Tracking in round manuevers

After spending 4 days fighting the aerial wars at Brodak's Five Ring Circus, I have come to the realization (with the help of 4 score sheets) that the round manuevers are not as easy as I had thought.

Now that I am a bit more comfortable flying, I realize that I am constantly opening and closing the radius of a loop to try to make them round . This does not make for uniform, superimposed loops and eights.

I seem to remember planes in the past that would sort of just follow your hand around in a circle with out too much conscious effort to keep the loops round. Of course, in the past, I wasn't trying to keep the bottoms 5 feet off the ground, so that may be a factor.

Upon studying Paul Walker's Trimming Chart, he says the quality of the Track is a factor of the "prop,leadouts, elevator, nose/tail weight, engine, clean lines, sealed hinge lines, rudder adj, and tip weight". That pretty much covers everything.

Can anyone simplify this for me a bit?

Thanks,

Warren

Conditions:

Plane is a 110% Prowler.
Engine - Woolard OS 40 FP.
CG - would have to look up notes, but I think it is correct.
No engine offset.
Minimum rudder offset.
Hinge line sealing -(honest) only got the job half done. I'll finish it.
Control system is free and smooth.
Yaw - can see 1/2 a tire width in flight.
Level flight, upright and inverted is very good.

One thing that you forgot to say was the HANDLE. Handle spaceing is so important for the rounds that if you turn inside faster then outside your rounds will look big and then small. When doing the Rounds make sure that you don't go above 45 degrees because you will loose a little line tension. Horse power is so important. Lack of HP and you'll make egg shapes and mis your intersections. Brod props will help, wing tip weight, and fly with the handle IN FRONT of you, not off to the side. Look down the lines, follow plane. Hope this helps. Scott

>One thing that you forgot to
>say was the HANDLE.
>Handle spaceing is so important
>for the rounds that if

Scott....handle line spacing is at 4 inches. That's a comfortable sensitivity for me with this plane.

>fly with the handle IN
>FRONT of you, not off
>to the side. Look down
>the lines, follow plane. Hope
>this helps. Scott

Yesterday I got in 5-6 good practice flights, and I kept the hand position in mind. I made a conscious effort to keep my hand in front of me like you suggested, and I think it did help. Tracking was better. On the horizontal eight, a slight rotation of the body to stay perpendicular to the lines seemed to help.

For some reason, I find that my hand gets in positions opposite of where the plane is going. It's probably a combination of control input, and increasing or *easing* line tension. I'll try to work out of that habit.

Brett...

I WILL seal the hinges.

I'll experiment with CG.

Speed....I don't get much of a 4/2 break. I tend to stay in a rich 2 cycle most of the time as I get an improved 'tug' which gives me a more comfortable feeling of security.

I understand what you mean about arm rather that hand input to facilitate a smaller, controlled input. I'll work on that.

Thanks,

This was told to me by a friend as coming from George Aldrich. When flying the rounds, focus on the center of the loop, not the airplane. I really havn't tried it, but a couple of times the sun was in the center of a loop. I sort of focused on the sun, and my impression was that the airplane did beautiful loops. I guess I should really give it a try.

One thing I have noticed while judging is that loops 2 and 3 are often centered about 10 feet to the left of loop 1. I found that I do this myself and have worked at correcting it.

I find the horizontal 8's to be difficult to fly well. I've often seen intermediate flyers fly their square 8's better than their rounds.

I think this is a good idea. You concentrate on a point in space, and fly around it. This is what GMA advied me to do also.

I have noticed from both judging and flying, that non-flapped models seem to fly "facetted" rounds, while flapped models, regardless of how bad the shape and concentricity, did not. I suspect that the typically more novice class builder/flier may have the controls too sensetive, or perhaps the CG a tad too far aft for smoothness? Maybe the builder of flapped models pays more attention to the plans for control ratios, where the guy with the non-flapped design just puts it together so it looks about right. Is there some reason why a flapped model might just do the rounds more smoothly that I am missing? Steve

>
>Now that I am a bit
>more comfortable flying, I realize
>that I am constantly opening
>and closing the radius of
>a loop to try to
> make them round .
> This does not make
>for uniform, superimposed loops and
>eights.
>
>I seem to remember planes in
>the past that would sort
>of just follow your hand
>around in a circle with
>out too much conscious effort
>to keep the loops round.
>Plane is a 110% Prowler.
>Engine - Woolard OS 40 FP.
>
>CG - would have to look
>up notes, but I think
>it is correct.
>No engine offset.
>Minimum rudder offset.
>Hinge line sealing -(honest) only got
>the job half done.
>I'll finish it.
>Control system is free and smooth.
>
>Yaw - can see 1/2 a
>tire width in flight.
>Level flight, upright and inverted is
>very good.

Seal the hinge lines! But assuming this, the tracking in the rounds is pretty sensitive to the CG position. If the loops want to continually tighten up, and come out high, then move the CG forward. If they tend to open up and come out low, then move the CG aft. It only takes a tiny bit. I ahve used different prop nuts to change this, like an aluminum nut vs. steel. This is a detectable difference even on 60 planes.

The other thing that helps is good speed stability. It's less important on flapped planes, but having a constant airspeed all the way around certainly helps. This is one area where 4-2 break motors come up a little short unless they are adjusted exactly right.

Even if all is well, you do have to fly the entire loop. If you leave the controls in a constant position, it will not really be round. This is the only adjustment I think needs to be made with arm as opposed to wrist motion. Just a tiny arm movement will supply the necessary corrections, as long as everything else is OK.

>Even if all is well, you do have to fly the
>entire loop. If you leave the controls in a
>constant position, it will not really be
>round. This is the only adjustment I think
>needs to be made with arm as opposed to wrist
>motion. Just a tiny arm movement will supply
>the necessary corrections, as long as
>everything else is OK.
>
> Brett

Question, Brett:

I agree totally that we have to fly the entire maneuver. You can't get lax or lazy anywhere in the pattern.

However, we have been working on proper technique and following the plane through each and every maneuver with the hand. If, in the loops, you make these tiny adjustments with arm movenent and not wrist movement, wouldn't this result in your hand making an oval shape? It would seem that this could be counterproductive to technique and the effort to keep the shapes in perspective. Granted we are talking small changes in input, but using arm movement only to make the corrections would demand a greater amount of arm movement, thus making the track of the hand noticeably "unround".

Len: You lost me on your last post. Why would an arm motion, as opposed to a wrist motion, cause oval shapes? What you are trying to do is make adjustments. The arm provides the adjustment in a more user friendly way, for the same reason that we instuct a newbie to use the arm and not the wrist. There's more of a gear reduction in the arm vs. wrist.

I would think departures from precise circularity could be introduced with either wrist or arm, just as proper corrections could be.

Wouldn't the preference come down to personal choice? Just asking.

My reference is to what the hand is doing, not the plane. What we are trying to do is track the plane with the hand. We want to keep the arm in front of us and extended straight towards the plane. When the airplane does a loop, the hand should be making a circular motion and following the flight path of the plane.

Thus in loops, the hand will go in a circular motion with the arm extended towards the plane. In the squares, the hand will move in a smaller square right along with the plane. And in the eights the hand moves in the figure eight motion--two distinct circles side by side.

But if you are correcting input with arm motion rather than hand motion while trying to keep the loops perfectly round, it would seem that the hand will be making an oval shape while you are attempting to do the round loop with the plane. If the hand can follow the maneuver exactly, you tend to keep the maneuvers in perspective. If the hand does not follow the maneuver exactly (or worse, goes in a different direction) that's when things go astray.

I'd like to add my two cents worth on the value of proper CG location for flying consistent loops and rounds. Brett said it just right re tail heavy (tendency to come out high) and nose heavy (tending to come out low). What is implied but not said in that statement is that flying loops with a less than optimum CG requires more control input variation to achieve constant radii and consistent tracking. This is because of the "couple" between where lift is produced and where the weight acts...think center of lift and center of gravity. The farther apart these two physical locations are the more they will work against one another to change the radius of your loops. By having them close together (why the modern flapped ships use large tails and CGs in the vicinity of 25% of the average chord) there is very little change in control input required throughout the loop. This makes them much easier to fly round and in the same place.

Another factor to flying good loops that hasn't been addressed is the importance of making an aggressive entry to the loops so that the proper radius is established almost immediately. The natural tendency is to enter loops gradually because the are supposed to be "smooth". This is a big mistake and makes it impossible to make the first loop "round" (the entry radius is much larger than the final radius achieved well into the first loop) and also impossible for the subsequent loops to be both round and in the same place as the first (distorted) loop.

Experiment critically with CG location and make your entries to round maneuvers aggressive so that you immediately "lock" into the proper radius and it will stay there with little input from the pilot.