Passenger seat with tilting seat bottom

A passenger seat comprising:

• a frame for being attached to a floor of a vehicle;
• an upwardly-extending seat back carried by said frame;
• a seat bottom defining an upper surface for supporting a passenger;
• said seat back and seat bottom being movable independently of one another;
• means for allowing manipulation of said seat bottom, said manipulation means and seat bottom moving in response to body pressures applied by a passenger seated thereon, said seat bottom movable independently of said seat back such that a tilt angle of said upper surface may be effectively pivoted about at least two axes relative to said seat frame to achieve a selected orientation, while the overall height of said passenger above said floor remains substantially constant;
• and
• passenger-operable means for selectively fixing said seat pan assembly in said selected orientation relative to said frame.