To improve lift power consumption, ride quality, ability to fit rough guideway specifications and short radius curves, Societe de l'AEROTRAIN and BERTIN & CO. had to develop pneumatic air cushion suspensions. The use of flexible lips bearing pannels is a common basic principle of these suspensions. Canvas arrangement and difference of pressure across the pannel governs its equilibrium; a point to point relationship is obtained between cushion load and suspension height. Theoretical and test results found on an articulated pannel version of these suspensions, the K - K sub B air cushion, are commented. A set of computer programs provides estimates of static and dynamic behaviour of K and K sub B suspensions. Agreement between theory and experiments is good enough such that the model may be used to improve the behaviour of existing cushions of prototypes and to design new cushion for future Aerotrain projects. Also improvements of the dynamic model are or progress to find how to avoid critical instabilities and to get best damping on fundamental modes. This will help us to get better performance of Aerotrain ride quality which is already of the best among transportation systems.