Although flips seem easy, doing them correctly and smoothly can be quite challenging. Flips and tumbles are a critical element of many 3D maneuvers.
Start by very slowly flying the heli forward. Push forward or backward on the elevator as you smoothly and slowly reduce pitch. As the heli goes thorugh vertical (nose straight up or down), move the collective stick to center, or 0 degrees pitch. This will prevent the helicopter from traveling or moving during the flip. Slowly and smoothly add negative pitch until the heli is inverted, at which point you should move your collective stick to 1/4 (-5 degrees pitch). As the heli passes thorugh inverted and back to vertical, you will again need to reduce pitch back to center stick (0 degrees pitch). Continue to increase the collective to postive pitch as the model transitions back to the upright position.
Excerpted from Len Sabato’s article, “Inverted Flight, Flips and the Tailspin” in RC Helicopter How To’s, available at AirAgeStore.com.