Opt whether to use Horizontal or Vertical Flight Path Angle.
| Member | Value | Description | 
|---|---|---|
| eSphericalFPAUnknown | -1 | Represents unsupported angle type. | 
| eSphericalFPAHorizontal | 0 | Use Horizontal Flight Path Angle. | 
| eSphericalFPAVertical | 1 | Use Vertical Flight Path Angle. | 





