A category defined by FAI, referring to objects whose relative density is heavier than air, which generally fly by dynamic lift and propulsion. HTA is divided into the following 8 classes: Class C: Aeroplanes Class E: Rotorcraft (Helicopter) Class G: Parachuting Class H: Jetlift Aircraft Class I: Human-Powered Aircraft Class N: Short Take-Off and Landing (STOL) Aircraft Class O: Hang Gliders Class R: Microlight I i