Mavic Mini Blown away

[BJMSG06]

Hey!

Let me start off by saying it was a bonehead move for me to be flying today because of heavy wind gusts and also taking off on a less than 100% battery.

When I took off, it wasn't long before the Mavic Mini started drifting away from the home point. I tried to fly it back to no avail, it kept on drifting.

I guess overall what i really want to know is where it ended up. The last reading had it at about 200+ feet. I'm not sure if it started landing at that point or continued to drift away.

I have uploaded the .TXT file is there anything else you would need to help track where the drone may have ended up or what went wrong? First time with this issue. Thanks

 

[JohnLietzke]

Here is a link to your data. Data Link

The only thing I see in the Log is the a battery voltage variation, which appears to be statically insignificant. The last reported height was at 282.8ft. So these logs may be useless to find the last location.

I also had an issue to day where the drones location was not rendering correctly and the video was delayed by at least a minute with full bars. The MA2 was responsive to stick controls but impossible to use the video for visual guidance and the map was throwing up Home Point location errors.
Video on screen inconsistent with drone location.

 

[Meta4]

Let me start off by saying it was a bonehead move for me to be flying today because of heavy wind gusts and also taking off on a less than 100% battery.
When I took off, it wasn't long before the Mavic Mini started drifting away from the home point. I tried to fly it back to no avail, it kept on drifting.
I guess overall what i really want to know is where it ended up. The last reading had it at about 200+ feet. I'm not sure if it started landing at that point or continued to drift away.
I have uploaded the .TXT file is there anything else you would need to help track where the drone may have ended up or what went wrong? First time with this issue. Thanks

There were two fatal problems that caused the loss of your Mini.
1. You showed no awareness of the wind issue or how to deal with it.
2. Your Mini was still running very old firmware Version 1.0.244 which was flaky.
Early on many Minis were lost because their Minis would not maintain proper pitch angle to fly at full speed.
Version 1.0.5 fixed this.

For most of your flight, your Mini's pitch angle was around -10° even in Sport Mode and the speed was not proper Sport Mode speed.
For only a couple of short periods during the flight the pitch angle was what it should be and the Mini made headway against the wind.
There's a good example at 4:54, but it only lasted 6 seconds.

At the end of the flight the battery was being burnt at approx 1% each 12 seconds.
On losing signal, it will have gone back to 300 ft and attempted to RTH.
It will have been blown backwards at approximately 5 mph for another 2.5 minutes before descending due to critically low battery.

It's not possible to give a precise location for where it came down but a rough estimate puts it 100-1700 ft further downwind.

 

[Meta4]

I also had an issue to day where the drones location was not rendering correctly and the video was delayed by at least a minute with full bars. The MA2 was responsive to stick controls but impossible to use the video for visual guidance and the map was throwing up Home Point location errors.

Your issue is unrelated.
If your drone has a clear unobstructed skyview, GPS would normally be providing accurate location data.
If you want assistance understanding what caused your incident, start a new thread and post flight data.

 

[BJMSG06]

There were two fatal problems that caused the loss of your Mini.
1. You showed no awareness of the wind issue or how to deal with it.
2. Your Mini was still running very old firmware Version 1.0.244 which was flaky.
Early on many Minis were lost because their Minis would not maintain proper pitch angle to fly at full speed.
Version 1.0.5 fixed this.

For most of your flight, your Mini's pitch angle was around -10° even in Sport Mode and the speed was not proper Sport Mode speed.
For only a couple of short periods during the flight the pitch angle was what it should be and the Mini made headway against the wind.
There's a good example at 4:54, but it only lasted 6 seconds.

At the end of the flight the battery was being burnt at approx 1% each 12 seconds.
On losing signal, it will have gone back to 300 ft and attempted to RTH.
It will have been blown backwards at approximately 5 mph for another 2.5 minutes before descending due to critically low battery.

It's not possible to give a precise location for where it came down but a rough estimate puts it 100-1700 ft further downwind.

Thank you for that comprehensive analysis. I appreciate it. Lots of lessons learned. So more than likely, at the end of the flight it probably landed somewhere correct? As opposed to just falling out of the sky?

 

[Prismatic]

Thank you for that comprehensive analysis. I appreciate it. Lots of lessons learned. So more than likely, at the end of the flight it probably landed somewhere correct? As opposed to just falling out of the sky?

At the risk of stepping on @Meta4's toes, yes indeed, at the end it almost certainly made a controlled descent and landing, as opposed to falling like a stone. Estimating where it might have landed is a matter for wizards of higher rank than I. ?‍

 

[Camino Ken]

At the risk of stepping on @Meta4's toes, yes indeed, at the end it made a controlled landing, as opposed to falling like a stone. Where, exactly is a matter for wizards of higher rank than I.?‍

Further risking his toes, it could have hit an above ground obstacle (I.e. Tree) and then then tumble uncontrollably to the ground, somewhat similar to a stone.

 

[JohnLietzke]

At the risk of stepping on @Meta4's toes, yes indeed, at the end it made a controlled landing, as opposed to falling like a stone. Estimating where it might of landed is a matter for wizards of higher rank than I. ?‍

Given it had 20% battery at the time it could have flown quite a ways coupled with the wind.

 

[Deleted member 103366]

So more than likely, at the end of the flight it probably landed somewhere correct? As opposed to just falling out of the sky?

It will certainly have descended in a controlled manner but whether it came down in trees etc. or on rooves or over suitable ground is entirely a question of geography.
Given the area it was being blown into I think the chances of a controlled landing are slim and suspect the final few feet may have been a tumble etc.

Whilst it has been pointed out that errors were made I should like to mention that to fight wind the normal suggestions are descend ( the wind is generally slower at lower levels) and switch to sports mode for greater speeds wrt the air.


This also begs the question, when descending due to a low battery does the mini retain the ability to reject the landing site?
If so it presumably hovers, if so and assuming it isn't blown over a suitable landing site, will it remain airborne until the battery is so exhausted that the motors actually stop and it falls the last few ft or will it reach a final threshold where landing is triggered "come hell or high water"?

 

[Terry777]

Hey!

Let me start off by saying it was a bonehead move for me to be flying today because of heavy wind gusts and also taking off on a less than 100% battery.

When I took off, it wasn't long before the Mavic Mini started drifting away from the home point. I tried to fly it back to no avail, it kept on drifting.

I guess overall what i really want to know is where it ended up. The last reading had it at about 200+ feet. I'm not sure if it started landing at that point or continued to drift away.

I have uploaded the .TXT file is there anything else you would need to help track where the drone may have ended up or what went wrong? First time with this issue. Thanks

Sad for ya buddy! I hope you find it... ?

 

[Deleted member 103366]

I hope you find it... ?

Is the neighbourhood the sort of area where if it came down on someone's property the land owners first port of call is going to be their lawyer?

 

[Prismatic]

<*snip*>... This also begs the question, when descending due to a low battery does the mini retain the ability to reject the landing site?
If so it presumably hovers, if so and assuming it isn't blown over a suitable landing site, will it remain airborne until the battery is so exhausted that the motors actually stop and it falls the last few ft or will it reach a final threshold where landing is triggered "come hell or high water"?

I believe in most DJI drones, there is a "hell or high water" landing when the batteries can barely still sustain stable flight. It's a deal you can't refuse, and it happens willy-nilly. Forest or field, expressway or sand dune, ocean or bog, the drone ultimately attempts to land wherever it is.

Blind landing at a random location is inherently dodgy, but we've seen plenty of recoveries from similar incidents, with help from the resident wizards here.

 

[JohnLietzke]

Here are my thoughts on the direction it travel and the distance before being forced to land. I may have under estimated the distance as it burned battery when flying in a non linear manner before you lost connection.

Also check the last point which it had connection. It could have been set to force landing on lost connection and just set down right there.

Your sticks were in neutral position and therefore the trajectory of the craft should not change as it was already facing the Home Point. I used the last position and drew a straight line to Home Point then backed it up halfway.

If it were me, I would move down that blue line. Also, check the ParkView House Apartments because it may have run into on of them on RTH if it lost altitude from 280 ft. I counted the floors at 16 on Google Earth so it is more than likely around it is only 200 ft. Also if RTH was 400 ft it would have consumed battery elevating.

Looking over the flight data again I don't think you would have had enough battery to get back at 20% and it may have initiated a force landing in the water. You were cutting awfully close on battery. Remember somewhere around 10% battery level it begins a force landing which can not be canceled.

What part of NYC do you live in?

 

[boblui]

My estimation is as follows. Autolanding should have started when the battery level hit 5%. Then the drone would start descending. The battery level should reach 0% before the drone reached the ground but it should still be able to fly for around one minute before the battery actually shut down.



The drone may have landed somewhere around here :

 

[JohnLietzke]

My estimation is as follows. Autolanding should have started when the battery level hit 5%. Then the drone would start descending but the battery should be fully depleted on it's way down.

View attachment 116433

The drone may have landed somewhere around here :

View attachment 116434

boblui​

I assumed that direction arrow on the flight log correspond to the the direction of the aircraft. The last position recored had the aircraft pointing almost inline with the Home Point location. Did I miss something in the raw log that was not represented on the scrollable map?

 

[boblui]

boblui​

I assumed that direction arrow on the flight log correspond to the the direction of the aircraft.

That is correct. The fact that the craft was pointing towards the home point does not mean it would fly towards that direction because of the wind. As a matter of fact, just before the disconnection it was flying backward and away from the home point with no stick input . Is that your question ?

 

[JohnLietzke]

Yes. I was only looking at the final markers direction and not factoring in the wind. Also I consider the Auto Return to Home on signal loss direction.

I have the Air 2 so wind is not as big of factor due to size, speed and power.

From my understanding the Mini is so lite that it has a lot of problems in the wind. I figured it might make some headway or be able to slightly over come the wind. As he was in sport mode with a speed of almost 30 mph; I thought it would at least progress back to the Home Point against the 21 mph headwind gusts.

I am just trying to get more interpreting logs, for when the inevitable happen, hence the question.

 

[Meta4]

From my understanding the Mini is so lite that it has a lot of problems in the wind. I figured it might make some headway or be able to slightly over come the wind. As he was in sport mode with a speed of almost 30 mph; I thought it would at least progress back to the Home Point against the 21 mph headwind gusts.

Although it was in Sport Mode, his Mini was only pitching forward 10° most of the time when it should have been pitching 20°-30°, so it couldn't achieve proper Sport Mode speed and deal with the wind.

 

[Barry4]

I would like to share something with all my brother & sister drone pilots. Four weeks ago my Mavic Mini got stuck in a tall tree about 60-70 feet off the ground. Just to high for a ladder
and I did not want to hire a tree service to get it down. So $399.00 later I just bought another Mini. However, I did put my name and cell number on that Mini and today I got the call. It’s been very windy yesterday and today and someone out for a walk found it and called me. That Mini was out in wind, rain & cold for almost 30 days and it’s working just fine. So put your name and number on your drone and you just never know. Hmmmm, I guess I’m asking fir to much for that drone I lost in the ocean during the summer. Oh, well.

 

[slup]

With a drift speed in the end of the log of approx 2-4m/s the search area will be fairly long stretched. When the log ends you still had 11% battery left until low battery autoland which interpolated gives approx 120sec of further drift at present height. We also need to count in the big ground level difference comparing to HP, starting just where the first calculated low battery autoland distance is. At HP the ASL is 69m but further away in the drift direction it is ASL15. This means that the height above ground differs from 86m to 140m ... which of course regulate how long the Mini can drift during the landing. The drift direction was fairly constant during the earlier flight ... came to a conclusion that a difference in tilt direction of 5 degrees can be enough ... that gives the 2 different drift direction. In this we also have another unknown parameter ... how behaved the wind closer to ground, but further away above the lowland ... did the wind follow the ground or became the ground downhill in lee.

And as pointed out in earlier posts, the Mini couldn't maintain a pitch according to spec ... this could have developed to a uncommanded descent much earlier ...

The closest touch down distance is somewhat the same as @boblui calculated ... but due to the big ground level difference it could have continued to drift. Have marked all 4 corner with their GPS positions ... but as you see, the area is rather long and full of taller objects. If you're going to carry out a search I would start from the closest side. But it will be like finding a needle in the haystack unfortunately.



In this pic the difference in ground height is visible ...