fgTie("/environment/turbulence/magnitude-norm", _environment,
&FGEnvironment::get_turbulence_magnitude_norm,
&FGEnvironment::set_turbulence_magnitude_norm);
fgTie("/environment/turbulence/magnitude-norm", _environment,
&FGEnvironment::get_turbulence_magnitude_norm,
&FGEnvironment::set_turbulence_magnitude_norm);