Differences between RC Helicopter and RC Airplane Flight

Any helicopter pilot who can hover can takeoff and land. With an airplane, taking off and landing is usually considered harder than straight and level flight.
When flying forward with a helicopter, you have to keep the nose down to keep flying forward.
Hovering a helicopter is a completely different process than hovering a 3-D airplane.
Airplanes generally need a larger area to fly in than helicopters.
When more than one person is flying an airplane at a field, they generally fly planes in a pattern around the runway. Helicopter pilots tend to choose their own zones in the air, which they stay in and do not leave.

Recent radio systems generally have modes for both airplanes and helicopters, but there are a few other differences. RC helicopter radios lack the ratchet that RC airplane radios have on the throttle. The ratchet is great for keeping the throttle setting constant on an RC airplane, but it is not good for helicopters because variations in the throttle setting smaller than the graduations on the ratchet may need to be made. RC helicopter radios also have a 3 position flight mode switch on the left side (normal, idle up 1, idle up 2) and a 2 position throttle hold switch on the right side.

Motors, engines, batteries, and ESCs are usually interchangeable between helicopters and airplanes. Motors that are specifically designed for helicopters use more oil in the fuel and have a larger heatsink.