RTH (increase speed) or cancel RTH and max fwd in Sport mode (even more speed).

cheers
JJB

Why RTH does not apply full power?

1 Like

I get it. The frustrating part is I was able to control the drone until I hit RTH. Then even when I cancelled it kept going the other way. Others with way more experience than me had the same issue, so I do understand it was operator error. HoweverI believe there is room for improvement on how RTH works.

Cheers, LAWJR

Good question, guess for drones with obstacle avoidance its nesseccary to give the craft time/distance to stop after sensing an obstacle.
MM had no OA…
Mayby also for less power drain so craft can fly longer distance.

@JJB in my case flying in the city caused my loss. Normal flight around 8 minutes. Then some wind. The wind caused a drift and the drift caused loosing the signal with the rc. Rth was unable to get the drone to home. Drone lost.

Between buildings you don’t feel the wind as strong as it is at 50 or 60 m high.

My lesson learnt 1: MM is not a toy. Learn how to use it and be careful.
My lesson learnt 2: MM is not good enough with wind IMHO.

Just IMO. RTH was designed more with the “fail safe” action in mind. Specifically a low battery scenario, as opposed to lost signal. The aircraft will merely “cruise” at low speed to conserve remaining battery power. To seperate the scenario’s would be cost prohibitive.