Drone disconnected - assume blown away?

[Meta4]

I had been watching a lot of videos about controlling the drone and doing a lot of trial runs to avoid this so feel extremely incompetent at this point in time. I sort of hope it isnt wind again but am guessing that is what happened.

There are some important points that would help to avoid incidents like this in future.
The Mini is a low-speed drone and is poorly equipped to come home against significant winds.
The wind up high is always going to be stronger than what you are feeling down on the ground.
When your Mini loses signal and is trying to come home in RTH, its top speed (in still air) is only 8 metres/sec (18 mph).
Pushing against a 4 m/s wind (9mph) will halve the RTH speed.

In your flight, the Mini was 138 metres up and only making 1.5-2 m/s coming home, between gusts.
During gusts the Mini was being blown backwards at 2-2.5 m/s.
If you fly off downwind into the distance and have trouble coming home, the battle is already lost.
You have to prevent getting into that losing situation and avoid flying off downwind, particularly flying at higher altitudes.
Flying lower will usually put the drone where the wind is not as strong.
Fly into the wind going out.
It might be slow, but the return will be easy.
Doing it the opposite way is asking for trouble.

 

[Deleted member 114292]

There are some important points that would help to avoid incidents like this in future.
The Mini is a low-speed drone and is poorly equipped to come home against significant winds.
The wind up high is always going to be stronger than what you are feeling down on the ground.
When your Mini loses signal and is trying to come home in RTH, its top speed (in still air) is only 8 metres/sec (18 mph).
Pushing against a 4 m/s wind (9mph) will halve the RTH speed.

In your flight, the Mini was 138 metres up and only making 1.5-2 m/s coming home, between gusts.
During gusts the Mini was being blown backwards at 2-2.5 m/s.
If you fly off downwind into the distance and have trouble coming home, the battle is already lost.
You have to prevent getting into that losing situation and avoid flying off downwind, particularly flying at higher altitudes.
Flying lower will usually put the drone where the wind is not as strong.
Fly into the wind going out.
It might be slow, but the return will be easy.
Doing it the opposite way is asking for trouble.

Your advice is good even though it wasn’t a mini.

 

[Meta4]

Your advice is good even though it wasn’t a mini.

My mistake ..
The principles are the same but the other models have a little more speed.
But that's no help if they are put where the wind is too strong for them.

 

[sar104]

The analysis by sar104 is really impressive!!

Thanks for the compliment. The universal applicability of basic mathematics and physics to almost any problem is what impresses me.

 

[acrossthenight]

My mistake ..
The principles are the same but the other models have a little more speed.
But that's no help if they are put where the wind is too strong for them.

Thanks for the feedback. Is there some video guide etc which explains wind and signal issues in more detail. A lot of members here seem to understand them well but I don’t and it’s not for want of trying

 

[acrossthenight]

There's an outside chance that this one might be found; on the plus side, the wind was pretty steady while on the minus side, the descent just before the end of the log makes the extrapolation less confident.

View attachment 96498

View attachment 96499

Extrapolating course and speed from the end of the log to autoland start, and then adding the descent to terrain that is 100 meters lower than the takeoff point (hence the -100) on the height scale, gives the following estimated landing area, with error estimation yielding the green zone:

View attachment 96500

View attachment 96501

Thanks for this. We had a pretty long looK around this area but no dice. I’m curious to know how you can work this out incorporating the wind speed so accurately - totally trust your math - just I look at it and am surprised it gone blown this far away. Do you need to assume a certain constant in the wind speed for the time where it is not producing data?
Appreciate your support

 

[sar104]

Thanks for this. We had a pretty long looK around this area but no dice. I’m curious to know how you can work this out incorporating the wind speed so accurately - totally trust your math - just I look at it and am surprised it gone blown this far away. Do you need to assume a certain constant in the wind speed for the time where it is not producing data?
Appreciate your support

Yes - this assumes that the wind profile remains constant. Without that assumption there is no way to predict the future motion of the aircraft. In this case the wind field looked fairly steady, which increases confidence in the calculation. But if that changed then there is no way to incorporate it into the estimate.

 

[acrossthenight]

Yes - this assumes that the wind profile remains constant. Without that assumption there is no way to predict the future motion of the aircraft. In this case the wind field looked fairly steady, which increases confidence in the calculation. But if that changed then there is no way to incorporate it into the estimate.

Ok thanks. What do you think is a realistic margin of error eg how big of a radius from the likely touch down point would you recommend to try searching? Thanks again

 

[sar104]

Ok thanks. What do you think is a realistic margin of error eg how big of a radius from the likely touch down point would you recommend to try searching? Thanks again

That's the green zone that I posted previously in post #14. I can't guarantee that it is in that area, but if the wind didn't change then it's the highest probability.