Can somebody please explain me what table 400 (ground effect) in the air file is for and what the x and y values mean?I see that when all y values in this table are set to 0, the airplane has zero lift as well...Andreas

Table 400 varies the slope of tbl 404; so setting the y values to zero will result in exactly what you describe, the aircraft has no lift, since tbl 404 defines the coefficient of lift characteristics for the aircraft over the complete flight envelope. The X values correspond to altitude AGL/wingspan, the y values to coefficient of lift. Try monitoring one of the default aircraft with AFSD; use the autopilot to precisely control pitch and to allow you to watch the AFSD readouts, you