Weightshift microlights are a development of the Hang Glider. The construction is similar to a Hang Glider, being built of aluminium tubing with a dacron covering. They are however built to be substantially stronger than Hang Gliders. They use purposely built wings with a "Trike" unit underneath to accommodate the pilot and passenger. The trike also houses the engine, instrumentation and forms the undercarriage. Control is achieved by moving the weight of the trike and its contents. Hence the term weightshift. Weightshift machines are also known as flexwings. Three axis microlights are more conventional in design. They are controlled by ailerons, elevators and a rudder operated by a joystick and pedals in the same way as light aircraft. Some three axis machines are built of composite materials such as fibreglass. Others are built from aluminium tubing with a dacron covering. The majority of aircraft in LMAC are of the weightshift variety.