If a helicopter is hovering stationary relative to the ground, anything hanging from it is at 1G. If it is descending, the thing feels less than 1G while it is descending. if it is ascending or turning, the thing will feel an excess of 1G. So; yes, gravity will feel different in an aircraft in motion, not necessarily just a helicopter either.
as the helo lifts off, it is accelerating away from the ground at 1G+the acceleration it uses to lift off. Probably would rip a person's head off it it were the only connection to the helicopter.