Aircraft Data Structure

struct AirData {
  double  Lat;    //aircraft's latitude
  double  Lng;    //aircraft's longitude
  double  Ht;     //height above sea-level (Earth Radians)
  double  GndHt;  //est ht of grd beneath aircraft
  double  Hdg;    //gnd-track hdg (compass + wind-drift angle)
  double  Des;    //aircraft's angle of descent 
  double  Spd;    //aircraft's true horizontal ground speed
  double  Pitch;  //aircraft's pitch angle
  double  Roll;   //aircraft's roll angle
  double  Rot;    //rate-of-turn in radians per second
  double  TD;     //diameter of aircraft's min turning circle
  int     Sw;     //Id of NAV rx switched to nav computer
} Air;