diff --git a/src/Environment/ridge_lift.cxx b/src/Environment/ridge_lift.cxx
index f30a37400..0edbe2e85 100644
--- a/src/Environment/ridge_lift.cxx
+++ b/src/Environment/ridge_lift.cxx
@@ -32,14 +32,27 @@
 
 #include <Main/fg_props.hxx>
 #include <Main/globals.hxx>
+#include <Main/util.hxx>
 #include <Scenery/scenery.hxx>
 #include <string>
 #include <math.h>
 
+
 using std::string;
 
 #include "ridge_lift.hxx"
 
+static string CreateIndexedPropertyName(string Property, int index)
+{
+	std::stringstream str;
+	str << index;
+	string tmp;
+	str >> tmp;
+	return Property + "[" + tmp + "]";
+}
+
+static const	double BOUNDARY1_m = 40.0;
+
 //constructor
 FGRidgeLift::FGRidgeLift ()
 {	
@@ -49,19 +62,8 @@ FGRidgeLift::FGRidgeLift ()
 	dist_probe_m[3] = 2000.0;
 	dist_probe_m[4] = -100.0;
 
-	BOUNDARY1_m = 40.0; // in meters
-	BOUNDARY2_m = 130.0; 
-
-	PI = 4.0*atan(1.0); // pi
-	deg2rad = (PI/180.0);
-	rad2deg = (180.0/PI);
 	strength = 0.0;
 	timer = 0.0;
-	scanned = false;
-
-	earth_rad_ft=20899773.07;
-        for( int i = 0; i < sizeof(probe_elev_m)/sizeof(probe_elev_m[0]); i++ )
-          probe_elev_m[i] = 0.0;
 }
 
 //destructor
@@ -72,259 +74,165 @@ FGRidgeLift::~FGRidgeLift()
 
 void FGRidgeLift::init(void)
 {
-	_ridge_lift_fps_node =
-			fgGetNode("/environment/ridge-lift-fps"
-			, true);
+	_ridge_lift_fps_node = fgGetNode("/environment/ridge-lift-fps", true);
 	_surface_wind_from_deg_node =
 			fgGetNode("/environment/config/boundary/entry[0]/wind-from-heading-deg"
 			, true);
 	_surface_wind_speed_node =
 			fgGetNode("/environment/config/boundary/entry[0]/wind-speed-kt"
 			, true);
-	_earth_radius_node =
-			fgGetNode("/position/sea-level-radius-ft"
-			, true);
-	_user_longitude_node =
-			fgGetNode("/position/longitude-deg"
-			, true);
-	_user_latitude_node =
-			fgGetNode("/position/latitude-deg"
-			, true);
-	_user_altitude_ft_node =
-			fgGetNode("/position/altitude-ft"
-			, true);
-	_user_altitude_agl_ft_node =
-			fgGetNode("/position/altitude-agl-ft"
-			, true);
+	_earth_radius_node = fgGetNode("/position/sea-level-radius-ft", true);
+	_user_longitude_node = fgGetNode("/position/longitude-deg", true);
+	_user_latitude_node = fgGetNode("/position/latitude-deg", true);
+	_user_altitude_ft_node = fgGetNode("/position/altitude-ft", true);
+	_user_altitude_agl_ft_node = fgGetNode("/position/altitude-agl-ft", true);
 }
 
 void FGRidgeLift::bind() {
+	string prop;
 
-	fgTie("/environment/ridge-lift/probe-elev-m[0]", this,
-		&FGRidgeLift::get_probe_elev_m_0); // read-only
-	fgTie("/environment/ridge-lift/probe-elev-m[1]", this,
-		&FGRidgeLift::get_probe_elev_m_1); // read-only
-	fgTie("/environment/ridge-lift/probe-elev-m[2]", this,
-		&FGRidgeLift::get_probe_elev_m_2); // read-only
-	fgTie("/environment/ridge-lift/probe-elev-m[3]", this,
-		&FGRidgeLift::get_probe_elev_m_3); // read-only
-	fgTie("/environment/ridge-lift/probe-elev-m[4]", this,
-		&FGRidgeLift::get_probe_elev_m_4); // read-only
+	for( int i = 0; i < 5; i++ ) {
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/probe-elev-m", i );
+		fgTie( prop.c_str(), this, i, &FGRidgeLift::get_probe_elev_m); // read-only
 
-	fgTie("/environment/ridge-lift/probe-lat-deg[0]", this,
-		&FGRidgeLift::get_probe_lat_0); // read-only
-	fgTie("/environment/ridge-lift/probe-lat-deg[1]", this,
-		&FGRidgeLift::get_probe_lat_1); // read-only
-	fgTie("/environment/ridge-lift/probe-lat-deg[2]", this,
-		&FGRidgeLift::get_probe_lat_2); // read-only
-	fgTie("/environment/ridge-lift/probe-lat-deg[3]", this,
-		&FGRidgeLift::get_probe_lat_3); // read-only
-	fgTie("/environment/ridge-lift/probe-lat-deg[4]", this,
-		&FGRidgeLift::get_probe_lat_4); // read-only
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/probe-lat-deg", i );
+		fgTie( prop.c_str(), this, i, &FGRidgeLift::get_probe_lat_deg); // read-only
 
-	fgTie("/environment/ridge-lift/probe-lon-deg[0]", this,
-		&FGRidgeLift::get_probe_lon_0); // read-only
-	fgTie("/environment/ridge-lift/probe-lon-deg[1]", this,
-		&FGRidgeLift::get_probe_lon_1); // read-only
-	fgTie("/environment/ridge-lift/probe-lon-deg[2]", this,
-		&FGRidgeLift::get_probe_lon_2); // read-only
-	fgTie("/environment/ridge-lift/probe-lon-deg[3]", this,
-		&FGRidgeLift::get_probe_lon_3); // read-only
-	fgTie("/environment/ridge-lift/probe-lon-deg[4]", this,
-		&FGRidgeLift::get_probe_lon_4); // read-only
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/probe-lon-deg", i );
+		fgTie( prop.c_str(), this, i, &FGRidgeLift::get_probe_lon_deg); // read-only
+	}
 
-	fgTie("/environment/ridge-lift/slope[0]", this,
-		&FGRidgeLift::get_slope_0); // read-only
-	fgTie("/environment/ridge-lift/slope[1]", this,
-		&FGRidgeLift::get_slope_1); // read-only
-	fgTie("/environment/ridge-lift/slope[2]", this,
-		&FGRidgeLift::get_slope_2); // read-only
-	fgTie("/environment/ridge-lift/slope[3]", this,
-		&FGRidgeLift::get_slope_3); // read-only
-	
+	for( int i = 0; i < 4; i++ ) {
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/slope", i );
+		fgTie( prop.c_str(), this, i, &FGRidgeLift::get_slope); // read-only
+	}
 }
 
 void FGRidgeLift::unbind() {
+	string prop;
 
-	fgUntie("/environment/ridge-lift/probe-elev-m[0]");
-	fgUntie("/environment/ridge-lift/probe-elev-m[1]");
-	fgUntie("/environment/ridge-lift/probe-elev-m[2]");
-	fgUntie("/environment/ridge-lift/probe-elev-m[3]");
-	fgUntie("/environment/ridge-lift/probe-elev-m[4]");
+	for( int i = 0; i < 5; i++ ) {
 
-	fgUntie("/environment/ridge-lift/probe-lat-deg[0]");
-	fgUntie("/environment/ridge-lift/probe-lat-deg[1]");
-	fgUntie("/environment/ridge-lift/probe-lat-deg[2]");
-	fgUntie("/environment/ridge-lift/probe-lat-deg[3]");
-	fgUntie("/environment/ridge-lift/probe-lat-deg[4]");
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/probe-elev-m", i );
+		fgUntie( prop.c_str() );
 
-	fgUntie("/environment/ridge-lift/probe-lon-deg[0]");
-	fgUntie("/environment/ridge-lift/probe-lon-deg[1]");
-	fgUntie("/environment/ridge-lift/probe-lon-deg[2]");
-	fgUntie("/environment/ridge-lift/probe-lon-deg[3]");
-	fgUntie("/environment/ridge-lift/probe-lon-deg[4]");
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/probe-lat-deg", i );
+		fgUntie( prop.c_str() );
 
-	fgUntie("/environment/ridge-lift/slope[0]");
-	fgUntie("/environment/ridge-lift/slope[1]");
-	fgUntie("/environment/ridge-lift/slope[2]");
-	fgUntie("/environment/ridge-lift/slope[3]");
-	
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/probe-lon-deg", i );
+		fgUntie( prop.c_str() );
+	}
+
+	for( int i = 0; i < 4; i++ ) {
+		prop = CreateIndexedPropertyName("/environment/ridge-lift/slope", i );
+		fgUntie( prop.c_str() );
+	}
 }
 
 void FGRidgeLift::update(double dt) {
-	Run(dt);
-}
 
-double FGRidgeLift::sign(double x) {
-    if (x == 0.0)
-        return x;
-    else
-        return x/fabs(x);
-}
-
-void FGRidgeLift::Run(double dt) {
-
-	// copy values 
-
-	user_latitude_deg  = _user_latitude_node->getDoubleValue();
-	user_longitude_deg = _user_longitude_node->getDoubleValue();
-	//user_altitude_ft  = _user_altitude_ft_node->getDoubleValue();
-	
-	if ( ( _earth_radius_node->getDoubleValue() ) > 1.0 ) {
-	earth_rad_ft =_earth_radius_node->getDoubleValue(); }
-	else {	earth_rad_ft=20899773.07; }
-
-	//earth_rad_m = earth_rad_ft * 0.3048 ;
-	earth_rad_m = earth_rad_ft * SG_FEET_TO_METER ;
-	
 	//get the windspeed at ground level
 
-	double ground_wind_from_deg = _surface_wind_from_deg_node->getDoubleValue();
-	double ground_wind_speed_kts  = _surface_wind_speed_node->getDoubleValue();
-	//double ground_wind_speed_mps = ground_wind_speed_kts / SG_METER_TO_FEET;
-	double ground_wind_speed_mps = ground_wind_speed_kts / 3.2808399;
+	double ground_wind_from_rad = _surface_wind_from_deg_node->getDoubleValue() * SG_DEGREES_TO_RADIANS;
+	double ground_wind_speed_mps = _surface_wind_speed_node->getDoubleValue() * SG_NM_TO_METER / 3600;
 
-	//double ground_wind_from_rad = (user_longitude_deg < 0.0)  ? 
-	//	PI*( ground_wind_from_deg/180.0) +PI : PI*( ground_wind_from_deg/180.0);
-	double ground_wind_from_rad = PI*( ground_wind_from_deg/180.0);
-
-	// Placing the probes
-	
-	for (int i = 0; i <= 4; i++)
-	{
-			probe_lat_rad[i] = asin(sin(deg2rad*user_latitude_deg)*cos(dist_probe_m[i]/earth_rad_m)
-				+cos(deg2rad*user_latitude_deg)*sin(dist_probe_m[i]/earth_rad_m)*cos(ground_wind_from_rad));
-		if (probe_lat_rad[i] == 0.0) {
-			probe_lon_rad[i] = (deg2rad*user_latitude_deg);      // probe on a pole	
-		}
-		else {
-			probe_lon_rad[i] = fmod((deg2rad*user_longitude_deg+asin(sin(ground_wind_from_rad)
-						*sin(dist_probe_m[i]/earth_rad_m)/cos(probe_lat_rad[i]))+PI)
-					,(2.0*PI))-PI;
-		}
-		probe_lat_deg[i]= rad2deg*probe_lat_rad[i];
-		probe_lon_deg[i]= rad2deg*probe_lon_rad[i];
-	}
-	
-	// ground elevations
-	// every second
-	
 	timer -= dt;
 	if (timer <= 0.0 ) {
-		for (int i = 0; i <= 4; i++)
-		{
-			if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(
-			    SGGeod::fromRad(probe_lon_rad[i],probe_lat_rad[i]), 20000), alt, 0))
-			{
-				if ( alt > 0.1 ) { probe_elev_m[i] =  alt; } else { probe_elev_m[i] = 0.1 ;};
-			}
-			else { probe_elev_m[i] = 0.1;};
-		}
-		timer = 1.0;
-		
-	}
+		// copy values 
 
-	// slopes
+		double user_latitude_rad = _user_latitude_node->getDoubleValue() * SG_DEGREES_TO_RADIANS;
+		double user_longitude_rad = _user_longitude_node->getDoubleValue() * SG_DEGREES_TO_RADIANS;
 	
-	double adj_slope[4];
+		double earth_rad_m = _earth_radius_node->getDoubleValue() * SG_FEET_TO_METER;
+		if( earth_rad_m < SG_EPSILON )
+				earth_rad_m = SG_EARTH_RAD * 1000;
+
+		// Placing the probes
 	
-	slope[0] = (probe_elev_m[0] - probe_elev_m[1]) / dist_probe_m[1];
-	slope[1] = (probe_elev_m[1] - probe_elev_m[2]) / dist_probe_m[2];
-	slope[2] = (probe_elev_m[2] - probe_elev_m[3]) / dist_probe_m[3];
-	slope[3] = (probe_elev_m[4] - probe_elev_m[0]) / -dist_probe_m[4];
+		for (int i = 0; i < sizeof(probe_lat_rad)/sizeof(probe_lat_rad[0]); i++) {
+			double probe_radius_ratio = dist_probe_m[i]/earth_rad_m;
+
+			probe_lat_rad[i] = asin(sin(user_latitude_rad)*cos(probe_radius_ratio)
+					+cos(user_latitude_rad)*sin(probe_radius_ratio)*cos(ground_wind_from_rad));
+			if (probe_lat_rad[i] < SG_EPSILON ) {
+				probe_lon_rad[i] = user_latitude_rad; // probe on a pole	
+			} else {
+				probe_lon_rad[i] = fmod((user_longitude_rad+asin(sin(ground_wind_from_rad)
+							*sin(probe_radius_ratio)/cos(probe_lat_rad[i]))+SG_PI)
+						,SGD_2PI)-SG_PI;
+			}
+			probe_lat_deg[i]= probe_lat_rad[i] * SG_RADIANS_TO_DEGREES;
+			probe_lon_deg[i]= probe_lon_rad[i] * SG_RADIANS_TO_DEGREES;
+		}
 	
-	for (int i = 0; i < 4; i++)
-	{	
-		adj_slope[i] = sin(atan(5.0 * pow ( (fabs(slope[i])),1.7) ) ) *sign(slope[i]);
+		for (int i = 0; i < sizeof(probe_elev_m)/sizeof(probe_elev_m[0]); i++) {
+			if (globals->get_scenery()->get_elevation_m(SGGeod::fromGeodM(
+				SGGeod::fromRad(probe_lon_rad[i],probe_lat_rad[i]), 20000), alt, 0)) {
+				if ( alt > 0.1 ) { 
+					probe_elev_m[i] = alt; 
+				} else { 
+					probe_elev_m[i] = 0.1 ;
+				}
+			} else { 
+				probe_elev_m[i] = 0.1;
+			}
+		}
+
+		// slopes
+		double adj_slope[4];
+		slope[0] = (probe_elev_m[0] - probe_elev_m[1]) / dist_probe_m[1];
+		slope[1] = (probe_elev_m[1] - probe_elev_m[2]) / dist_probe_m[2];
+		slope[2] = (probe_elev_m[2] - probe_elev_m[3]) / dist_probe_m[3];
+		slope[3] = (probe_elev_m[4] - probe_elev_m[0]) / -dist_probe_m[4];
+	
+		for (int i = 0; i < sizeof(slope)/sizeof(slope[0]); i++)
+			adj_slope[i] = sin(atan(5.0 * pow ( (fabs(slope[i])),1.7) ) ) *sign(slope[i]);
+	
+		//adjustment
+		adj_slope[0] = 0.2 * adj_slope[0];
+		adj_slope[1] = 0.2 * adj_slope[1];
+		if ( adj_slope [2] < 0.0 ) {
+			adj_slope[2] = 0.5 * adj_slope[2];
+		} else {
+			adj_slope[2] = 0.0 ;
+		}
+	
+		if ( ( adj_slope [0] >= 0.0 ) && ( adj_slope [3] < 0.0 ) ) {
+			adj_slope[3] = 0.0;
+		} else {
+			adj_slope[3] = 0.2 * adj_slope[3];
+		}
+		lift_factor = adj_slope[0]+adj_slope[1]+adj_slope[2]+adj_slope[3];
+	
+		// restart the timer
+		timer = 1.0;
 	}
 	
-	//adjustment
-	
-	adj_slope[0] = 0.2 * adj_slope[0];
-	adj_slope[1] = 0.2 * adj_slope[1];
-	if ( adj_slope [2] < 0.0 )
-	{
-		adj_slope[2] = 0.5 * adj_slope[2];
-	}
-	else 
-	{
-		adj_slope[2] = 0.0 ;
-	}
-	
-	if ( ( adj_slope [0] >= 0.0 ) && ( adj_slope [3] < 0.0 ) )
-	{
-		adj_slope[3] = 0.0;
-	}
-	else 
-	{
-		adj_slope[3] = 0.2 * adj_slope[3];
-	}
-	
-	double lift_factor = adj_slope[0]+adj_slope[1]+adj_slope[2]+adj_slope[3];
-	
 	//user altitude above ground
-	
-	user_altitude_agl_ft = _user_altitude_agl_ft_node->getDoubleValue();
-	user_altitude_agl_m = ( user_altitude_agl_ft / SG_METER_TO_FEET );
+	double user_altitude_agl_m = _user_altitude_agl_ft_node->getDoubleValue() * SG_FEET_TO_METER;
 	
 	//boundaries
-	double agl_factor;
-
-	if (lift_factor < 0.0) // in the sink
-	{
+  double boundary2_m = 130.0; // in the lift
+	if (lift_factor < 0.0) { // in the sink
 		double highest_probe_temp= max ( probe_elev_m[1], probe_elev_m[2] );
 		double highest_probe_downwind_m= max ( highest_probe_temp, probe_elev_m[3] );
-		BOUNDARY2_m = highest_probe_downwind_m - probe_elev_m[0];
-	}
-	else // in the lift
-	{
-		BOUNDARY2_m = 130.0;
+		boundary2_m = highest_probe_downwind_m - probe_elev_m[0];
 	}
 
-	if ( user_altitude_agl_m < BOUNDARY1_m )
-	{
+	double agl_factor;
+	if ( user_altitude_agl_m < BOUNDARY1_m ) {
 		agl_factor = 0.5+0.5*user_altitude_agl_m /BOUNDARY1_m ;
-	}
-	else if ( user_altitude_agl_m < BOUNDARY2_m )
-	{
+	} else if ( user_altitude_agl_m < boundary2_m ) {
 		agl_factor = 1.0;
-	}
-	else
-	{
-		agl_factor =  exp(-(2 + 2 * probe_elev_m[0] / 4000) * 
-				(user_altitude_agl_m - BOUNDARY2_m) / max(probe_elev_m[0],200.0));
+	} else {
+		agl_factor = exp(-(2 + probe_elev_m[0] / 2000) * 
+				(user_altitude_agl_m - boundary2_m) / max(probe_elev_m[0],200.0));
 	}
 	
 	double lift_mps = lift_factor* ground_wind_speed_mps * agl_factor;
 	
 	//the updraft, finally, in ft per second
-	strength = lift_mps * SG_METER_TO_FEET ;
+	strength = fgGetLowPass( strength, lift_mps * SG_METER_TO_FEET, dt );
 //  	if(isnan(strength)) strength=0; 
  	 _ridge_lift_fps_node->setDoubleValue( strength );
 }
-
-
-
-
-
-
diff --git a/src/Environment/ridge_lift.hxx b/src/Environment/ridge_lift.hxx
index c6f49ecf2..a4768d8de 100644
--- a/src/Environment/ridge_lift.hxx
+++ b/src/Environment/ridge_lift.hxx
@@ -50,41 +50,15 @@ public:
 
 	inline double getStrength() const { return strength; };
 
- 	inline double get_probe_elev_m_0() const { return probe_elev_m[0]; };
- 	inline double get_probe_elev_m_1() const { return probe_elev_m[1]; };
- 	inline double get_probe_elev_m_2() const { return probe_elev_m[2]; };
- 	inline double get_probe_elev_m_3() const { return probe_elev_m[3]; };
- 	inline double get_probe_elev_m_4() const { return probe_elev_m[4]; };
-
- 	inline double get_probe_lat_0() const { return probe_lat_deg[0]; };
- 	inline double get_probe_lat_1() const { return probe_lat_deg[1]; };
- 	inline double get_probe_lat_2() const { return probe_lat_deg[2]; };
- 	inline double get_probe_lat_3() const { return probe_lat_deg[3]; };
- 	inline double get_probe_lat_4() const { return probe_lat_deg[4]; };
-
-	inline double get_probe_lon_0() const { return probe_lon_deg[0]; };
- 	inline double get_probe_lon_1() const { return probe_lon_deg[1]; };
- 	inline double get_probe_lon_2() const { return probe_lon_deg[2]; };
- 	inline double get_probe_lon_3() const { return probe_lon_deg[3]; };
- 	inline double get_probe_lon_4() const { return probe_lon_deg[4]; };
-
- 	inline double get_slope_0() const { return slope[0]; };
- 	inline double get_slope_1() const { return slope[1]; };
- 	inline double get_slope_2() const { return slope[2]; };
- 	inline double get_slope_3() const { return slope[3]; };
+ 	inline double get_probe_elev_m( int index ) const { return probe_elev_m[index]; };
+ 	inline double get_probe_lat_deg( int index ) const { return probe_lat_deg[index]; };
+	inline double get_probe_lon_deg( int index ) const { return probe_lon_deg[index]; };
+ 	inline double get_slope( int index ) const { return slope[index]; };
 
 private:
 	//void init();
-	void Run(double dt);
 
 	double dist_probe_m[5];
-	double BOUNDARY1_m;
-	double BOUNDARY2_m;
-	double PI; // pi
-	double deg2rad;
-	double rad2deg;
-
-	bool scanned;
 
 	double strength;
 	double timer;
@@ -99,15 +73,13 @@ private:
 	double probe_elev_m[5];
 
 	double slope[4];
-	double earth_rad_ft;
-	double earth_rad_m;
-	double user_latitude_deg;
-	double user_longitude_deg;
-	//double user_altitude;
-	double user_altitude_agl_ft;
-	double user_altitude_agl_m;
 
-	double sign(double x);
+	double lift_factor;
+
+	inline double sign(double x) const {
+		if( x == 0 ) return 0;
+		return x > 0 ? 1.0 : -1.0;
+	}
 
 	SGPropertyNode_ptr _ridge_lift_fps_node;
 
@@ -122,4 +94,4 @@ private:
 
 };
 
-#endif  // _FG_RidgeLift_HXX
\ No newline at end of file
+#endif  // _FG_RidgeLift_HXX