I'd been using this to get 'roll':(A:Attitude Indicator Bank Degrees,degrees) /-/ (>L:Roll,number) However, it fails if the Attitude indiciator fails (or, there is no vacuum). I'd tried this before:(A:Plane Bank Degrees,degrees) /-/ (>L:Roll,number) (* 0.00 to -359.999 *) However, the angle is in the range of 0.00 to [-] 359.99... deg and does not go from -1.0 to +1.0 degrees as Bank changes from -1.0 to +1.0. I finally worked this out to give the 'Roll' angle I want:(A:Plane Bank Degrees,degrees) s0 180.0 > if{ l0 360.0 - s0 } l0 /-/ (>L:Roll,number) -180.0 to +180 deg, positive if rolling 'to the right'. These two are simpler, I only negated the A:variable value to get the values I wanted: (A:Plane Pitch Degrees,degrees) /-/ (>L:Pitch,number) (A:Incidence Beta,degrees) /-/ (>L:Beta,number) Finally, I found I had to use:(A:Relative Wind Velocity Body X,feet per second) (>L:Vx_fps,number)(A:Relative Wind Velocity Body Y,feet per second) (>L:Vy_fps,number)(A:Relative Wind Velocity Body Z,feet per second) (>L:Vz_fps,number) To get Vx, Vy, and Vz that depend only on AC 'wind velocities', with no effect from ambient winds. Those 'Relative ...' A: Parameters were not in the FS2002 Parmameters.doc. With correct Vx, Vy, and Vz components I can then calculate 'Yaw' and have no effect from ambient winds:(L:Vx_fps,number) (L:Vz_fps,number) atg2 /-/ rddg (>L:Yaw,number) This 'Yaw' appears identical to the 'Beta' (sideslip) above. However, I think there can be subtle differences between 'Yaw' and 'Beta'. Such as during a slip with near vertical wings. Ron

Ah nice, so I see (A:Relative Wind Velocity Body) was what you were looking for after all. I think I'm going to try those for the Velocity INS display to see why my wind components were off.--Jon

>Ah nice, so I see (A:Relative Wind Velocity Body) was what>you were looking for after all. I think I'm going to try those>for the Velocity INS display to see why my wind components>were off.>--Jon Thanks for suggesting that A: variable. I think the only way too figure out what all those sets of Velocity and Wind compenents do is to display them on a test window. I'm pretty sure there is a variable component to the ambient wind 'y' (up/down) direction. And, may well be vertical gust components. One could log the three ambient wind components, then analyse their frequency distribution. I suspect they follow a standard wind distribution. And, would bet they compare realistically to real turbulence. Ron