After boarding six passengers for a river rafting trip the pilot lifted off the hillside helipad. While commencing to move forward he allowed main rotor torque to turn the helicopter to the left but found that full right pedal was insufficient to stop the rotation to the left. An attempt to achieve forward speed by use of the cyclic control was unsuccessful and after about four rotations the helicopter collided with the hillside, rolled over rearwards and came to rest inverted. Four of the passengers sustained minor injury.
