Which way do they fly Down Under?
 

Some years back I realized that if I needed an answer to a question, almost any question, but certainly about model avaition - this was the place to got.

I mean this forum verily drips with expertise and wisdom.

SO, a couple of weekends ago when there was a lull in the flying and there was nothing else to do but shoot the bull, someone wondered aloud why is it that most of us are most comfortable flying a left-hand pattern.

There was speculation that it had something to do with the geometry of our well-known opposable thumbs, the effect of torque, or just that's the way we were taught.

But a really, really smart individual wondered out loud if it had something to do with our living in the northern hemisphere and that perhaps the standard pattern was the opposite down below, upside down, in Oz (aka Australia and New Zealand).

Well, I said that I'd go ask youse-guys and that surely I'd get the correct answer lickety split.

So what pattern is most common down under and why?

P.S. Just for the sake of clarification; our definition of the left-hand pattern was to take off from the left (wind not being a consideration) and landing with the model approaching from the left as well.

RE: Which way do they fly Down Under?
 

Left to right is more comfortable for me.

Also works well with the prevailing winds here.

RE: Which way do they fly Down Under?
 

Dripping indeed. :eek:

RE: Which way do they fly Down Under?
 

Because Left Hand Traffic (patern) is standard - without an operating control tower;) Right hand is only used for obsticle avoidance and noise abatement.

Or maybe it has to do with the way the water rushes down the toilet......

RE: Which way do they fly Down Under?
 

Most people worldwide fly control line airplanes in a counterclockwise (CC)direction. Teaching myself, I learned to fly clockwise(CW). I wanted to fly combat which requires flying CC. By that time I was flying inverted, doing maneuvers, etc. I tried to learn to fly CC with the up line at the top of the handle as everyone else in the world does. Crashed one airplane and then turned the handle over and flew with the down line at the top. Flew that way for over 50 years.

Built a new airplane about three years ago. Had it finished and started making the metal fuel tank which slides in from the front. Something is wrong! The fuel tank is going to be upside down! I had built a CW airplane without realizing it. OK, such is life. Set it up to fly with the up line on top. Very cautiously flew it several fights before doing anything radical. Eventually started practicing the Old Time Stunt pattern. Had to think about what I was doing instead of just doing it. Now, a couple of hundred flights later, I can fly the pattern almost as well as I can fly it going CC. Who says an Old Dog cannot relearn an old trick?

RE: Which way do they fly Down Under?
 

My NZ experience-in four clubs over the years-is there seems to be about equal numbers to L->R and R->L-but this seems to depend more on the site and the strip orientation towards prevailing wind and obstacles than any particular custom-and is largely determined at club level. For example-the Christchurch club (my current one) are definitely a R->L club, my old Dunedin club was either way, depending on the wind, and the Killermont Vegas Club which I am an associate of (down at Omarama where I run the FF World Cup events) is a mix of RL or LR, again depending on the wind, and the Oamaru club was usually-but not always R-L, because the strip was oriented towards the sea-and the sea breeze was usually on shore from mid morning onwards. And specially for Raymond-the water goes down the plughole in a clockwise direction.............

ChrisM
'ffkiwi'

RE: Which way do they fly Down Under?
 

Haven't you heard? We fly inverted down here, but it looks right way up to us because in the southern hemisphere our feet point up :)

RE: Which way do they fly Down Under?
 

Fellows, I don’t think it’s all that mysterious. It has to do with the fact that most of us are right handed. Thus, for example, when flying U/C we right-handers favor a CCW path since ‘whipping’ (to assist take-off and extend the glide) is easier. You are pulling with your arm and facing forward rather than using a back-hand and looking over your shoulder.
It may carryover to R/C since a left hand pattern results in a left turn to exit the pattern and a left turn to turn on final. Since the pattern is flown away from the pit area, that results in a left to right take-off and landing. I believe the left to right results from us right hinders favoring left turns.
There is more collaborating evidence that we tend to favor left turns. For centuries horses have always been mounted from the left; (thus pulling their head to the left); beginning motorcyclist usually find it easier to make left turns and note that the kick stands on bicycles and motorcycles are on the left.
I rest my case, but won’t be offended by sarcastic criticism:).

But, most importantly and possibly most overlooked in this thread IMO, is that we at last have a documented account from a creditable eye-witness that water in the southern hemisphere does in fact go clockwise down the plughole.
I was in college before I found out that coriolis wasn’t a grasshopper like insect[:o].
Thanks ffkiwi.
al

RE: Which way do they fly Down Under?
 

The anti clockwise direction (counter-clockwise for those in the northern hemisphere) seems to prevail in other areas too - look at NASCAR. Or speedway racing or any oval track racing including horses. Or pylon racing. Go fast and turn left. It just seems more natural. Can't explain why, just making an observation.

RE: Which way do they fly Down Under?
 

I think the Coriolis effect (it is only a fictitious force) is way too small to be of importance here. A plane would like to follow the air movements and they do display a Coriolis effect but only at a much larger length scale than the typical air-fields I have seen...

I fly counter clock wise because my planes have always tended to take of in that way...
So torque is important for RC at least.

Another thing is that clockwise is not that well defined. If you imaging yourself looking at the plane from above it is all reversed. ;)

RE: Which way do they fly Down Under?
 

Interesting question.

I might add to the discussion something further for thought - here in North America and some would argue in any civilized country, we drive our cars on the right side of the road while sitting in the left hand seat. Our tendency is to prefer left hand turns while driving and this has been noted by the civil authorities while tailing or chasing ummmm.. lets say suspects. However, civil authorities have noted in the less civilized countries where they insist on driving on the left side of the road (where the drivers seat is on the right side of the vehicle) that right hand turns are prefered and someone being chased with tend to turn right more often than left - at least that is what I was told.

I suspect perhaps, common aeronautical procedures aside, that we tend to have our brains wired to the "left hand turn" preference for a number of reasons the foremost perhaps is simply that is what we learned; traffic avoidance, wind direction, and obstacle location are secondary and tertiary but can and do frequently override our learned instinct as we adapt to our immediate needs.

cheers, Graham in Ottawa Canada

RE: Which way do they fly Down Under?
 

I've found that the cops on my tail can keep up with both left and right hand turns just the same, no matter how hard I try to lose them.

RE: Which way do they fly Down Under?
 

Maybe it's the tourque effect that makes us fly left.

RE: Which way do they fly Down Under?
 

Clockwise and counter-clockwise are ALWAYS defined as looking down from above the action being observed. Yeah, ok, propeller rotation as viewed from the front. Every club I've ever been to has the traffic pattern flying counter-clockwise. We may change direction of takeoff and landing (left to right or right to left) to accommodate the breeze, but once airborne, it's always counter-clockwise (as viewed from above).

I've only ever visited flying fields in the US, but have always suspected that south of the hemisphere the pattern is clockwise. I figure it has to do with the rotation of the earth, the Coriolis Effect, that affects ocean currents, air movement and yes, the water draining down a pipe.

RE: Which way do they fly Down Under?
 

Hey Ray, me thinks you have way too much free time! :)

RE: Which way do they fly Down Under?
 

I should have known that some of youse-all would come up with scatological humor but I didn't expect such a direct connection via the toilet (loo, or WC).

However (and thank you very much), I now have a mental image of a grown man standing over the primary porcelain fixture and marveling at the fact that your finest efforts always depart in the same direction. My hat's off to you.

For the rest of youse, thank you once again for reaffirming my faith in your collective wisdom and willingness to share.

RE: Which way do they fly Down Under?
 

i guess im the oddball, im left handed, so flying a right hand pattern feels better to me:eek:

RE: Which way do they fly Down Under?
 

right handed here...but can only high alpha knife edge from right to left down the runway.;)

RE: Which way do they fly Down Under?
 

If you think about I suppose that's logical. Does that mean that if you fly to Oz or NZ at some point, probably over the equator, the plane has to do half a roll to avoid landing upside down.

RE: Which way do they fly Down Under?
 

I've enjoyed reading the responses to flying Down Under. All this reminded me of the scientific definition of "UP", that being : any direction away from the earth ! So I believe we're all OK !

RE: Which way do they fly Down Under?
 

So is Ray pronounced Yor down there?[sm=bananahead.gif]

RE: Which way do they fly Down Under?
 

This is an interesting topic...

While I have always liked the idea of attributing drain vortex direction to the Coriolis effect (especially when it comes to telling my kids!), in practice this is most unlikely. In fact, simple experiments can prove this reasonably well.

The way to ascertain whether fluid motion is subject to the Coriolis effect, is through what's know as the Rossby number. This dimensionless number essentially tells us what the balance of forces are on a fluid. It can be written as:

Ro = U_h/fL

where Ro is the Rossby number, U is the velocity of the fluid (in principle its 3D vector but for simplicity we'll consider its horizontal component, U_h), f is the Coriolis parameter (a constant at any given latitude), and the length scale of the motion, L.

Without getting into details of how and why the Rossby number tells us whether Coriolis is important or not in a fluid flow, suffice it to say that when Ro is small (~< 1), then the Coriolis effect is important, when Ro is large (>1000), then it is not. As an example, in a tornado, Ro is of the order of several thousand. In contrast, oceanic large scale dynamics have Rossby numbers of the order of unity. It is because of this that it is important to factor in Coriolis forces in the forecasting of ocean dynamics. Likewise, it is also important in Rocket dynamics where the motion of a rocket is over very large scales which, when factored by the Coriolis frequency, f, may exceed the velocity by an order of magnitude or more (yielding small Ro).

On the other hand, if one considers a typical bathtub flow with U_h ~ 0.6 m/s, L ~ 1 m, and the bath taking place somewhere in upstate Vermont (~45 degrees latitude), then the Rossby number, Ro ~ 6000. Clearly, from this result it can be seen that the drain direction of tub water due to Coriolis forces is negligible. Further, at the equator, where f -> 0 (approaches zero), the Coriolis effect is nil (and Ro approaches infinity).

The length scale at which Coriolis (rotational effects) begins to become important is known as the Rossby radius of deformation, L_R. In large scale fluid bodies, one can calculate the Rossby radius to see whether Coriolis plays a role in the resultant dynamics. It is well understood that for viscous, slow moving fluids (e.g., water), the Rossby radius is of the order of several km meaning that rotational forces in water only become important in bodies of the scale of the Great Lakes. In the atmosphere, where air is less viscous and moves considerably faster, the Rossby radius is much larger and so Coriolis only starts to become important on planetary scales. Indeed, the various weather fronts (low pressure, high pressure), that we regularly see on the news forecast over continents, are in fact knows as planetary waves or Rossby waves.

Mr. Rossby (a Swede) was an important physical meteorologist and oceanographer of the last century. I was fortunate enough to enjoy his son's teachings (in Rhode Island) during my academic years.

Despite the above, while the kids find the idea of the spinning Earth being the cause of bathtub drain direction, I'll continue to encourage their spirited minds to ask questions... :)

David.

P.S. A related and other interesting phenomenon which is in principle more important to our flying is what is known as the Eötvös effect. This is the extension of the Coriolis effect into 3D space (U and fL are treated as tensors rather vectors) which results in models flying upward when heading East and downward when heading West. Unlike the Coriolis effect, the Eötvös effect is most important near or at the equator. But... good luck in noticing this effect on airplanes being flown in Ecuador or in the Sahara!

RE: Which way do they fly Down Under?
 

I concur with Vic's first reply.
Ralph

RE: Which way do they fly Down Under?
 

" Y O?R"

Silly Vic, they are used to being upside down - so it doesn't effect their brain. Sadly, the same can't always be said for 'upright' folks.

RE: Which way do they fly Down Under?
 

Upright or uptight? http://www.rcuniverse.com/forum/js/f...wink_smile.gif

Iagree with Doxilia however since he lost me in the first sentence Ihave no idea what he is talking about . http://www.rcuniverse.com/forum/js/f...ssed_smile.gif Ihave learned in my old age to nod my head and agree with the smart sounding guy.