Zig-zag to return against strong winds? Uhhhhh...

[EpicFlight]

...I don't think so. Help me out if I'm missing something.

In a TechRadar article comparing the Mini 3 to the Nano+, they said this:

"In wind gusts of over 20mph, the Nano+ can struggle when flying into the wind and it can be necessary to lower altitude and take a zig-zag route back to the take-off site."​

A drone is not a sailboat. The force vector analysis has nothing in common. There's no centerboard.

"Tacking" a drone against a headwind will only waste power, velocity, and time moving perpendicular to the intended course. It will make slower progress to the target than a straight course. A situation where a drone has barely enough energy left to make it back straight on will not if energy is wasted zigzagging.

If caught downwind, the best procedure is to fly as low as safely and legally possible on a course direct to the landing spot.

 

[EyesWideShut]

One idea. I can see the drone's profile to the wind and possibly the wind resistance changing when tracking. Rather than the blunt nose down going straight into the wind, the resistance might be less if the aircraft is at an angle and tilted into the wind. The experts will chime in here and tell me why this is wrong...

 

[old man mavic]

this topic has been discussed on several occasions quite a while ago,and it as you say will not help in the sort of situation you mentioned, the problem with the idea, is that if the wind is strong enough to stop forwards progress home actually flying in a zig zag pattern ,gives the false impression that the drone is coming home but really it is being blown sideways on each leg of the zig zag and as you say flying a lot further ,i as someone who has sailed both RC and full size boats over the years did think that using the tacking analogy of sailing into the wind ,would work in the same way for a drone ,until someone much more knowledgeable than me pointed out the futility of doing it

 

[EpicFlight]

As a sailor, you know what happens sailing if you pull the centerboard, and then try to tack cross-wind at all. (for fun, old movie reference: "I'm a Sailor, I sail!")

That's what I was referring to about the force vector analysis – a sailboat pushes against the water with the centerboard when tacking, something there's no equivalent for on a drone.

EDIT: emailed TechRadar... hopefully they'll correct it.

 

[Phantomrain.org]

So, having flown in 40 mph , there is some truth to this Zig Zagging approach .

When your trying to get your drone back over the water all you want is some kind of forward motion , and if that means running down the beach to get your drone , that that is what you must do as I have shown in a few videos.

Phantomrain.org
Gear to fly in the Rain.. Land on the Water and Zig an Zag if you have to get your drone back.

 

[old man mavic]

what would really be the answer here ,would be to not fly out over the ocean when there is an off shore wind blowing ,and of course in the case of a large body of water such as a lake or reservoir
then it would be fine to fly across the direction of the wind to reach the land further round the edge or to benefit from some shelter from the oncoming wind by some tall trees or other tall structure ,and then zig zag keeping in that sheltered area as much as possible

 

[Yorkshire_Pud]

Think of a boat in a river, the top speed of the boat relative to the water is 10mph. The boat is caught in a spate that is flowing at 11mph relative to the bank. If the boat tries to move upstream at full speed it will, relative to the bank, still be going backwards at 1mph.
If it angles across the river it uses some of that 10mph to move across the river and loses some upstream headway, i.e. it will be washed down stream all the faster.
Same thing applies if you send a dog into a river, walk down stream calling to the dog otherwise the dog may wear itself out trying to get back to you by swimming up stream.

Alternative explanation

 

[EpicFlight]

So, having flown in 40 mph , there is some truth to this Zig Zagging approach .

When your trying to get your drone back over the water all you want is some kind of forward motion , and if that means running down the beach to get your drone , that that is what you must do as I have shown in a few videos.

Phantomrain.org
Gear to fly in the Rain.. Land on the Water and Zig an Zag if you have to get your drone back.

If this were true, then being at a dead stop at full throttle would allow progress in that direction by flying at an angle to the wind?

Explain those physics, please. Remember, to the drone there is no wind. At all.

 

[Eagle Eye 62]

I always make sure I fly into a strong wind so I will be going downwind on my way home or I don't fly at all.

 

[EpicFlight]

I always make sure I fly into a strong wind so I will be going downwind on my way home or I don't fly at all.

Or fly a DJI FPV.

There is that

 

[Meta4]

One idea. I can see the drone's profile to the wind and possibly the wind resistance changing when tracking. Rather than the blunt nose down going straight into the wind, the resistance might be less if the aircraft is at an angle and tilted into the wind. The experts will chime in here and tell me why this is wrong...

It would be more correct to talk about air resistance (or drag) ... the friction that slows the progress of the drone moving through air.
Your drone has to deal with wind resistance even on a perfectly calm day with no wind.

If your drone presents a larger cross section frontal area to the air, that would only increase drag.
DJI's designers have already sorted this out for you and the blunt nose of the drone presents the smallest frontal area to the air that the drone is passing through.

 

[Meta4]

So, having flown in 40 mph , there is some truth to this Zig Zagging approach .

When your trying to get your drone back over the water all you want is some kind of forward motion , and if that means running down the beach to get your drone , that that is what you must do as I have shown in a few videos.

Perhaps you are trying to suggest flying a path to the closest land rather than fly a longer distance directly into the wind to get home?
If so that's something very different.
There is absolutely no truth in the idea that zigzagging can help battle against a strong wind.

 

[Capt KO]

When over water, I agree that flying to the side to gain forward motion, to find land, is beneficial. May not be “home” but it will be recoverable. Best is to not get in that position of returning into high winds. I use UAV Forecast before flight. Many scary stories have been told on these forums of lost and saved drones in this same situation. Never saw zig zag as a viable solution.

 

[EpicFlight]

Actually, if you're over water and you're in a questionable battery situation to return home, you should fly straight for shore and stay over land to return home.

Better to be able to select and execute a controlled flight to some emergency landing spot, then maybe have a long drive around a big lake than drop it in the drink.

Believe me, I know

 

[James G.]

Closest distance between two points is, a straight line. Basic common sense.

 

[Merrill277]

Think of a boat in a river, the top speed of the boat relative to the water is 10mph. The boat is caught in a spate that is flowing at 11mph relative to the bank. If the boat tries to move upstream at full speed it will, relative to the bank, still be going backwards at 1mph.
If it angles across the river it uses some of that 10mph to move across the river and loses some upstream headway, i.e. it will be washed down stream all the faster.
Same thing applies if you send a dog into a river, walk down stream calling to the dog otherwise the dog may wear itself out trying to get back to you by swimming up stream.

Alternative explanation

Drop your elevation for less wind in general. That is why wind generators are on tall poles.

 

[Zbip57]

Picture two people in calm water in a swimming pool. It's a race to see who can swim the quickest from one end to other. One person swims in a straight line, the other does a zig-zag pattern. Obviously the straight line is always going to win.

Now picture the same two people floating in the ocean far from shore with no visible reference points. The water could be dead still, or they are being carried away by a strong current. With no clouds or landmarks in sight they have no frame of reference and have no idea that they're being swept along by the current. As far as they can tell, they're simply floating in dead calm water.

They both decide to swim in the same direction. It doesn't matter if that direction is with the current, against the current, or across the current. One swims a straight line, while the other swims in a zig-zag pattern. The straight line is ALWAYS going to make better progress through the water than a zig-zag pattern. Even if the current is moving faster than either of them can swim, the straight line swimmer is STILL always going to leave the zig-zag swimmer behind.

I can see the drone's profile to the wind and possibly the wind resistance changing when tacking.

Even if you're convinced that there's less wind resistance in the drone's profile when flying sideways, versus flying blunt nose forward, then it still makes more sense to fly sideways in a STRAIGHT line rather than zig-zagging.

 

[Drones.n.Pixels]

I would say that this could only work if one part of zigzag gets you closer to land, other gets you closer to home (without moving further from land). Otherwise I don't think it's worth effort and risk.

 

[edfrombama]

Good evening to all-
This is a very interesting discussion.
I think the folks who might be confused by the basic "zig zag" against the wind proposition of returning a drone are sailors who have spent time tacking against the wind.
The big difference, of course, as previous posters have pointed out, is that sailboats use the force of the wind as the power to move. The boat supplies nothing but sail and centerboard and rudder. Sailboats can move into the wind only by "zig-zagging" in some manner.
But drones don't use the force of the wind as power- just the opposite. So zig zagging the drone. unless as previous posters have pointed out to bring the drone from over water to over land for a better emergency landing is just not a good idea.
That old wind can be not your friend at times- at least, when you're drone flying.

I reckon the best idea for a drone flier to do is first thing in the morning when you plan to fly announce to the world "I'm going SAILING today!" If it works as it does for me, there won't be a puff of a breeze- flat dead calm.
And when you want to go sailing, announce to the world, "I'm going drone flying today!" There will be a God's plenty of wind.
Count on it..


Good night to all- Ed