The mailing list requires that you have an email account, and it helps if you have a bit of extra time, too. It's not unusual to get 100 messages per day! Your humble FAQ author created a second email account specifically for h-list mail, so it doesn't bury his regular email account.

To join the mailing list (aka "the h-list"), go to http://dmoz.org/www.uspilots.net/ and follow the 'mailing list maintenance' link to get signed up. Also, don't forget how to unsubscribe! Someday you'll want to.

If you ask a question on the mailing list, you'll typically get at least 4-5 responses over the next day or two.

The newsgroup requires newsreading software like Netscape Communicator or Outlook Express. Simple go to the rec.models.rc.helicopter newsgroup.

The newsgroup is slowest of the three media, but you will still have your answers within a couple days in most cases.

However, it can offer a few ideas that will hopefully make your decisions a little bit easier.

This document and the content herein are the opinions of the author(s), and they are entitled to them. Nobody else is responsible for those opinions. Nobody else is liable for those opinions. Nobody else endorses those opinions.

First, no matter which helicopter you buy these days, if you build it according to the instructions, it will serve you well. Each design has its own strengths and weaknesses, it's own die-hard fans and detractors. The most important differences have less to do with the helicopters themselves than your own situation. Ask yourself a few questions...

What do other people fly in your area?

Find out where other people fly in your area, and seek their advice. They will almost certainly be very helpful when you're starting out, and it's a good idea to start out with a helicopter that they are familiar with. That way, they will be better able to help you build, set up, and fly your new helicopter. They will be familiar with the shortcomings of your new helicopter (every helicopter has one or two) and they will be able to show you how to work around them.

What spare parts are available in your area?

If there is a local hobby shop that carries a good selection of spares for one or more models, this should affect your decision. Sooner or later, you will need spare parts, and the easier they are to obtain, the sooner you'll be flying again.

How much money do you want (or can you afford) to spend?

Most radios on the market at the time of this writing fall into one of three categories, as follows. The prices are of course approximate.

1. six channel, $250, entry level
2. eight channel, $500, mid-level
3. nine or ten channel, $1000, high-level

The entry level radios will provide enough functionality to allow for hovering, forward flight, and mild (airplane-style) aerobatics. If or when you get into advanced (or "3D") aerobatics, you will probably find yourself requiring finer control of the pitch and throttle curves, as well as programmable mixing and possible extra channels to control the gyro and perhaps governor.

The mid-level radios provide everything the average flyer needs - and almost everything the "extreme" flyer wants. They include very flexible pitch and throttle curves, a couple of programmable mixes (for example, to add throttle during tumbles), and extra channels to control gyro or governor settings.

The high-level radios include pretty much everything a person could want, and then some. They include even more flexible curves (for example, seven adjustable points per curves instead of three or five), more programmable mixes (would you like the governor to turn on automatically when you enter idle-up?), more channels for control of onboard electronics (in-flight adjustable mixture, governor speed settings, and so on).

If the thought of building the kit worries you, then RC helicopters are not for you - rebuilding these things is just as much a part of the experience as buying fuel and shooting the breeze with other heli flyers in between flights.

As you build the kit, you will learn a great deal about how the helicopter works. The more you know about how it works, the better you will be able to make it work just the way you want it to. The less you know about how it works, the more trouble you will have making it work at all.

At some point, you will crash it. If you built it yourself, you will look at the wrecked helicoper, frown, identify the bent parts, remove them, buy new ones, install them, and fly again the following weekend.

Though they may cost $200 or more, a simulator will - without question - save you at least $200 in crash repair costs because it will let you do most of your crashes in the comfort and safety of an imaginary world. Really, it's worth it.

When a new flyer arrives at the field for his first day, you can always tell whether or not they have been practicing with a simulator. If they spend their first 5 weeks skipping along the ground, stopping, carrying the helicopter back to the center of the flying area, making four-inch-high skips off in another direction, and so on, they haven't had the luxury of getting through this phase of the learning curve over the course of a few evenings at home. If they spend 10 seconds skipping around, then lift into an eye-level hover for the rest of their fuel tank, they definitely have a simulator at home. Really, the difference is that dramatic.

Your humble FAQ author learned with the help of a simulator, and had no idea how lucky he was until he saw how much time and effort it took to learn the old-fashioned way.

Before you take your first flight, you should have the helicopter examined by an experienced flyer. There are many, many, many ways to connect all of the parts, and not very many of them will result in a flyable helicopter. An experienced flyer will be able to wiggle the control sticks and see whether or not the rotor blades and carburetor bits are moving as they should.

If you want to find pilots (and you certainly do!), you start by finding out where they fly. If you already know of a local field, you know where to find local pilots. If you don't know of any flying fields near you, find them! Look in phone books, magazines, etc for local hobby stores. Ask the people at the store where their customers go to fly airplanes or helicopters.

If you're polite, you'll most likely find that people who fly helicopters are more than happy to answer questions, show you their equipment, and so on. There just aren't enough of us that we can afford to be rude to newcomers! Ask questions, and take note of the answers.

Note, though, that it's a really bad idea to talk to or even approach someone while they are flying a model. It takes enourmous concentration, and a tap on the shoulder or unexpected "Hi there!" can be exceptionally nerve-wracking. Causing someone to crash their model is a widely recognized way not to make friends.

The right stick controls the helicopter's orientation on the pitch and roll axes. It's easiest to understand if you picture a little helicopter perched on top of the stick... If you push the stick forward, the nose dips down and the tail comes up, as if you were transitioning from a hover to forward flight. If you pull the stick backward, the nose goes up and the tail goes down, as if you were entering a loop. If you move the stick from side to side, the helicopter will roll from side to side.

Moving the left stick from side to side controls the helicopter's orientation about the yaw axis - like steering a car. If you move the stick to the left, the nose of the helicopter moves to the left, for a left turn; if you move the stick to the right, the nose of the helicopter moves to the right, for a right turn.

It is a common mistake for a newcomer to set up the left stick in the opposite fashion, so the tail moves in the same direction as the stick. This is not recommended! Nobody else will be able to fly your helicopter. Sometimes, when you're having trouble with your helicopter, it helps to have someone else fly it and experience it for themselves. A backwards setup will prevent others from giving you the assistance they would otherwise gladly offer.

Dual Rates
The dual rate switches let you choose how sensitive the control sticks are. Typically, "high rates" are used for aerobatics, which require a faster tumbles or pirouettes, and "low rates" are used for hovering, where slower, softer responses will give more precise control and smoother performance.

Gyro Rate / Gyro Mode
The gyro switch will affect the amount and type of feedback the gyro provides to help keep the helicopter stable about the yaw axis. In the past, it was common to use a high gyro rate for hovering, and a lower gyro rate for forward flight and aerobatics. With modern 'heading hold' gyros, the switch usually toggles between 'standard' gyro feedback and 'heading hold' gyro feedback. While heading hold is usually preferred for most types of flying, standard mode will allow the helicopter to "weathervane" a bit, which can be helpful in fast forward flight and rolling maneuvers.

Throttle Hold
This is for "autorotation," landing with the engine disengaged. This switch brings the engine to an idle and may select a special pitch curve, while leaving all other controls functioning normally. Most people select a pitch curve with about -4 degrees at the bottom and +10 degrees at the top, though some prefer a symmetrical curve like +/- 9 or 10 degrees for aerobatic (rolling or tumbling) autorotations.

Idle-Up
The name of this switch comes from days of old when all it really did was raise your idle setting. Today, it would be better labeled the "flight mode" switch. It selects between different pitch and throttle curves for hovering and aerobatic flight. Every flyer has their own preferences for flight modes - the following are merely one example of how things might be arranged.

In "normal mode," low stick will bring the engine to an idle and will put about -1 or -2 degrees of pitch in the main rotor. Half-stick will bring the engine and rotor to hover settings, perhaps 60% throttle and 4 or 5 degrees of pitch. With the stick all the way up, the engine will go to 100% throttle and the main rotor will have 8 to 10 degrees of pitch.

In "idle-up-1" the throttle curve begins to look take on a "V" shape, which helps keep the head speed up during descents and mild aerobatics like loops and rolls. Low stick might provide -4 degrees of pitch and 60% throttle, quarter stick -1 degrees and 30% throttle, half stick +2 degrees and 40% throttle, three-quarter stick +5 degrees and 60% throttle, and full stick +8 degrees and 100% throttle.

Some people suggest taking this all in order. In real life, you pretty much HAVE to do them in order because if you can't hover, you can't take off or land without killing your helicopter or your spectators. In the sim you can do anything safely!

Work on hovering, and when that gets frustrating, work on flying around. When that gets frustrating, work on hovering some more. Switch back and forth all you want, or just focus on one thing until you have it down. Just do whatever it takes to keep it interesting, so you stay motivated.

Your humble FAQ author mostly learned hovering and forward flight at about the same time in the sim. Then, in real life, it was almost like starting over and things went in roughly the following order:

This is NOT necessarily the best order, but things just happened that way. I have a web page about this experience, you might find it amusing:

In the sim, I'd take off tail-in, whip around to nose-in and hold that as long as I could. I remember trying side-on at this time and concluding that it was harder than nose-in or tail-in, so I'd just clench my jaw until the heli came around.

In 'real life,' I learned figure-eights (up high, forward flight) before learning nose-in, so that did give me some side-on experience. I would do a couple figure-eights, and then continue turning (and slow down) until the heli was hovering nose-in about 25 feet up and 50 feet out. I'd hold that for a couple seconds, then whip the tail around and fly away. Over time, a couple seconds became a couple minutes, and by then I was pretty comfortable nose-in.

For some reason, side-on in forward flight has always been easier than side-on in a hover, so this approach worked pretty well for me.

I fly with a fellow who put his training gear back on when he started to learn nose-in. With the gear on, he started out nose-in on the ground, lifted off, and hovered nose-in for as long as he could. He intermixed this with some regular tail-in flying and small circles and circuits to avoid getting in too much of a rut, and it worked well for him.

That page was key to your humble FAQ author's first autorotations. There are just a few things I would like to add:

I did my first approaches in normal mode, which I had set up so that low stick gave me about -3 degrees of pitch and a nice idle. I practiced descending this way to get used to the sound, the head speed, the rate of approach, and so on. When the helicopter got down to 30 feet or so, I slowly raised the left stick, which reapplied power and allowed me to level out and fly on smoothly.

When I was comfortable with that, I started using the throttle hold switch. I would descend at low stick (again, about -3 degrees), flare, and turn off throttle hold so I could fly away safely. I did this several times, each time flaring a bit lower. There came a time when I figured I was almost ready to land, I would just flare at 3-5 feet a couple times and then finally I'd (gasp!) do it for real. As it happened, I descended planning to flare and 3 feet, and I just landed it instead. Everyone is always surprised at how easy it is after landing their first auto, and I was no exception.

Now go back and read HeliBuf's page once more, and have at it.

If the gyro direction is set wrong, the gyro will not act to reduce heading changes, instead it will act to amplify heading changes. The slightest touch of the rudder will cause the gyro to rapidly apply full rudder in that direction.

Helicopters are hard enough to fly without a gyro helping you. They're pretty much impossible to fly with the gyro fighting you every step of the way.

But it's better to be able to detect this condition before unleashing a five-foot flying lawnmower upon yourself and your neighbors. Fortunately, it's not too difficult.

Remove the canopy, turn on your transmitter and helicopter, and wait for the gyro to 'wake up' if necessary. For this test, the gyro should be in standard (not heading hold) mode.

That said, consider the following potential problems, roughly in order of likelihood:

This list is not complete, but it should get you started, and will address the most common "gyro" problems.

If you have no luck, consider the gyro itself - see if you can try a different gyro, preferably of the same make and model. Try changing servos, too.

First, and easiest, inspect your control throws. Reducing your throws will allow for softer response and slower rolls. Increasing them will speed up your rolls and make the controls more sensitive, but be careful not to bind the swashplate by trying to tilt it too far!

Second, and also free of charge: if you have flybar weights installed, move them closer to the rotor head or remove them entirely for faster rolls. Move them outward for slower rolls and a more stable hover.

Third, and also free if your helicopter allows it, change your Bell:Hiller mixing to allow more Bell input (direct from the swashplate) and less Hiller input (from the flybar) for faster rolls. Adjusting for more Hiller input will give you slower rolls and more stability.

Though it may seem counter-intuitive at first, the flybar actually slows down your rolls, so reducing the flybar's leverage on the main blades will speed up your roll rate. On many helicopters, this is adjustable via mixing levers attached to the blade grips. On others, it requires an upgrade part (the Concept series, for example, requires an aftermarket adjustable flybar seesaw). On others, it requres creativity... the Futura SE, for example, has non-adjustable Bell:Hiller mixing, at a ratio of 1:1. At least one Futura has been spotted with XCell adjustable mixing levers installed. Your humble FAQ author has a set of these levers for his own Futura SE, but hasn't yet gotten around to installing them yet.

Fourth, and usually fairly inexpensive, try new flybar paddles. Lighter paddles will speed up the roll rate; heavier paddles will slow down the roll rate.

Fifth, and most expensive, try new rotor blades. Different airfoils will affect your roll rate, as will different lengths. "Reflex" or "S-curve" airfoils tend to be more responsive, but more twitchy in a hover (this includes collective response as well as cyclic). Traditional airfoils are more stable.

For more information, check out this web site, which includes a nice diagram to explain how they work.

A standard fuel tank setup will have a two pieces of tubing connected. First, a simple "pressure" line, which attaches to a fitting at the top of the tank and typically connects to the muffler (which supply pressure). Second, an "intake" line, which connects to the carburetor at one end, and which terminates in the middle of the tank, with a klunk. The klunk is typically a brass weight with a hole drilled through the center - it attaches to the end of the fuel line and helps keep the end of the fuel line submerged, so the fuel line doesn't end up sucking air into the carburetor.

A uniflow tank will have three pieces of tubing connected. The old "pressure" line is now a "vent" line. It remains attached to the fitting at the top of the tank, but instead of going to the muffler, it ends in open air, with a valve or plug to keep the line sealed. In flight, it remains sealed - it is unsealed only to allow air to escape when filling the tank with fuel. The "intake" line remains unchanged. The third line is the new "pressure" line. One end is connected to the muffler (as before) and the other end is in the middle of the tank, with a klunk on it.

The klunk on the pressure line does the same thing as the klunk on the intake line - it keeps the end of the line submerged, even as the fuel sloshes around during loops and rolls and such.

A conventional tank will often cause the mixture to "lean out" as the tank empties. This is because when the tank is full, the fuel naturally "wants" to siphon out into the carburetor. As the fuel level goes down, the carburetor may actually need to "suck" to draw fuel up into the engine. The fuel pressure changes, but since the carburetor's suction does not change, the mixture ends up changing instead. Uniflow tanks cure this problem.

Conventional tanks are also sometimes subject to mixture changes between upright and inverted flight. Uniflow does not solve this problem entirely, but it can improve things enough to make some people swear by it in some of their helicopters (your humble FAQ author included).

Check back again for a link to a site with a good uniflow diagram to help explain how to set up a uniflow tank and how uniflow works to ensure a more consistent fuel/air mixture.

There is no free lunch, however... uniflow has a couple of disadvantages.

First, fueling becomes a little bit more tedious, as you must remember to open the vent line before filling the tank - otherwise you end up pumping fuel into the tank (through the intake line) across the tank (which cannot vent air or expand to accomodate the additional fuel) out of the tank (via the pressure line, which is submerged), and into the muffler. The amount of fuel that can pool up in your muffler before you realize what you've done can be embarassing.

Second, during an abrupt transition from high throttle settings to idle (e.g. practicing autorotations), uniflow can cause the mixture to become rich for a moment before the excess pressure is exhausted. Depending on the engine, helicopter, fuel, altitude, humidity, phase of moon, etc, this can actually be severe enough to cause the engine to quit! Before practicing full autorotations with a new uniflow setup, it's wise to practice a couple of small ones (from a waist-high hover) first to find out if this is going to present a problem.

Personally, I have found uniflow to be VERY effective in my Concept 30 SRX and OS 32sx, using both a muffler and a tuned pipe. I have personally never had the aforementioned throttle-hold problem, but perhaps I'm just lucky?

It's worth noting as well that high-pressure systems suchs as modern YS engines do NOT require uniflow to obtain a consistent mixture. These engines use crankcase pressure instead of muffler pressure, and use internal regulators to keep the mixture consistent.

You can find the CG by lifting the helicopter by the blade grips or by the inside ends of the flybar. If the tips of the skids leave the ground first, your helicopter is tail-heavy (this is not good). If the tails of the skids lift off first, your helicopter is nose-heavy (this is better). If the skids remain level, your helicopter's CG is right under the mainshaft (how much fuel is in the tank and what will happen when that changes?).

Your humble FAQ author's helicopters have foward-mounted fuel tanks, and he prefers to set them up so that when thet tanki s empty, the CG is directly under (or just barely forward of) the main shaft; with a full tank, the CG moves a bit forward of the main shaft.

Any flying object will have a tendency to orient itself so that the CG leads the aerodynamic center (also called the center of pressure, or CP). On most helicopters, the tail rotor and tail fins act to place the CP well aft of the main shaft, so if the CG is located forward of the main shaft, your helicopter will tend to "weathervane" into a nose-first orientation.

When you are learning, this nose-first tendency will be helpful, especially during autorotations. Should you progress into backward and sideways flight, or backward autorotations, you will be better served by a more neutral CG/CP relationship. (Hence the popularity of "skeletal" or even nonexistent tail fins.)

Note that aerodynamic tendencies are only part of the picture. With a heading hold gyro and a reasonable main rotor setup (i.e. anything but massive and feather-light flybar paddles), the helicopter will maintain whatever attitude the pilot commands, regardless of the helicopter's CG and CP. With a driven tail, the helicopter will maintain whatever attitude the pilot commands, even during an autorotation. At worst, an uncooperative CG/CP relationship will mostly show itself in decreased rotor energy as the tail fights against the weathervane effect.

For example, it seems that whenever someone buys a new kit, they always want to know what isn't in the instructions! Try as they might, manufacturers always omit a few details that can make construction and setup a little bit easier.

With lots of negative pitch and lots of cyclic, it's possible to throw the washout levers too far and bind them. This will result immediately strip out your cyclic servos (as the rocks back and forth at 1700 RPM), and catastrophe is sure to follow.

For a little extra safety, replace two of the balls on the upper/inner swashplate ring. The balls they instruct you to use have a 2 or 3mm standoff - replace them with the shorter no-standoff balls. I think you can scrounge them from elsewhere in the kit, but I'm not certain. I bought mine used and the previous owner already took care of it.

The balls that connect to the links that go up toward the blade grips can remain stock. The balls that connect to the washout lever should be shortened. This will give you slightly less input to the flybar, but you will still have enough to hit the limits on the rotor head. I assure you it flies well this way. I have yet to see a Futura in my area that hasn't been modified like this, in fact.

You will still need to be careful when setting up your radio - make sure that when you give full down collective and full cyclic, the washout levers aren't able to over-extend and bind. If you keep the bell links short, you can basically move the swashplate up on the main shaft while keeping the same amount of negative pitch. This keeps the washout happy.

The way my heli is set up, binding is impossible in flight. I never worry about it anymore.

Robbe produces an upgrade package to address this (part number S1025). The upgrade is relatively inexpensive and worth a look if you can't get the pitch range you want without risking your safety.

Three things to watch during construction:

Take care when tighening the bolts that hold the engine mount to the chassis. They hold the engine mount in place vertically, and determines the drive belt alignment. It's really no trouble to get it right, but if you overlook it you might have a surprise auto and a big wad of steel wool where the drive belt should be. Boy did I feel silly. :)

There's one thing that might be my fault and might be the kit, I'm not sure which. Build the rudder linkage before installing the tail boom. Line up the rudder linkage at each end as you slide boom into the mounting block. I pushed the boom in too far, now I can't back it out(!), and it's affected my rudder linkage geometry. Probably my fault, but keep an eye out for it.

The tail rotor's "flybar" must be able to tilt freely.

The metal block set-screwed to the end of the rudder control rod must be installed with the set-screw facing down, or your will face uncontrollable pirouettes as the gyro amplifies yawing motions instead of reducing them.

If you have significantly more rudder authority to one side than the other, you can adjust the pitch of the flybar paddles to bring things into balance.

Your rudder servo must exercise the entire travel of the tail rotor pitch change mechanism.