Coming back down through fog?

[R1Mavic]

I’ve been told that going up through heavy fog could cause an issue coming back down. Something about the sensors preventing the drone from entering it. Any truth to this?

 

[BigAl07]

More importantly how are you remaining legal and maintaining VLOS flying through/over fog?

 

[karlblessing]

Downward vision sensor might confuse it as being solid ground and think you're attempting to land. As a result it can possibly trigger landing as you keep pulling down on the stick and crash as the motors shut off well above the ground.

And flying thru fog in general is not good, not just because of inability to keep visible line of sight, but because its similar to flying in a downpour that water droplets get in everything and can potentially short the battery if you don't have any kind of extra protection over the button or battery seams.

 

[R1Mavic]

Downward vision sensor might confuse it as being solid ground and think you're attempting to land. As a result it can possibly trigger landing as you keep pulling down on the stick and crash as the motors shut off well above the ground.

And flying thru fog in general is not good, not just because of inability to keep visible line of sight, but because its similar to flying in a downpour that water droplets get in everything and can potentially short the battery if you don't have any kind of extra protection over the button or battery seams.

I bet you’re right. Essentially what was discussed.

 

[Yaros]

I've flown above and though fog a couple of times. Didn't keep VLOS though, no need to say anything to me on that one, was my fault.

Anyway, to go down, I just put it into sport mode, and flew down and forward at the same time, or just down normally works, if you get stuck, switch into sport mode and go forward and down at the same time.

 

[Meta4]

I’ve been told that going up through heavy fog could cause an issue coming back down. Something about the sensors preventing the drone from entering it. Any truth to this?

There have been many cases where flyers are unable to bring their drones down after going up in fog.
If the fog is heavy enough, the downward sensors detect it as an obstacle below the drone and landing protection slows the descent significantly.
In extreme cases some have gone high and not been able to descend before the battery runs out.

Another issue that shows up every winter is flyers getting into trouble flying in moist cold conditions.
Propeller icing happens in these conditions and can cause big problems when the drone just stops flying.

Anyway, to go down, I just put it into sport mode, and flew down and forward at the same time, or just down normally works, if you get stuck, switch into sport mode and go forward and down at the same time.

Think again.
Sport Mode makes no difference to the downward sensors which detect the fog as a solid obstacle.
You were just lucky that the fog was light enough to avoid the potential problem.
It's not possible to disable the downward sensors on any DJI Fly drone.

 

[karlblessing]

It's not possible to disable the downward sensors on any DJI Fly drone.

You can physically block them with gaffer tape or other thick opaque tape. But at least one thing happens : you can't land normally anymore, usually have to hand catch. And the other least in some models like the Minis, goes into Atti mode so inertia/wind etc just has the drone drifting ever which way if you're not diligent in countering it continously.

 

[Meta4]

in some models like the Minis, goes into Atti mode so inertia/wind etc just has the drone drifting ever which way if you're not diligent in countering it continously.

It's hard to see how blocking the downward sensors would have any effect on GPS ??

 

[karlblessing]

It's hard to see how blocking the downward sensors would have any effect on GPS ??

Probably because 90% of the YouTube videos I observed demonstrating it, are doing it indoors. Which would have relied visual positioning system in those cases (weak signal to begin with), and the initial reason for blocking the sensors would be to allow for tighter or lower fly thrus in such an environment.

So yes I'm sure if you had it out in open air it would just be dependent on GPS, but there's usually very little reason to need to block the downward sensors in outdoor open space.

Initial point is, there is a way to disable/block the downward sensor, just not thru the software.

 

[twickers14]

Very helpful thread. We have fog today and I said to the wife I fancy a flight to see how it goes. My instincts told me not to do it due to moisture, VLOS and sensor issues. The above makes my mind up. Thanks.

 

[Lets Fly]

More importantly how are you remaining legal and maintaining VLOS flying through/over fog?

Remember all fog situations are not the same. I don't get many foggy days here but when I do it's not that thick. Went to 300 feet and had the great view and could still see the bottom light. When I looked down I can see my house. So it depends on the situation. Breaking out above the fog or coming back down is a unique flying experience.

 

[BigAl07]

Remember all fog situations are not the same. I don't get many foggy days here but when I do it's not that thick. Went to 300 feet and had the great view and could still see the bottom light. When I looked down I can see my house. So it depends on the situation. Breaking out above the fog or coming back down is a unique flying experience.View attachment 157712View attachment 157713

I wasn't going to derail this thread but your post pretty much changed that thought process.

In that picture, do you honestly believe you have FULL VLOS of the aircraft and the air around it? Also you're assuming there is no fog between your aircraft and other aircraft in the area.

I can assure you that if there is an incident with your UAS and the obscurity is even remotely as horrible as your picture indicates, you are FULLY at fault.

Remember maintaining VLOS is more than being able to see those tiny blinking lights on your aircraft.... you have to be able to see fully AROUND the airspace you're flying in AND you have to have CLEAR AIR/Visibility so that OTHER aircraft can see your UAS. Remember Aviation Safety is about much more than just your UAS... actual LIVES could be changed from your decisions.

 

[karlblessing]

Remember all fog situations are not the same. I don't get many foggy days here but when I do it's not that thick. Went to 300 feet and had the great view and could still see the bottom light. When I looked down I can see my house. So it depends on the situation. Breaking out above the fog or coming back down is a unique flying experience.View attachment 157712View attachment 157713

In this example, you might be able to see it directly below. But you most definitely didn't have 2+ miles of visibility which as I understand, isn't a recreational requirement while VLOS is, but definitely a requirement for Part 107 (in general just the safe thing to ensure either way).

Also if the same density as shown were near freezing it would not take much at all to ice up the props.

So course the fog density may vary, but in the long run, is it worth the risk?

 

[Lets Fly]

I wasn't going to derail this thread but your post pretty much changed that thought process.

In that picture, do you honestly believe you have FULL VLOS of the aircraft and the air around it? Also you're assuming there is no fog between your aircraft and other aircraft in the area.

I can assure you that if there is an incident with your UAS and the obscurity is even remotely as horrible as your picture indicates, you are FULLY at fault.

Remember maintaining VLOS is more than being able to see those tiny blinking lights on your aircraft.... you have to be able to see fully AROUND the airspace you're flying in AND you have to have CLEAR AIR/Visibility so that OTHER aircraft can see your UAS. Remember Aviation Safety is about much more than just your UAS... actual LIVES could be changed from your decisions.

Yes the lights were just visible, I have green and red on the front and whites on the back, but the auxiliary light on the bottom of the M2Z is what I looked for. If I could post the video you would see that I go straight up do a 360 and straight down. I would never fly around on a foggy morning away from home point, and if any manned aircraft were to be flying at 250 or 300 feet with fog, that would be insane. And if an aircraft comes over your house at 300 feet it would be on you before you could react, fog or clear blue sky, but yes, better safe than sorry. Use common sense and also trust your instruments. So ending, I got the picture I was after, and never have to fly that again because the image will always be the same. All constructive criticisms taken seriously, thanks.

 

[Dmcvey]

Since fog is a cloud, flying into is illegal since you have to keep 2000 foot laterally and 500 below a cloud.

 

[karlblessing]

Since fog is a cloud, flying into is illegal since you have to keep 2000 foot laterally and 500 below a cloud.

That only applies to Part 107 operations by the way, that doesn't apply to recreational flights other than it could be lumped under the reckless flight umbrella if something happened.

Also

13.1 Introduction. A cloud is a visible aggregate of minute water droplets and/or ice particles in the atmosphere above the Earth’s surface. Fog differs from cloud only in that the base of fog is at the Earth’s surface while clouds are above the surface

https://www.faa.gov/documentlibrary/media/advisory_circular/ac_00-6b.pdf

 

[edfrombama]

Good morning to all-
I have flown in patchy fog once, and it presented me with some of the best videos I've shot while flying. Amazing seeing the ground disappear and then magically reappear as the drone moved along.
Since I don't concern myself overly with VLOS anyway, this one early morning flight was done safely, easily, and with great results.
But I wouldn't fly my drone in fog such as we have here today- the thick pea-soup variety. Too much like rain- hard on drone electronics. I'll wait until the fog thins and sun shines.

You all be well and keep safe.

 

[Dmcvey]

See here is another 107 vs. hobbyist rule:

Cloud ceiling at 400': 107 pilot grounded, must be 500 below cloud. Hobbyist is flying. Same risk to other aircraft that may be in the area but 2 sets of rules. Is the hobbyist less of a risk than the 107 to fly in the same conditions?

 

[karlblessing]

See here is another 107 vs. hobbyist rule:

Cloud ceiling at 400': 107 pilot grounded, must be 500 below cloud. Hobbyist is flying. Same risk to other aircraft that may be in the area but 2 sets of rules. Is the hobbyist less of a risk than the 107 to fly in the same conditions?

Only in the sense they don't have the pressure to get the job done. But otherwise I see both as equally unsafe.