For your trial flight, remember this:
An aeroplane is dynamically stable, and wants to fly. It will only crash if the pilot makes it crash.
A helicopter is dynamically unstable, and wants to crash. It will only fly if the pilot makes it fly.
The differences you will see are:
1. You set an attitude, and you have to work to keep it there - no effective trim, and it wants to diverge.
2. Attitude is airspeed, power is rate of descent (or climb, or level)
3. Rotor is kept at 100% by the governor and throttle. Pull in power, the revs want to droop, governor or pilot adds throttle to keep revs up, MAP goes up.
4. Almost no feel to the cyclic stick (depending on R22, H300, B47) so it is really easy to overcontrol.
5. DON'T LET IT GO!
6. In forward flight, pedals control balance (skid ball / piece of string) but in the hover, balance is irrelevant, and pedals control where you are pointing.
You will start your flight with the instructor taking off into forward flight, and you following through lightly. Once airborne, he will get you to control the cyclic to hold the attitude / airspeed steady, then try some gentle turns, speed changes etc.
Next is the collective on its own, making some power changes. Then the pedals, keeping in balance while he changes the power. Then collective and pedals together, then all three. He will take over when you lose it.
Back into the circuit for some hovering, starting with pedals to make the nose point at some object; then collective, to hold height steady, then collective and pedals together.
Second last is cyclic, and don't be too upset when you lose it within 5 seconds. The aim is just to hold the attitude steady - don't worry about ground position, it will follow eventually. If you can correct a wrong attitude and get back to a level attitude, you have grasped the basics of hovering. Lastly, he gives you the lot in the hover, and you will lose it fairly quickly.
But you will find that flying a helicopter is the most fun you can have with your clothes on.
