bool 
AirspaceWarningManager::UpdateGlide(const AircraftState &state,
                                    const GlidePolar &glide_polar)
{
  if (!glide_polar.IsValid())
    return false;

  const GeoPoint location_predicted = 
    state.GetPredictedState(prediction_time_glide).location;

  const AirspaceAircraftPerformance perf_glide(glide_polar);
  return UpdatePredicted(state, location_predicted,
                          perf_glide,
                          AirspaceWarning::WARNING_GLIDE, prediction_time_glide);
}