Licões Basicas 3D

3D with Mike McConville You've heard about these new 3D maneuvers, maybe even seen some spectacular demonstrations, but if you're like most modelers you really don't have a clue what they're all about. Well, read on and we'll try to help de-mystify the 3D "magic." So just what is 3D? In simplest terms, it's maneuvers performed by an airplane that are not done in a normal airplane flight path. Airplanes that hover; descend nose high at 45-degrees; float along in level flight, hanging on the prop; or tumble tail-over-nose in a rapid flipping motion. What makes a good 3D airplane? When you combine these maneuvers together with other loops, rolls, snaps and spins, it seems like the aerobatic options are endless. But you can't do this with just any old aircraft. In many forms of modeling, you can put an average plane in the hands of an excellent pilot and you'll see superb maneuvers. 3D isn't one of them. To fly 3D, you have to have a plane that's capable. What's capable? Well, it starts with having lots of pitch control. Elevators taking up 50% of horizontal stabilizer's surface is a start. (They need to move kind of like a barn door: 45º off neutral is good). The same control deflection applies, but to a lesser extent, with rudder and ailerons. Our choice for 3D is Hangar 9's CAP 232. It was designed with 3D aerobatics in mind, and we're here to say that, after a year in service, it's easily one of the best 3-D machines around right out of the box. It's great!

The Maneuvers

We'll cover the "How To's" of the 5 most popular 3D maneuvers:
 

• "the Blender"
• "the Elevator"
• "the Harrier"
• "the Waterfall"
• "the Torque Roll"

And with a little practice you too could master these maneuvers

The Elevator What it is: The plane drops vertically while in a nose-high attitude. Depending on head wind conditions, the model will drop at anywhere from about a 45º angle when it's calm, to vertical or even a little backwards in windy conditions. Throttle is used to determine rate of descent and the nose-high attitude of the model. CAP set-up: 3D-elevator mode is essential, and your CG will have to be on the mark or slightly aft. If your CG is further aft and the airplane teeters back and forth, program about 1/2" of up aileron with up elevator travel. How to do it: At near stall airspeed, up high, slowly feed in up elevator until you have the full 3D rate up in it. With low throttle, the CAP will fall like a rock. To guide it around, use the rudder, not ailerons. Just keep the wings level. Add power to change the plane's altitude. Trickiest part: Aside from steering it with the rudder, you'll quickly see that this maneuver is a matter of juggling the throttle and rudder to get the plane to go where you want it to go. Recovery: Basic- Add full power, flip off the 3D-rate elevator and fly out. Advanced- Take the elevator all the way to the ground, adding slight power before it touches down to slow the descent and transition into a "Harrier" and land. Or, for a little more drama, add power to get the nose to rise to vertical and transition into a Torque Roll. ("Elevator" from a hundred feet down to 20 feet then power up into a torque roll. Oh yeah!!) Worst way to mess up: Let your direction control (rudder) get away from you after starting too low- you could snap it right into the ground (ouch!).

The Harrier

What it is:

Very slow forward flight in a very nose high (about 45º) attitude.

CAP set-up:

The same as the elevator, and the raised ailerons help in this maneuver even more.

How to do it:

Start by entering an "Elevator". Let the model drop a little, then slowly add power until the vertical descent stops and it begins to fly forward with the nose very high- holding full up elevator (on 3D rate) all the while. Juggle the power to control the plane's attitude and forward speed. In a head wind, you may also have to juggle the elevator to keep the plane from rotating up to a vertical attitude. Use the rudder to steer the plane around in the Harrier attitude. Try to use the ailerons very little, as they will cause the plane to wobble side to side.

Trickiest Part:

Keeping up with the plane if it begins to wobble.

Recovery: Basic-

Simply add full power and reduce elevator to transition into normal forward flight. Advanced- after you get the hang of flying around in the Harrier, juggle the throttle to slowly lose altitude and do a Harrier landing. The plane will land on the rear of the rudder first, then add a little power so it doesn't smack the landing gear too hard

The Waterfall

What it is:

A continuous tail-over-nose descending flip. It's not a loop, but the aircraft actually flops around its canopy.

CAP set-up:

Once again, the critical component is having the 3D-elevator travel 4-1/2" of down elevator. An aft CG helps this the most.

How to do it:

Start relatively high. At low throttle, gradually pull the nose up until it's near vertical. Just before it stalls, add full down and full power at the same time. You have to continuously "fly" the rudder and ailerons to keep the plane flipping over in a straight line. To do consecutive Waterfalls, continue to hold full down and "fly" rudder and ailerons, and chop the throttle as the nose comes back up to vertical, then add full power as it flips straight down.

Trickiest part:

No doubt here- flying the rudder and aileron correctly. You really have to "fly" them and make constant corrections. The amount of rudder you add will vary. If you don't do this, the plane will fall off into a knife edge spin.

Recovery:

Just neutralize the elevator and the CAP will quit flipping, but expect some over-rotation, so practice high until you get the feel for it. Fly out straight and level, or stop the rotation while pointed vertical and go into a torque roll.

Worst way to mess up:

Take it down too low, over-control your elevator on recovery and snap into the ground. To avoid this, simply change rates on your elevator to normal 1" travel.

The Blender

What it is:

The Blender, or Panic maneuver is a vertical diving roll that virtually stops its descent as it instantaneously enters into a flat spin.

CAP set-up:

3D set-up as described in the manual. Most likely you'll have 60-75% expo with these settings. The CG should be on the mark or aft 1/2". Make sure your wing is strong-this can be an extremely violent, but always exciting maneuver.

How to do it:

Start from about 400-500 feet straight and level, chop throttle and push the nose straight down. As soon as the plane is diving straight down at low throttle, add full left aileron. Let it complete 2 or 3 rolls, then quickly transition the sticks to an inverted snap roll position (left aileron, right rudder, down elevator) all at the same time. If you do it right, the airplane will instantly transition from a left roll to a flat spin in the same direction, and the descent will all but stop. Add full throttle just after the spin goes flat making the rotation speed high and helping stop the vertical descent.

Recovery:

Simply release rudder and aileron, and hold just a little down elevator. The plane will stop rotating and begin to fly out. As it gains airspeed, roll back to upright. Remember you're in "3D mode," so don't do anything abrupt or you can stall the airplane.

The Torque Roll

What it is:

Plane "hovers" vertically in place, rotating left around its roll axis.

CAP set-up:

Full 3D throws in elevator and rudder are a must. An aft CG helps a little also. Some flyers will run their CG back to make this maneuver easier without gyros. But gyros provide the best aid to stabilize the aircraft- they won't do the maneuver for you, but they'll help. The pros will also tell you to add 3/4 degree of upthrust to your engine. This helps keep your CAP from falling forward in the Torque Roll, and it'll fly straighter uplines in non-3D maneuvers, too.
With a little aft CG, gyros and upthrust, you'll find your plane will be set-up best so you can concentrate on attitude recognition. Naturally, you'll need lots of power for this one: A Saito 150 is fine when propped with an APC 16x8. Heli 30% fuel is also a good option.

How to do it:

Fly low along the ground at low throttle, and gently add power with up elevator to bring the plane into a vertical position. Some flyers add a little left aileron to get the roll motion started. Add throttle to keep the nose pointed up and make corrections with rudder and elevator to keep things straight.

Trickiest part:

Recognizing your correction when the plane's belly is toward you. (Tip: Think push the rudder toward the low wing when the belly is toward you.) You have to be fast with throttle corrections. Most flyers add "bursts" of power, along with rudder/elevator corrections. If you simply hold full throttle, you'll climb out of the maneuver.

Recovery:

Fly out at full throttle.

Worst way to mess up:

An unreliable engine. Torque rolls are tough on engines because they're running at near-peak power with only prop-induced airflow over the head. Some flyers open up the CAP's lower exhaust hole for adequate cooling on hot days.

3D with Mike McConville Part 2