Loss of orientation on overcast/cloudy days

[PaoloFCantoni]

In the "What did you do to your Blade 450X today?" thread, I found:

Originally Posted by megawhacker

Four flights yesterday at the club field. Four more today. Up to 28 450X flights now since the maiden last month.

Sunny both days. No orientation losses. Apparently, this hobby is easier against a blue sky than against an overcast.

[SNIP]

Originally Posted by MrRoboHeli

I completely agree. My 450X crash this summer was caused because I lost orientation. It was against a gray & overcast sky as well. I was really surprised by it because I never had that kind of uncertainty when flying against a blue sky.

I had recently come to the same conclusion after the last few crashes.

Have others observed this also?

My theory is that (I believe) the light coming through the clouds is polarised (I think I read or heard that somewhere) and that affects the visibility of the heli if it's at a distance.

Any thoughts? If you agree, were you wearing polarised glasses at the time also? In my case, although it was overcast, it was also very glary. So I put on the polarised glasses.

TIA,
Paolo

[meowguy]

Yes. This is pretty well known as the cause of many crashes because without bright sun you can easily confuse a heli going away with one coming toward you. A single moment of distraction can cause confusion. If you are too low it will almost always result in a crash. Being higher in the sky only makes the situation worse but allows at least a little more time to recover. On these type of days keep it closer and keep the routine simple. A better day will come if you still have a bird to fly.

[Nelsonisms]

Besides the obvious that clouds block light, I also think that it has something to do with our brain's ability to differentiate foreground patterns from the background noise. A cloudy sky has a lot of variation in color, brightness and texture. So the model kind of gets lost or mixed up in that. When it's clear blue there are less variations for our eyes to decipher and so the model really sticks out and our brains are able to process it more efficiently. I guess it would be similar to reading text off a piece of plain white paper versus one that was printed with an abstract pattern behind the letters.

Maybe it's sort of similar to what's going on in this optical illusion....Induced Grating...

http://www.michaelbach.de/ot/lum-ind...ing/index.html

[ahahn]

Originally Posted by PaoloFCantoni

In the "What did you do to your Blade 450X today?" thread, I found:





I had recently come to the same conclusion after the last few crashes.

Have others observed this also?

My theory is that (I believe) the light coming through the clouds is polarised (I think I read or heard that somewhere) and that affects the visibility of the heli if it's at a distance.

Any thoughts? If you agree, were you wearing polarised glasses at the time also? In my case, although it was overcast, it was also very glary. So I put on the polarised glasses.

TIA,
Paolo

Polarization has no impact---unless you are wearing polarized glasses---as you surmise.

I think the main issue is that there are no shadows--clouds tend to provide a very even illumination. Without shadows it is difficult to determine orientations, especially at any distance where you really can't distinguish the small change in perspective.

It is much easier to "big fly" under these conditions than to simply hover at different orientations. I think that's because in forward flight your mind can connect the dots and predict where the hell is going next. When the hell is hovering, you can't really predict the next position so your mind begins to play the various orientation tricks--rotating the tail by 90 degrees so you aren't sure if it is pointing at you or away from you. It certainly can produce those adrenaline moments!

[andycrazy]

Originally Posted by ahahn

It is much easier to "big fly" under these conditions than to simply hover at different orientations. I think that's because in forward flight your mind can connect the dots and predict where the hell is going next. When the hell is hovering, you can't really predict the next position so your mind begins to play the various orientation tricks--rotating the tail by 90 degrees so you aren't sure if it is pointing at you or away from you. It certainly can produce those adrenaline moments!

And I thought it was due to too many strong painkillers!
It was very overcast over here today and I nearly lost it twice, its definately worse when the heli is relatively still in the air than when flying big air fff.

[megawhacker]

Originally Posted by megawhacker View Post
Four flights yesterday at the club field. Four more today. Up to 28 450X flights now since the maiden last month.

Sunny both days. No orientation losses. Apparently, this hobby is easier against a blue sky than against an overcast.

[SNIP]

I commonly use dry humor, understatement, and tongue in cheek. My humor is so dry as to not even be humor.

Yes, "everyone" in this hobby is aware of the phenomena I commented on (including me). My experience at the field on three consecutive days-one overcast and two sunny days, was consistent with what "everyone" knows to happen.

My thoughts on the overcast day was that I need a colorful boom and tail. (Or maybe I need to maiden one of my 550's) On the two sunny days, the stock white colors served me reasonably well. I do have a very colorful Fusano canopy which helps immensely. A colorful tail would help even more, I imagine.

I enjoy reading the thoughts of others in this thread regarding the overcast phenomena.

I always assume that my natural ability is in the bottom 10% of RC CP helicopter pilots and that orientation is more challenging for me than for most.

[andycrazy]

I have the fusuno fibreglass vertical fins on all my helis, yelow and orange work well. It does make it easier but it does not totally solve the problem.

[jbrandt]

Originally Posted by andycrazy

I have the fusuno fibreglass vertical fins on all my helis, yelow and orange work well. It does make it easier but it does not totally solve the problem.

I wonder if there's such a thing as going "too bright" with the colors.

I've noticed that some uber bright colors tend to "blur" a little, but maybe that's just my dysfunctional eyes...

[Nelsonisms]

Originally Posted by jbrandt

I wonder if there's such a thing as going "too bright" with the colors.

Absolutely...

[jbrandt]

Originally Posted by Nelsonisms

Absolutely...

okay, thanks to you I'll never fly again, as I just scratched my eyes out.

[RoboHeli]

LOL. Love it.

I also surmise that having direct sunlight shining on the heli helps increase it's visibility. When I crashed this summer, the heli was at the far end of my field and it had started to roll over to the left (most likely my fault) but I couldn't see it doing so. The blade disk was completely invisible against the cloudy sky and the white/black tail/fin/skids didn't give me enough visual cues as to what was happening until it was too late. The heli had rolled over at an angle and was heading towards the ground too quickly for me to correct in time.

I've since put on a neon green tail fin from fusuno and wrapped the back part of my tail boom in neon green adhesive plastic. I'm also now flying Vector RJX blades that have a white/green color paint job on them. I might try the Zeal black/green blades sometime soon as well. Here's hoping I don't lose orientation like that again! At least I'm aware of this kind of situation occurring and so I can watch out for it.

[Crakin]

Learning sky conditions is part of the learning curve. Try shooting range glasses, you know the ones that washed up martial artist likes to wear indoor. But really you are just trying to put a band aid on the problem, which is lack of confidence.

Your heli does not change direction just because you lost perception for a brief moment. Once you have the confidence to fly through the lose of vision...well, you fly through it.

[jbrandt]

Originally Posted by Crakin

Learning sky conditions is part of the learning curve. Try shooting range glasses, you know the ones that washed up martial artist likes to wear indoor. But really you are just trying to put a band aid on the problem, which is lack of confidence.

Your heli does not change direction just because you lost perception for a brief moment. Once you have the confidence to fly through the lose of vision...well, you fly through it.

[Crakin]

Originally Posted by jbrandt

That's way better than any of the cheesy Steven Seagal picture I found.

[jbrandt]

Originally Posted by Crakin

That's way better than any of the cheesy Steven Seagal picture I found.

Oh, THAT'S who you were talking about... lol

[RoboHeli]

Originally Posted by Crakin

LYour heli does not change direction just because you lost perception for a brief moment. Once you have the confidence to fly through the lose of vision...well, you fly through it.

No, the heli doesn't change direction just because I lose my orientation. However, if it starts to roll over (in my case) but I can't see it doing so, then yes, I've got a problem. I had been thinking about rolling it while doing some FFF but decided not to. What I think happened was that I had started to push gently on the cyclic while not realizing I was doing it and that caused the roll to start just as the heli reached the far end of the field where I found it difficult to see it rolling.

I think I get what you're trying to say. What I know I'm missing is experience. I don't have my inverted orientations down yet and I haven't put enough flights on the 450X yet to really get a solid feel for how it handles in enough cases. It'll all come though. Just need more stick time with it.

(Well, sim time now... it's too darned cold to fly where I am. )

[Crakin]

Originally Posted by MrRoboHeli

started to push gently on the cyclic while not realizing

I do that too and I see that as a confidence issue because it happens most when I tense up.

Being ahead, or flying ahead of your bird is when you will start to notice a difference in confidence, rather than focusing on what the chopper is doing so you might react a certain way. By getting into that reactive state of mind you can almost will something to happen, like hitting an object you are trying to avoid.

There's a video floating around here of the exact thing I'm talking about.

Anyway, once you come to grips with the fact your chopper might only be visible as a silhouette a few times though out your flights, and you anticipate that, it becomes less of an issue that you can't see the bright colors, or whatever visual cues are not there in that moment.

[jbrandt]

The idea of "pushing through" a loss of orientation via experience brings me to this:

That's only true if there are NO external forces acting upon your helicopter, and your helicopter acts the exact same way every time.

Back in my 1:1 fixed wing flying days, I did this thing as a student, where after obtaining straight and level flight, my instructor would blindfold me. The only sense you have is hearing and your equilibrium. After a few seconds the rpm would increase, so you'd instinctively pull up slightly thinking only the nose has dropped, rpms increase more, you pull up more, etc... Because you don't have visual orientation, you think you're just increasing speed, when if fact you have started a turn, but your equilibrium isn't indicating a turn so you think you're just going straight. But that pulling up you are doing is only increasing the rate of turn, and you enter what's called the Death Spiral. If not corrected, you'll, well... die. Even if you are conscious about (likely) being in a diving spiral, to which direction to you give an aileron correction? This happens when pilots loose horizon orientation in heavy fog or at night and don't trust their instruments (or more rarely, have catastrophic instrument malfunctions).

Total elapsed time is 15-20 seconds. The point of the exersize is to learn to trust your instruments, but if those fail even very experienced pilots fall victim.

The point of all this is that without orientation, control inputs can (and generally do) make things worse. You might pull up elevator when what you really needed is left aileron and rudder.

R/C pilots don't have instruments or an equilibrium to give them a sense of direction so maintaining visual orientation is even more important. So while experience will allow you to some degree "push through" a maneuver (by memorizing coordinated stick movements), the increased reaction time and hand-eye coordination that allows a pilot to quickly and seamlessly correct for small variations in attitude (only available with maintaining visual orientation) is really (IMO) what makes a good pilot.

I'm certainly not there yet; the way I fly sometimes it appears that 6 drunken monkeys have taken over the controls.

[Crakin]

I agree.

For example heights intimidate me, my body rejects being in those situation even though my brain may know with a high degree of certainty I'm safe. It always take some time before I can function safely and would probably almost loose balance if I move around before I gain confidence.

If you were to add external forces like wind it just ups my anxiety, making it more likely to loose balance.

[jbrandt]

Originally Posted by Crakin

I agree.

For example heights intimidate me, my body rejects being in those situation even though my brain may know with a high degree of certainty I'm safe. It always take some time before I can function safely and would probably almost loose balance if I move around before I gain confidence.

If you were to add external forces like wind it just ups my anxiety, making it more likely to loose balance.

Funny story:

I used to be extremely acrophobic, that is, (ironically) until I started rock climbing. My brother got me into it and I started climbing at a gym. I quickly got hooked and started climbing outdoors as well. I'm a gear junkie and an engineer at heart, so focusing on the gear and knowing how strong the gear actually is helped me push past the fear of heights. Eventually, I became a climbing guide, and even climbed the southwest face of Half Dome. I still have that twinge in my stomach, those times when I'm about to step over out form the "safety" of a ledge 800 feet high, but that is what IMO keeps me alive. If you're not at least a little afraid, then you're just plain insane.

And yes, I fully acknowledge I have completely highjacked this thread...