This specification covers design and performance requirements that apply for the manufacture of lighter-than-air light sport aircraft. Performance requirements for balloons, airships and thermal airships are: proof of compliance; general performance; flight performance; climb; controllability and maneuverability; descent; landing; and stability and control. Structure requirements for airships, thermal airships, balloons and vectored thrust balloons are presented in details. The power plant installation shall be easily accessible for inspection and maintenance. The equipments for airships and free balloons are presented in details. The operating limitations and other information necessary for safe operation shall be established and documented in a flight manual, which will be made available to the pilot upon aircraft delivery.