Just as the subject says but 3D as it relates to rc planes (not 3D King Kong movies).

-Mark

the engine dos more work than the wing

like

hovering

torque rolls

waterfalls

blenders

yo yo's done right

rolling harrer circles

that will give you the idea when your ready to do it ask and get a list of all of the moves

Hi CODEPUNK! Not much to add to PROPHANGERS answer except you need a plane with enough power to haul it straight up , with power to spare. A lot of guys fly with combos that go straight up at half throttle. A great way to get acquainted with 3D is to visit the MORRIS HOBBIES web site.

Three Dimentional... j/p

Actually, three dimensional.

3D flight is generally described as flying an aircraft beyond the point where the wing is in a "stalled" condition. In other words, the wing is no longer generating lift, and the aircraft is kept in the air by the "lift" created by the prop. And yes, a lot of power is required of the engine. A 3D capable plane will usually have a thrust to weight ratio of at least 2 to 1. (ie, a 10 pound plane would require an engine that generates at least 20 pounds of thrust.)
Dennis-

DBCherry is the closest... 3D aerobatics describes certain aerobatic moves that can only be performed in stalled and/or thrust vectored flight. However, I'd like to point out that the wing is still VERY important in 3D flight. A common assumption is that stalled wings don't generate lift. This is incorrect... stalled wings still generate lift. This stalled wing lift is critical for most 3D, such as harriers, elevators, parachutes, blenders, etc.

3D is lots of fun

Ok, that's makes a lot more sense. I have seen videos of these planes then. Looks like a lot of fun and I'm sure they turn a few heads. One of the videos was a plane. If it was in a hovering position, what makes it go forward or turn or do much of anything? Does the propeller actually pivot somehow? I guess this is what you're trying to say about their actually being lift during a hover. Conceptually I just don't see how since there isn't any airflow going across the wing surface (or is there?)

Thanks,
Mark

Ditto on what kenny said

There IS airflow, the prop wash from the prop.

For this reason, 3D planes typically have exagerated control surfaces so that they remain effective in just the prop wash. Also, 3D planes require the control surfaces to extend all the way to the fuselage. Wing-tip aileons would simply not work because they would be outside the prop-wash.

gus

While a stalled wing MAY still generate a very small amount of lift, it is inconsequential (not much more than propwash). Having the engine 'burp' is all it takes in most 3D manuevers for the plane to fall from the air, with little if any forward 'glide'. [:@]
Dennis-

Actually, how much lift a stalled wing generates depends on the airfoil. There are several airfoils out there that just kind of mush and slowly loose lift as AOA increases, with very little immediate drop in lift. There are also a number of airfoils where the lift basically falls off a cliff past a certain AOA. The later are real fun on landing approaches.

DBCherry, I haven't done any wing tunnel tests but I firmly believe from my experience that the wing in 3D is providing more lift than many assume. My primary 3D plane, a 35% Carden 540, only has 1.5:1 thrust to weight. I can harrier all day long at about 1/3 throttle, which on how I have my throttle curve setup, is nowhere close to 1:1. Probably closer to 0.5:1. I know this becasue I hover at about 3/4 throttle stick, which is 1:1. With smoke on (poor mans wind tunnel), I can see the airflow over the wing during a harrier. There is seperation, so I know the wing is stalled. It is possible that the AOA is not as high as one might first assume becasue the airflow over the wing, esp at the root, is influenced by the prop wash. But still, with only 0.5:1 thrust to weight and a AOA at the tips of say 30 degrees, most of the thrust is in the horizontal vecotor, which means less than have of the thrust is vertical. Assuming my throttle setting of 0.5:1, that means I still have 75% of the weight of the pane that must still be supported by something during a harrier. It has to be the wing.

Montauge is correct. In fact, with the airfoil and reynolds number I operate at, the transistion from normal to stalled flight is very smooth. I'm sure if my wing were tunnel tested, the knee of the curve where lift drops off at the stalled AOA must be very smooth, i.e. rounded and not abrupt. Some airfoils stall suddenly, thier lift drops very quickly past a certain AOA. Others then to be more gentle and the lift slowy diminishes past a certain AOA. Many airfoild can still generate 50% of the maximum lift at AOA's of 45 degrees! This is well past the stall point, which is typcially between 10 and 20 degrees, depending upon the airfoil. In general, thick airfoils with blunt leading edges tend to have very gentle stalls and generate lift well past the stall point. Thin airfoils with sharp leading edges tend to have abrupt stall point where lift is lost quickly past the stall point. Reynolds #'s (scale/velocity factor) also has a lot to do with how wings stall. It is my gut reaction that the larger 3D planes tend to stall more gently. This is why 3D in a 40 sized plane looks differnetly than 3D in a 40% plane.

Reguardless of the technical mumbo jumbo, 3D is a blast!

Add up all of the definitions deduct a few of them and multiply that by the fact that its the fastest growing form of R/C today and you have 3D

Finally, 3D is about doing something more with your free time than just flying around in circles with a mediocre plane!

John,
I'll have to defer to your experience. I've never flown 3D, but seen it often. I've also witnessed two fairly dramatic crashes that were, in both cases, caused by an engine that skipped a beat. (Low fuel in one case, not sure about the other.)

The one caused by low fuel was during a hover, which obviously rules out lift being generated. The other was during a slow rolling circle about fifteen feet off the ground, but the aircraft was upright and flying at about a 30 to 40 degree AoA at the time. Plane dropped pretty much vertically to the ground. [:@]
Dennis-

DB, I think I understand where you are coming from now after your examples. Hovers/TR are basically 100% enigne. The only thing the wing does in a hover/TR is prevent you from spinning like a top. And yes, If your engine dies, even in a harrier, you are probably hosed. But it is not becasue the engine is holding most of the plane up. It is becasue when flying at a high AOA, i.e., stalled, there is a LOT of drag. Without the engine forcing the high AOA wing thru the air, the plane will stop quickly and fall like a brick. If you lose an engine in a harrier, you need a fair amount of altitude to get nose down and build up airspeed such that the wing can fly unstalled again. On my 35%, I'd probably need at least 50 feet of altitude to fly out and land from a dead engine in a harrier. But I'm just guessing as I've never had an engine flame out on that plane. Anyway, from your examples, I can see how one could easily assume the wing isn't doing much.

When the plane has not much forward movement and is not in a strait and level path...everything that the pilots that ly around in circles dont do is what 3D is made up of

Dan