Wind warning + RTH

[Starsky1970s]

I was wondering what would happen if this warning came up and the RC lost connection due to a weak signal at this point during a strong wind warning? in normal circumstances the MM would enter a fail safe and return to home until connection was made. Anyone experienced these at the same time?

 

[BadWolf1]

1. The drone can be told in advance, for failsafe RTH, Hover or Land.
2. If there is a loss of signal which exceeds 11 seconds it will follow the failsafe option.
3. The warning says there have at least been gusts of wind which may mean at the pitch used in RTH the drone can not make forward progress.
4. If you have signal and cannot over come the the wind, you can (a) Engage sport mode to fly at a steeper pitch (b) Descend because wind is stronger higher up (c) land where you are preserving some battery to help you find the drone.
5. If you lose signal the drone will go into failsafe (normally RTH). If the RTH height is higher than the present height it will ascend, then it will aim for home. We get what is usually called a "blow away" if the drone can't overcome the wind. When there is no signal you end up trying to work out when the battery will trigger a forced landing, and where the wind will have blown it by that time.

 

[Starsky1970s]

My setup in failsafe is RTH, the warning does say "unable to RTH automatically". So that would result in step 5 in my case if I was to experience both at the same time?

 

[PhantomFandom]

My setup in failsafe is RTH, the warning does say "unable to RTH automatically". So that would result in step 5 in my case if I was to experience both at the same time?

Wind condition does not alter the failsafe RTH process. It would still do the same thing, and in this case it would most likely not be able to make it home, and instead be blown away.

Best solution is to not get into that situation. Situational awareness and pre-flight planning would keep you from flying into such conditions...especially with a MM which is by any measure underpowered.

 

[Gkinghrn]

'RTH cant return to home automatically' - it can IF you have it in sports mode .... IanFromLondon done a youtube video on just that but with a MA2 - not sure how different a mini would be ...

 

[PhantomFandom]

'RTH cant return to home automatically' - it can IF you have it in sports mode .... IanFromLondon done a youtube video on just that but with a MA2 - not sure how different a mini would be ...

Couple of issues with that....

• The MM does not have much power so even in sports mode, it is very easy to have a stronger headwind than the MM can handle.
• In Sports Mode you would need to fly it home yourself, which doesn't help you in cases where you lose signal.
• Unless something has changed recently, a RTH always uses a set speed/power setting (something akin to best cruise velocity in an airplane). So it does not matter what mode the MM was in before initiating RTH. it will always come home with the same power setting. *This of course would not be the case if it has changed recently in the firmware with the MM.

 

[vindibona1]

Wind condition does not alter the failsafe RTH process. It would still do the same thing, and in this case it would most likely not be able to make it home, and instead be blown away.

Best solution is to not get into that situation. Situational awareness and pre-flight planning would keep you from flying into such conditions...especially with a MM which is by any measure underpowered.

What would you say is the highest wind level one could fly the MM in, assuming good battery strength, to stay out of trouble? I always consult UAV forecast, before flying, but not sure what would be considered a safe condition for the MM to make sure it could fight a headwind on RTH.

The one thing that scares me with RTH is that you have to make sure that it's more than high enough to clear any obstacles, but being cautious in that regard could put it up higher and experience even stronger winds.

 

[Meta4]

I always consult UAV forecast, before flying, but not sure what would be considered a safe condition for the MM to make sure it could fight a headwind on RTH.

If you have to fight a headwind for your return flight, you might have already lost the battle.
You have to think about that before you launch the drone and avoid getting into a situation your drone won't be able to come home from.

 

[Gkinghrn]

Couple of issues with that....

• The MM does not have much power so even in sports mode, it is very easy to have a stronger headwind than the MM can handle.
• In Sports Mode you would need to fly it home yourself, which doesn't help you in cases where you lose signal.
• Unless something has changed recently, a RTH always uses a set speed/power setting (something akin to best cruise velocity in an airplane). So it does not matter what mode the MM was in before initiating RTH. it will always come home with the same power setting. *This of course would not be the case if it has changed recently in the firmware with the MM.

Suggest you find and watch the MA2 video I mentioned then decide if that is relevant or not before just dismissing it ... was only trying to help ...

 

[PhantomFandom]

Suggest you find and watch the MA2 video I mentioned then decide if that is relevant or not before just dismissing it ... was only trying to help ...

I was not dismissing it. I was just trying to give accurate information so that others don't get a false sense of security in thinking that they can just pop it into Sports Mode and get more success in RTH.

It would also be easier to watch the video had you provided a link to it.

If the video you are referring to is this one... Mavic Air 2: RTH Strong Wind Warning - What it Actually Means & What You Should Do then I would say that everything I mentioned is totally accurate, and nothing has changed:

• The video is misleading at best. Nowhere is there any proof that Sport Mode will help getting the drone home safely in RTH.
• From 4:40 to 4:57 he says twice that the way to get back is to put it into Sports Mode and DESCEND. That means flying it home manually as I said before. Sport Mode will not help if you decide to do RTH.
• From 5:30 to 5:50 he again specifically states that in a strong wind RTH will not necessarily get it back as it is struggling to fight a strong wind.
• Also the MA2 is a very different beast than the MM. The MM would fail to get home with winds that the MA2 could handle.

So might I suggest that you watch the video again and pay close attention to the specifics of how to get home in strong wind? Note that the correct way to do it is to get in Sports Mode, do not engage RTH, descend to a lower altitude with less wind, and fly it home manually.

 

[Deleted member 103366]

'RTH cant return to home automatically' - it can IF you have it in sports mode .... IanFromLondon done a youtube video on just that but with a MA2 - not sure how different a mini would be ...

Gkinghrn wouldn't it be simpler for you to post a link to the video? At least that way people can be certian they are watching the correct video.

 

[vindibona1]

If you have to fight a headwind for your return flight, you might have already lost the battle.
You have to think about that before you launch the drone and avoid getting into a situation your drone won't be able to come home from.

I'm sure it was an oversight, but consulting UAV first was to do exactly that. In that response I had asked what the maximum wind speed that a Mini should fly in but did not get a response, so I must assume that nobody has that figure in memory. Here's what I found when Googling that:

" Under warranty, the Mavic Mini can handle wind speeds of up to 28.4 km/h. " That would translate 17.5mph.
So, do the FCC and CE models have the same POWER rating to fight wind? Of is the power differential I keep hearing about transmission only?

And while what I found doesn't include the terms "under warranty" I did find on another website " The Mavic Air 2 can withstand wind speeds up to 23 mph. "
[or 37 km/h]
Other Drone website wind information

I've already experienced run-aways, though not due to wind with a less expensive non-DJI drone and it wasn't fun (declared defective and refund demanded). When I look at the UAV forecast app if gusts are more than 12mph I'm just not gonna fly. I don't have huge open areas to fly in and if I had to do an emergency landing with the drone away, it might be difficult to recover even if I could be guided to it.

 

[Dave Maine]

Power refers only to transmit power. It has nothing to do with flight. Flight airspeed is determined by the tip angle used by the drone to move in the desired direction.

 

[BokiFly]

View attachment 106933
I was wondering what would happen if this warning came up and the RC lost connection due to a weak signal at this point during a strong wind warning? in normal circumstances the MM would enter a fail safe and return to home until connection was made. Anyone experienced these at the same time?

Happened to me. I think it was the first time that I had that warning, and few seconds after that I lost signal with the drone (because of the distance). I panicked a bit, but I did the only thing that I could - I waited. After some time connection was established and I saw that drone is returning. Apparently wind was not that strong and Mini successfully executed RTH.

I think that was the scariest situation that I had until now. I have no problem with losing connection, I happened a lot of time, RTH works great, but wind warning about "unable to return automatically" and in the same time need for RTH (automatic return) is scary.

RTH will be executed, no matter of wind warning, only thing that matters is how strong is that wind and will RTH be able to return the drone.

 

[Meta4]

I'm sure it was an oversight, but consulting UAV first was to do exactly that. In that response I had asked what the maximum wind speed that a Mini should fly in but did not get a response, so I must assume that nobody has that figure in memory.

It's just not that simple.
Figures you see for what the Mini can handle are the top wind speed in which the Mini can hover and hold position.
But hovering and holding position doesn't bring your drone home.
Whether you get your drone back depends on windspeed, direction of the wind and the distance to home.

The specs for the Mini show:
Max Speed (near sea level, no wind)

13 m/s (29 mph) (S Mode)​

8 m/s (18mph) (P Mode)​

What this means is that in P Mode, if your Mini was fighting against a 4 m/s headwind, it would only be able to make headway against the wind at 4 m/s
If the Mini was only 100 metres away, that's no big deal.

But if you planned poorly and found your drone was 2000 metres downwind, in P Mode, it would take 8.3 minutes to cover that distance against a wind of 4 m/s.
If you still had signal, you could switch to Sport Mode and the drone would make 9 m/s headway (but burn battery faster).
If you lost signal, the drone would attempt to RTH and only make 4 m/s headway.
Whether it gets home or not depends on how much battery is left.

If you fly the Mini, it's ability to make headway against the wind is less than other DJI drones.
You need to be aware of its limitations and avoid putting your drone into a situation where it won't be able to get back.

 

[BadWolf1]

My setup in failsafe is RTH, the warning does say "unable to RTH automatically". So that would result in step 5 in my case if I was to experience both at the same time?

Yes.
It will try to follow the failsafe process you have given. The wind warning is basically saying "Fail safe may not get home" It will still try, because the warning is in response to conditions at that moment. When it comes to try to fly home things might be better (or worse).

 

[vindibona1]

It's just not that simple.
Figures you see for what the Mini can handle are the top wind speed in which the Mini can hover and hold position.
But hovering and holding position doesn't bring your drone home.
Whether you get your drone back depends on windspeed, direction of the wind and the distance to home.

The specs for the Mini show:
Max Speed (near sea level, no wind)

13 m/s (29 mph) (S Mode)​

8 m/s (18mph) (P Mode)​

What this means is that in P Mode, if your Mini was fighting against a 4 m/s headwind, it would only be able to make headway against the wind at 4 m/s
If the Mini was only 100 metres away, that's no big deal.

But if you planned poorly and found your drone was 2000 metres downwind, in P Mode, it would take 8.3 minutes to cover that distance against a wind of 4 m/s.
If you still had signal, you could switch to Sport Mode and the drone would make 9 m/s headway (but burn battery faster).
If you lost signal, the drone would attempt to RTH and only make 4 m/s headway.
Whether it gets home or not depends on how much battery is left.

If you fly the Mini, it's ability to make headway against the wind is less than other DJI drones.
You need to be aware of its limitations and avoid putting your drone into a situation where it won't be able to get back.

That all makes sense. You should also mention that as the battery drains the power to the motors reduces and creates additional difficulties. I know that as well. I suspect by next Spring I'll have another drone. I'm really enjoying what I can do with a Mini, but do recognize it's limitations. As far as taking it "2000 metres downwind" it's highly unlikely that I would take it that far until I get far more experience. By that time I expect to have something a bit more heavy duty.

I find it curious as to why on the forum, wind speed is often quoted as m/s as opposed to km/h or mph? Before flying I always consult my UAV app and it provides windspeed in mph. I believe that general aviation, at least in the US is customarily stated in "knots" 1 knot= 1.150779 mph ( 1.852 kph), mph being close enough for guestimates. I suppose m/s might make sense in the drone world with shorter distances and slower speeds than other aircraft. But even so, in America we haven't weaned off of the Imperial system, though mandated in the 60's. Inquiring minds want to know.

 

[Meta4]

That all makes sense. You should also mention that as the battery drains the power to the motors reduces and creates additional difficulties.

Your drone should fly and climb just as fast at 20% as it does at 100%

I find it curious as to why on the forum, wind speed is often quoted as m/s as opposed to km/h or mph?

DJI specs give the max speeds for many of their drones in m/s.
Metres/sec makes calculations very easy.
And there's also this:

Before flying I always consult my UAV app and it provides windspeed in mph.

Look at the settings and you'll probably find that you can select from a range of units.

 

[vindibona1]

Look at the settings and you'll probably find that you can select from a range of units.

>>>Metres/sec makes calculations very easy.<<<
Mathmatically perhaps. But practically? Not for many. In 2012 I lived in Mexico and even owned a car there, which has fully integrated the metric system. But as someone who psychologically relates to distances in speed and often (but not always) in the Imperial system, while I could do the math and didn't need to do conversions while drivng because the speedometer was in kph and the gas stations dispensed in liters. I remember driving 80kph on the Anillo Periferico and remember feeling a disconnect as it felt slow as h*ll while the speedo read 80. I suppose I will always find metric annoying as I have no physical/mental relationship to it. I tried settign my UAV app to m/s and felt like I might as well have been reading Chinese.

 

[Starsky1970s]

Happened to me. I think it was the first time that I had that warning, and few seconds after that I lost signal with the drone (because of the distance). I panicked a bit, but I did the only thing that I could - I waited. After some time connection was established and I saw that drone is returning. Apparently wind was not that strong and Mini successfully executed RTH.

I think that was the scariest situation that I had until now. I have no problem with losing connection, I happened a lot of time, RTH works great, but wind warning about "unable to return automatically" and in the same time need for RTH (automatic return) is scary.

RTH will be executed, no matter of wind warning, only thing that matters is how strong is that wind and will RTH be able to return the drone.

That is good to know, so all is not lost and the MM as it is still trying to RTH even with the unable to RTH automatically wind warning and fail safe initiated.