I've found that using a simulator allows me to develop some of my flying skills without the expense of crashing a perfectly good airplane. There are a number of good PC-based simulators for R/C airplanes and helicopters. They range from the free Flying Model Simulator (FMS) to the more expensive Real Flight G2 simulator. I downloaded the FMS simulator to see if it would really help develop my helicopter skills and to compare against a friend's RealFlight G2 simulator. I've found FMS to be adequate for my needs, although G2's simulation seems to be more realistic.
Neither simulator I've tried accurately simulates the side-slip that a helicopter will experience just as it lifts off. The side-slip is due to the side thrust of the tail rotor hitting the down-thrust of the main rotor. The result is that a tail rotor that is mounted on the right side of the tail (looking forward over the heli) will cause the heli to slip to the left just as it lifts off. After the heli is about 1/2 a rotor diameter in the air, the side thrust effect disappears.
Another interesting effect of a simulator is that when the model flies above the horizon, you lose perspective with regard to how high the model is. It takes a while to memorize the look of some of the clouds that are typically in the simulations and gain an orientation within the simulation. In real life, we normally have enough peripheral vision to know where we are relative to the horizon and objects. It helps to try to fly so that the horizon is still within view until you memorize the surroundings.
FMS is free for download over the internet from http://simulator.home.pages.de. It is currently just over 6M bytes in size. I like its installation because it only relies on having DirectX7.1 or later. It doesn't mess with any of the Windows operating system files.
The basic helicopter types in FMS are much too stable to learn the light touch that's required for flying a House Fly or Piccolo. However, someone developed a model of the Piccolo which much more accurately models the real Piccolo. It isn't entirely accurate, but it is sufficient to gain the skills needed to fly the Piccolo. The Piccolo model is available from HeliHobby's Download page.
If you're learning how to fly airplanes, there is a slow-flyer that is much like some of the very slow electric airplanes. Once you get the hang of it, switch up to a higher performing airplane and hone your skills.
FMS can use either a keyboard or an R/C transmitter interfaced from its buddy-box connection to either a COM port or a parallel (LPT) port on your Windows-based PC. I researched radio interfaces and selected a JR computer interface (PDF) that is a bit more complex than the simplest, but is also more reliable. It takes a few simple components that are readily available from sources like Radio Shack and is easy to build. It is by Graham Collins. The directions say that it is for the FlyRC program (see below), but it will also work for FMS. The interface for other radio types will require a different plug for the buddy-box connection on your transmitter.
The FMS web site has a forum on which a number of radio interfaces are described. The best one I found was one titled "Bombproof circuit for JR XF631. The author took the time to explain how the circuit works.
If your computer is running Windows XP or Windows 2000, there is an
inexpensive alternative interface that may work (I've seenit
work on one machine and not on another). It is a software package
that allow you to interface your Tx through the microphone port on
your PC. It is available at
http://www.interq.or.jp/japan/cyber/fms/SmartP_e/SmartPropo_Manual_e.html.
FlyRC is another free simulator, but it doesn't include helicopters, which was one of my needs. It is available from its author, Ron, at http://www.pivot.net/~acarr/ron/ron.htm. One of the useful tools this package includes is a test program, Txtest.exe, that allows you to view your R/C transmitter's signals as the computer reads them. This tool helps when you build an interface and want to see what the computer is reading if the interface doesn't work. I used it to test the R/C radio interface that I built to use with FMS.
Real Flight G2 is the premier simulator on the market. It costs around $200-250, depending on your source. It is a very accurate simulator - much better than FMS. Info on it is available at http://www.realflight.com/. There are add-ons for the Piccolo helicopter for it, available on HeliHobby's Download page.
It now comes with its own dedicated joysitick box that is much like an R/C transmitter with dual sticks. It interfaces to your computer through a USB link. The joystick also includes an interface for your regular R/C transmitter's buddy-box connection.
One of the really nice things about G2 is that it has a virtual flight instructor who will give you advice about your flying during your practice flights. That's better than trying to figure out for yourself what you could be doing better to improve your skills.