What do I do when my Mavic Mini does a fly-away?

[Yorkshire_Pud]

Just a follow up reply. I tested the emergency motor cut out and it actually takes a few seconds to activate which is a relief.

Regarding 1 and a "safe" altitude)
in many cases it will ascend to RTH height but it will only ascend to the height you set for RTH. If you are setting that height too high then lower it. But note, when I last tried that when the drone was actually in an RTH the change would not 'take'.
I aim to clear obstacles in an RTH flight path by around 10m. Any greater height is excessive IMO. I change RTH height to suit the location.
Do not trigger RTH as a 'guaranteed cure' for being blown away (see * below). Descending and switching to sports mode is your best bet.

Regarding 2) there is no trigger distance. If the drone's maximum airspeed in any mode is less than the wind speed it can not hold position and that is irrespective of its distance from home.

* In RTH mode the mode has its own nominal speed limit but this can occasionally be increased by giving forward stick. I do not remember if it applies if the drone was, before the RTH, in any mode other than in sports mode but it does apply if the drone was in sports mode when the RTH was activated.

 

[mavic_minis_fly_away]

I cannot set RTH below 15m and 15m is still too high for strong winds. In the situation today, the wind was strong above 2m and I was flying at about 5m so was totally stuffed when it RTHed. Thankfully I was composed and aborted the RTH.

I have a flight log where the drone is pushed backwards (it faces towards me into the wind). It has an OSD pitch averaging about -20. When it stops going backwards the pitch remains at an average of -10 for 7 seconds until I fly it back towards me (when the pitch goes to an average of -20 again). This tells me that the drone was remaining in place but not using all its power to get back to me. Full power would be a pitch of about -20.

 

[Yorkshire_Pud]

In respect of a 15m minimum RTH height paragraph 1 is as it should be. I am unsure of what you are trying to suggest or imply in paragraph 2 but the behaviour you see in the log is also as it should be.

The elevator and aileron, in effect, command desired ground speed.
A drone will do its best to comply with the commands you are giving it but it has limits set by the programming.
It uses ONLY the necessary/available air-speed/pitch to follow your commands as best it can, if the wind speed drops then 1 of two things will happen,
a) if it was not struggling prior to the wind speed drop and was able to reach your commanded ground speed then it will reduce its pitch to comply with the commanded ground speed, or
b) if it was struggling and or losing ground then it will, in terms of ground speed, accelerate to do its best to comply with your commanded ground speed, this may also include reducing its pitch.

Regarding
"I tested the emergency motor cut out and it actually takes a few seconds"
the attached is an excerpt from a log where I did a test CSC.
You will see that I start moving the joystick towards the CSC position at 8.8 seconds, the CSC is reached at 9.1 seconds. The motors stop, ending the log, at 10.8 seconds.
As I remember the two accidental CSC threads that I have seen, both had delays around 1.7 seconds, as did my experiment.

 

[mavic_minis_fly_away]

In respect of a 15m minimum RTH height paragraph 1 is as it should be. I am unsure of what you are trying to suggest or imply in paragraph 2 but the behaviour you see in the log is also as it should be.

The elevator and aileron, in effect, command desired ground speed.
A drone will do its best to comply with the commands you are giving it but it has limits set by the programming.
It uses ONLY the necessary/available air-speed/pitch to follow your commands as best it can, if the wind speed drops then 1 of two things will happen,
a) if it was not struggling prior to the wind speed drop and was able to reach your commanded ground speed then it will reduce its pitch to comply with the commanded ground speed, or
b) if it was struggling and or losing ground then it will, in terms of ground speed, accelerate to do its best to comply with your commanded ground speed, this may also include reducing its pitc

In 2) I am saying that the drone appears to stop and not return despite an apparent drop in wind. Ultimately the internal drone mechanics are a black box but it's good to know how it behaves.

I wish I could set a lower RTH altitude than 15m (i.e. out of the wind) because commanding the drone to lower than 15m takes many seconds while the drone blows away.

 

[Yorkshire_Pud]

I think that either your drone is misbehaving or you are misunderstanding how it operates. There is one other possibility but I do not know if it relates to the Mavic Mini with current firmware and App, my Mavic mini has not been updated and I generally use pre 1.2 Apps with it and I think it DOES NOT apply to my Mavic Minis..

Let's deal with the latter first, with some of the Fly-app-using drones changes were made or introduced so that certain stick actions can cancel an RTH at various phases of the RTH. I do not know, or can not remember, if that is applicable to the Mavic Mini. You should check this and see if it applicable to your drone with whatever firmware/app-ware is being run. If it is applicable then check whether you are issuing those stick commands and cancelling the RTH.
Otherwise. ------------------

If the drone is in RTH, its 'unassisted' maximum ground speed is 8m/s. In windless conditions that corresponds to a certain pitch angle. I do not know what that angle is nor do I know for certain whether or not the drone can, in an unassisted RTH, exceed that angle but I suspect it can.
However there will be a certain tilt angle that the drone will not exceed in unassisted RTH, that tilt angle corresponds to a certain air speed, note air speed NOT ground speed and I do not know what that airspeed is.

So, let's say that that air speed is 12m/s and the drone is RTHing into a headwind.
At any wind speed up to and including 4m/s the drone would be able to fly at a ground-speed of 8m/s towards home.
Ground-speed is what you see reported on the display of the app.
If the wind speed exceeds 4m/s then the drone's ground-speed will be reduced, to (12 - windspeed)m/s, I have seen this many's a time.
Extending this idea, if the wind speed was 12m/s the drone can not make headway, with respect to the ground, and appears to hover. If the windspeed is greater than 12m/s then the drone will be blown away at (wind speed -12)m/s.

If the wind was equal to or faster than 12m/s but drops to below 12m/s then the drone will start to make headway towards home at the speed calculated above.

If you are not somehow cancelling the RTH and your drone does not RTH when the windspeed drops below whatever that unassisted maximum air-speed is, then there is something wrong with your drone.

Note I refer to unassisted RTH etc. because, as described in post #41 the maximum RTH air speed can increased by given the drone forward-stick/elevator, I would call doing that "assisting" the drone and the relevant RTH an "assisted RTH".