Strong Wind RTH

[frcaloy]

Has anyone experienced executing a RTH with strong winds?

or

The App said that automatic RTH is disabled when I flew my Air2 this afternoon. What will happen if I lose signal during strong winds?

 

[old man mavic]

@frcaloy always try to fly into the wind on the outward leg of your journey if at all possible
any triggered RTH whether it be signal loss between the RC and the drone or remaining battery to get back home ,then the moment one of those events takes place then the drone depending on its altitude at the time will either come back at that height or if it is lower than the preselected height climb first to that height ,and then attempt to RTH ,as you may be aware the wind strength tends to increase with altitude, so the drone would not be able to get back to the home point ,if the wind was to strong for it to make any headway
you can cancel the RTH ,loose altitude as much as the surroundings will allow, and fly the drone home manually,in normal mode (sport mode may be faster ,but uses more battery)
or you could try to find a safe location to land the drone and then retrieve it

 

[slup]

...The App said that automatic RTH is disabled

The wording DJI have there is misleading ... & it isn't quite like what you remembered either.

This is what's stated in the app ...


If you put in a "may be" between "Aircraft & unable" you get it correct.

What will happen if I lose signal during strong winds?

If the headwind is faster than what your drone can achieve in the RTH mode it will be blown backwards while it continuously trying to make headway towards the HP, this will continue until the battery is depleted & the drone auto lands. Another scenario is that the headwind slows your drones ground speed down to the degree that the battery gets drained before reaching the HP & instead auto lands.

Tailwinds is normally no problem, your drone tries to keep it's max speed for the RTH mode through pitching up slightly to brake but it will reach HP without any drama.

 

[Yaros]

Has anyone experienced executing a RTH with strong winds?

Yes, it highly depends on the altitude and the wind & flight direction.

If it is returning with the wind, it will RTH no problem.

Another story if it needs to RTH against the wind.
Of course, it will try to RTH in any situation, it will not give up until forced landing because of battery.
There if the wind at the RTH altitude is stronger than the maximum speed in Normal/RTH mode (around 40 km/h for Air 2) it will struggle to return, or might even be stuck. If the wind is lower than the maximum speed, it will fly slower, but still return.

I highly suggest using Sport mode to return against the wind!

 

[Yorkshire_Pud]

I have had a Mavic Mini RTH into a head wind whilst wind warnings were being issued and the Mavic Mini is possible the most wind susceptable of the DJI drones.
What you need to do is keep an eye on whether or not the drone is actually reducing the distance to the home point and, if it is, how quickly it is doing so. Plus you need to check how quickly the battery is draining.
If you get the impression it is questionable as to whether or not the drone will make it home then you need to take action.

The normal approach is to reduce the drone's height, this tends to move the drone into slower wind. It is also useful to switch to sports mode, which allows the drone to use greater airspeed. But note, changing flight mode generally cancels an on going RTH.
If the RTH was started whilst the drone was in sports mode you may be able to give the drone greater airspeed by giving it full forward elevator, automated RTH speed tends to be 'not fast'. It might be an idea to check this on a windless day as some of the recent app updates have started to mess with how drones respond if given stick inputs whilst the drone is RTHing, besides, it may be a model dependant feature.

The above said I have seen my Mavic Mini blown backwards despite full forward elevator in sports mode and then the only thing you can do is reduce its height and hopefully get out of the high speed wind. In my cases it was gusts and they soon blew through but I had reduced the drone's height before the gust/s blew through and had got the drone into slower air.
I still have the drone.

If it is windy, it is, as has been suggested, better to fly the out bound leg of a flight up wind and with that in mind I did fly the Mavic Mini up wind on a windy day then initiated an RTH. It was quite interesting/odd to watch it RTH in almost the hover position and perhaps occasionally attempt to fly 'backwards', to slow down, i.e. the wind speed was near or greater than the automated RTH speed.

If the drone is caught in wind and can not beat it no matter what the height nor the drone's airspeed you need to get the drone on the ground safely, where ever possible, even if it is in a controlled crash, whilst the drone is within control range. If you lose connection in wind that is consistantly too strong for the drone to fight the drone will be blown away, there have been multiple instances of this happening and quite a few are discussed either here or on the DJI forum. A 'lot' of early Mavic Minis were blown away.

For the same reason I suggest that excessive RTH height is unwise, i.e. it runs the risk of putting the drone up into high speed wind, (plus it wastes energy in climbing to and descending from excessive height).
I generally set a new RTH height for every new location and aim to clear obstacles by 5 to 10m.

I had a Phantom 3 blown away in a persistant gust. It was heading towards a village and I do not fly over such things. I could not reduce its height because it was already close to roof height.
I was literally seconds away from flying the drone across the wind and out to sea, in order to ditch it into the sea using the CSC, when the gust died and the drone began to make headway. As soon as the drone was 'home' I landed it and packed up for the day.

 

[LoudThunder]

Has anyone experienced executing a RTH with strong winds?

I've said it before and I will keep saying it. If you fly in strong winds, you may lose your drone or damage it trying to return and land it…

When I suspect wind, I lift off and turn my drone directly North. Then I rise up to 50' and check the Atti Gauge and see if my drone I struggling to stay in place, then to 100' and then again check the Atti Gauge for hints of the drone having to heave over to stay in place or it looks like it is flying at full speed to stay in place. I keep going higher if it's safe and keep checking, it the drone is struggling; I'm not going to fly down wind to see if I have enough battery power to fly back when the headwind is near the max speed of the drone. And if the headwind is higher than your max speed, your drone will be flying backwards going full speed forward.

Besides using UAV Forecast, I also use Windy - Weather Forecast available in the App Store. Here is a screen shot I just took…



And here is the link to the App…

Windy.com - Weather Forecast - Apps on Google Play

Weather radar, satellite, wind, waves, marine and hurricanes forecast.

play.google.com

 

[frcaloy]

Thanks for the input.

I still had 70% battery power when I received the message of strong winds. I manually flew the drone back to home point. I am just wondering what the drone would do if it loses signal since the message says that the drone is unable to return home automatically.

 

[frcaloy]

I am a certified private pilot and I own a Cessna 150. There is a saying that all winds are headwinds.
Say you have to fly from point A to point B distant 120 knots from each other. If the average airspeed is 80 knots per hour, the trip is going to take 1 1/2 hours so 3 hours back and forth in windless conditions (which never happen).

Say there is a 15 knot headwind on one leg, making the average speed for that leg 65 knots, the travel time would be 1 be 51 minutes. You would think that the tailwind would cancel out the delay on the return home leg but that is not the case. The average speed on the return home would be 95 knots with a tailwind giving us a flight time of 1 hour 16 minutes. Total flight time is 3 hours 7 minutes. All winds are headwinds. The reason is that the headwind has MORE time to act AGAINST your aircraft and LESS time to act WITH your aircraft.

Glad that I did not learn that the hard way in a real world aircraft. The Cessna 150 has around 4 hours flying time and I am usually comfortable with a 1 hour fuel reserve for long queues in the traffic pattern or other reasons.

In the case of drones, I execute a return to home at 65% battery time but that's just me.

From a previous thread

 

[LoudThunder]

Glad that I did not learn that the hard way in a real world aircraft.

You are a pilot and you know what happens when you run out of fuel (as in battery in your drone…), it's going down…

If the winds are so strong that your drone will not perform a RTH, and you lose connectivity, then your drone will hover and do it's best to stay in position. But if the wind is so strong, it might push your drone along like a helium balloon in the wind. And when that battery is critically low, your drone will land…

Ad if you lost contact with your drone, you will only know its last position previously to loosing contact and if the wind pushed it, you had better have a good guess which way the wind was blowing so you can track it down; and you had better hope it was not over tall trees, water, or an impregnable forests…

Have you ever tried to use the Find My Drone function in the map and turning on the flashing and beeping. If it's bright outside you will never see the flashing and if the wind is blowing, you might not hear the beeping…

If you have never used it, you NEED to try it in a controlled situation. Fly your drone a ways away, land it and then activate the Find My Drone and start the flashing and beeping.

You are a pilot and you know you never try an emergency procedure for the first time during an emergency… You practice it so it is second nature.

Now, go find your drone…

 

[frcaloy]

You are a pilot and you know what happens when you run out of fuel (as in battery in your drone…), it's going down…

If the winds are so strong that your drone will not perform a RTH, and you lose connectivity, then your drone will hover and do it's best to stay in position. But if the wind is so strong, it might push your drone along like a helium balloon in the wind. And when that battery is critically low, your drone will land…

Ad if you lost contact with your drone, you will only know its last position previously to loosing contact and if the wind pushed it, you had better have a good guess which way the wind was blowing so you can track it down; and you had better hope it was not over tall trees, water, or an impregnable forests…

Have you ever tried to use the Find My Drone function in the map and turning on the flashing and beeping. If it's bright outside you will never see the flashing and if the wind is blowing, you might not hear the beeping…

If you have never used it, you NEED to try it in a controlled situation. Fly your drone a ways away, land it and then activate the Find My Drone and start the flashing and beeping.

You are a pilot and you know you never try an emergency procedure for the first time during an emergency… You practice it so it is second nature.

Now, go find your drone…

Haven't lost a drone yet. That's why I'd like to know what the drone would do if it loses signal in high winds.

I returned home immediately after receiving the message of strong winds.

 

[Meta4]

That's why I'd like to know what the drone would do if it loses signal in high winds.

Your drone would initiate the Loss of Signal action that is in its settings.
The default is RTH and unless you've changed that to something else, the drone will attempt to RTH.
Return will depend on battery level, wind strength and direction and distance from home.
One other thing to consider is the RTH height you have set.
If you ever find yourself in a headwind situation coming home, you don't want the RTH height set too high.
Higher altitude = stronger winds.

And you can bring the drone back manually faster than RTH will fly it home.

 

[Cymru]

you can cancel the RTH ,loose altitude as much as the surroundings will allow, and fly the drone home manually,in normal mode (sport mode may be faster ,but uses more battery)

One slight correction there, it may depend on the drone but in some headwind conditions it maybe impossible to make any headway in normal mode. In which case, switching to sport is the only way to get it back.
Sometimes you need that extra pitch.

My general rule is my LOS RTH is set to about 200ft. If its a windy or gusty day i lower that to just above the expected obstacles to give it a better change of getting home if something does happen.

 

[coullit]

@frcaloy always try to fly into the wind on the outward leg of your journey if at all possible
any triggered RTH whether it be signal loss between the RC and the drone or remaining battery to get back home ,then the moment one of those events takes place then the drone depending on its altitude at the time will either come back at that height or if it is lower than the preselected height climb first to that height ,and then attempt to RTH ,as you may be aware the wind strength tends to increase with altitude, so the drone would not be able to get back to the home point ,if the wind was to strong for it to make any headway
you can cancel the RTH ,loose altitude as much as the surroundings will allow, and fly the drone home manually,in normal mode (sport mode may be faster ,but uses more battery)
or you could try to find a safe location to land the drone and then retrieve it

 

[coullit]

Good advice also common sense
I’ve never lost rth with dji app or better litchi app for vr flying

 

[old man mavic]

@Cymru ,i agree that sport mode is going to enable the drone to overcome the wind better than it can in normal mode ,but that also comes at a price of depleting the battery at a quicker rate,my RTH height is set at 40m ,which i find covers most of the places i fly
what needs to be done to try and get the drone home ,is ultimately going to depend on several factors ,and those can only be made on the day ,when the issue of RTH happens ,the choice of which speed mode one chooses is going to depend also on the conditions at the time

 

[Yorkshire_Pud]

then your drone will hover and do it's best to stay in position.

Assuming the air 2 is similar to other DJI drones, whether or not that happens depends of the failsafe option setting. In most cases this will be RTH and such an air 2 suffering a loss of connection will attempt to RTH.
It would only hover IF the failsafe option is set to hover, however even then it will only hover until the low battery RTH kicks in and then it will RTH. I tested this with a Mavic Mini and possibly an M2P/Z.

@frcaloy just a point with regards to your comparison with the Cessna.
The Cessna's motor will, or perhaps should, run 'perfectly' happily until the fuel is exhausted. A DJI will not. Whilst there is still fuel/charge, but only a little, you may lose speed as the drone's software may limit power consumption to avoid damage to, perhaps, the battery. I forget the precise warning that is issued.
Beyond that point there is a charge percentage at which the software decides there is only enough charge to land the drone. At that point the drone will, if left to its own devices, start to land and make no further attempt to RTH.
This can, to some extent, be overridden by giving commands with the controller but speeds are SEVERELY limited and a lot of throttle must be given to keep the drone in the air. The drone will continue to fly in approximate accordance with the instructions issued by controller, or descend if the controller issues no commands, until the drone lands and do so until the battery is well below 0%.
Again there are you tubes etc. showing this and is some instances pilots, caught out over water etc. have saved their drone by commanding full (available) speed etc. and got their drone over land.
But, at a certain point the drones' software will decide that enough is enough and literally stop the motors even if the drone is still in mid air.

 

[Cymru]

@Cymru ,i agree that sport mode is going to enable the drone to overcome the wind better than it can in normal mode ,but that also comes at a price of depleting the battery at a quicker rate,my RTH height is set at 40m ,which i find covers most of the places i fly

With the Mini 3 for example here its perfectly possible to be making 0 or 1m/sec at full power into a wind. Battery time alone will run out before it gets back home, if ever.
However flicking to sport mode, allowing that extra pitch means it GET get home before depleted. The pitch helps, not just the power.

 

[Reginald E Johnson]

That works for me! Good advice and be prepared to go and get it!

 

[Dbez1]

Good advice above. I just want to point out that while I did experience high wind warnings when I had my Mini1, I’ve never seen one during the many flights of my Air2 and later, my Air2S. If a pilot is getting these warnings too often, he/she might want to reevaluate his risk assessment procedures. I’m just pointing this out for the benefit of new pilots and not the OP.

 

[Yorkshire_Pud]

Good advice above. I just want to point out that while I did experience high wind warnings when I had my Mini1, I’ve never seen one during the many flights of my Air2 and later, my Air2S. If a pilot is getting these warnings too often, he/she might want to reevaluate his risk assessment procedures. I’m just pointing this out for the benefit of new pilots and not the OP.

The first time you see your drone moving backwards whilst flying as fast as possible forwards the message gets driven home lol, it's an "oh sugar" moment.
I think DJI errs on the side of caution, which is a good thing and the messages should not be ignored but they need not be the cast iron truth.