RC Helicopter Flying Glossary Terms

3D (flying)
High performance flying, usually combining two maneuvers at once. For example, mixing a loop and a roll, to loop while rolling etc...
540 Stall
A high speed climb followed by a 540 degree Pirouette as the heli stops climbing. See Pirouette.
Autorotation
A maneuver to land in the case of engine failure; the momentum of the rotor blades can be just enough to slow the heli down just before landing
Bell and Hiller
A control system commonly used for r/c helicopters that allow the pitch of the blades to change depending on where they are in their rotation with the aid of paddles to take a substantial load off the control system. Bell is the co ntrol system that involves the swashplate and linkages to adjust the pitch and Hiller is the part that uses a flybar or paddle to make the cyclic more responsive.
Binding
A bad condition where the control ajustments can not move as far as the maximum servo travel. This puts extremely high torque on the servo constantly and can ruin a servo with time.
Brain Fade
A mental condition where the person flying the heli, suddenly forgets which way to move the controls, or which control to move at all. This can happen for no apparent reason, even when you think you're comfortable at flying.
Buddy Box
Two similar transmitters that are wired together with a "trainer cord." This is most useful when learning to fly -- it's the same as having dual controls. The instructor can take control by using the "trainer switch" on his transmitter
Collective (Variable Pitch)
Describes the control which adjusts the pitch of the rotor blades; causing the heli to ascend or descend without the need to change the rotor RPMs. This is usually the up and down movement of the left stick on the Tx. Having the ability to do this means you can use the momentum of the blades when spinning to do an autorotation if the engine dies and gives quicker response time as well.
Dialed In
The term used to describe when you're power / cyclic / tail rotor mixing is set up just right, so that when you add power / cyclic the mixing adds / removes tail rotor thrust to maintain the exact same heading without needing input from t he pilot. Usually, you must spend quite some time making the mixing more or less sensitive via trial and error, by rapidly adding and removing power / collective. All heading hold gyro's are already "dialed in" by nature, all that needs to be done is to adjust the sensitivity so the tail does not wag / act sluggish. All mechanical and non hh piezo gyro's will need to be dialed in manually by tweaking the mixing on the Tx. Heavy cyclic inputs also affect the torque on the helicopter and must be mixed w ith the tail if that is possible on the Tx you are using. Again, this is already taken care of with a heading hold gyro and only applies to standard mechanical and piezo gyros.
Flapping
A type of rotor head where the two rotor blades are not connected directly through the feathering shaft (a thick wire), each blade can move somewhat independently of the other resulting in smoother control of the helicopter and the to some degree the feel of a .60 size heli.
Ground Effect
Described as an increase of performance within 1/2 rotorspan of the ground. Which means, near the ground your blades produce more lift
Ground Resonance
This describes the phenomena that can make a helicopter shake itself to bits on the ground, even when it is perfectly balanced in the air. This is more common in seesaw type heads which aren't as dampened as flapping heads, and is also more common on pavement or hard surfaces which don't absorb vibrations.
Hovering
The process of flying, while not going anywhere
Nose-In
A term that describes hovering or maneuvering with the nose of the helicopter pointed at the person controlling it. This is a advanced step in the learning stages of flying a helicopter because both roll and yaw are backwards in relation t o the controller.
Relative Wind
The direction the wind his hitting the rotor blades taking in to consideration flapping and retreating blades
Retreating Blade Stall
A dangerous situation resulting when in fast flight where the blade that is flying towards the helicopters tail looses enough airspeed to generate lift. This can result in loosing control of the helicopter.
Settling with Power
A dangerous condition when descending from a hover where the helicopter's rotor blades enter their own down-wash. This can cause a crash if you don't recover soon enough. Note: This is not a fatal condition on model helicopters because they have such a huge power to weight ratio, however it can catch you off guard and it does require more time to stop descending if you're in this state. Describes the imprecision of a control system, meaning the controls can be "wiggled" without the servo's moving. Slop can make the helicopter more unpredictable and less responsive to control input.
Throtle Curve / Pitch Curve / Programmable Points
Somewhat like exponential in that you change the way the servos move as you move the stick. Usually you would have a different curve setting for each idle up mode. In idle up one you might have th e throttle at 100% when the left stick is full down, at 50% when it's in the middle, and back to 100% when the left stick is full up. This way you can fly upside down. Some radio's have more curve points than others, which means you could have parts of the stick less sensitive than others, so you could make it easier to hover gracefully on a machine with a very sensitive collective.
Throttle Hold
A feature that comes with many transmitter models. The opposite of Idle-Up, as in, this switch will keep the throttle at idle so that you can increase the collective without gaining high rpms / power. This switch can be used as a "s afety" switch while you carry your heli to the flight line, but is more commonly used to practice autorotations or if tail rotor control is lost causing the heli to pirouette rapidly opposite rotor blade direction, because when the engine is at idle, the tail rotors loose power so the heli will slow down it's pirouettes and you can autorotate to the ground in a more controlled manner. It is also advisable to hit this switch in the case of an emergency so that if the heli hit something it has no power bei ng applied to the rotor / tail blades.
Yaw Rate
A term that describes the control input of a heading hold type gyro. Instead of the rudder control adjusting strictly the tail pitch, as it does with a other gyro, a yaw rate gyro will uniformly control the rate at which the helicopter ya ws.
Yaw / Pitch / Roll
Terms that describe the change of attitude of a helicopter. Yaw is the movement about the vertical axis; Pitch describes leaning forward or backward; and roll describes leaning to the left or right (bank).

Ok, they all are some of rc helicopter glossary of terms, you can find more rc glossary in heliguy(http://www.heliguy.com/nexus/glossary.html). I hope the rc helicopter informations above will increase our knowledge. Thanks