diff --git a/EKF/common.h b/EKF/common.h
index f2b4676667..643ccecdb5 100644
--- a/EKF/common.h
+++ b/EKF/common.h
@@ -266,6 +266,7 @@ struct parameters {
 	float max_vel_for_range_aid{1.0f};	///< maximum ground velocity for which we allow to use the range finder as height source (if range_aid == 1)
 	int32_t range_aid{0};			///< allow switching primary height source to range finder if certian conditions are met
 	float range_aid_innov_gate{1.0f}; 	///< gate size used for innovation consistency checks for range aid fusion
+	float range_cos_max_tilt{0.7071f};	///< cosine of the maximum tilt angle from the vertical that permits use of range finder data
 
 	// vision position fusion
 	float ev_innov_gate{5.0f};		///< vision estimator fusion innovation consistency gate size (STD)
diff --git a/EKF/control.cpp b/EKF/control.cpp
index 02a28884eb..ac5ca71020 100644
--- a/EKF/control.cpp
+++ b/EKF/control.cpp
@@ -103,7 +103,7 @@ void Ekf::controlFusionModes()
 	// calculate 2,2 element of rotation matrix from sensor frame to earth frame
 	_R_rng_to_earth_2_2 = _R_to_earth(2, 0) * _sin_tilt_rng + _R_to_earth(2, 2) * _cos_tilt_rng;
 	_range_data_ready = _range_buffer.pop_first_older_than(_imu_sample_delayed.time_us, &_range_sample_delayed)
-			&& (_R_rng_to_earth_2_2 > 0.7071f);
+			&& (_R_rng_to_earth_2_2 > _params.range_cos_max_tilt);
 
 	checkForStuckRange();
 
diff --git a/EKF/terrain_estimator.cpp b/EKF/terrain_estimator.cpp
index 5d4b5c1fd7..d6dfff8814 100644
--- a/EKF/terrain_estimator.cpp
+++ b/EKF/terrain_estimator.cpp
@@ -47,7 +47,7 @@ bool Ekf::initHagl()
 	// get most recent range measurement from buffer
 	rangeSample latest_measurement = _range_buffer.get_newest();
 
-	if ((_time_last_imu - latest_measurement.time_us) < 2e5 && _R_rng_to_earth_2_2 > 0.7071f) {
+	if ((_time_last_imu - latest_measurement.time_us) < 2e5 && _R_rng_to_earth_2_2 > _params.range_cos_max_tilt) {
 		// if we have a fresh measurement, use it to initialise the terrain estimator
 		_terrain_vpos = _state.pos(2) + latest_measurement.rng * _R_rng_to_earth_2_2;
 		// initialise state variance to variance of measurement
@@ -113,7 +113,7 @@ void Ekf::runTerrainEstimator()
 void Ekf::fuseHagl()
 {
 	// If the vehicle is excessively tilted, do not try to fuse range finder observations
-	if (_R_rng_to_earth_2_2 > 0.7071f) {
+	if (_R_rng_to_earth_2_2 > _params.range_cos_max_tilt) {
 		// get a height above ground measurement from the range finder assuming a flat earth
 		float meas_hagl = _range_sample_delayed.rng * _R_rng_to_earth_2_2;
 
diff --git a/EKF/vel_pos_fusion.cpp b/EKF/vel_pos_fusion.cpp
index b4ee09e446..01284defa5 100644
--- a/EKF/vel_pos_fusion.cpp
+++ b/EKF/vel_pos_fusion.cpp
@@ -179,7 +179,7 @@ void Ekf::fuseVelPosHeight()
 			// innovation gate size
 			gate_size[5] = fmaxf(_params.baro_innov_gate, 1.0f);
 
-		} else if (_control_status.flags.rng_hgt && (_R_rng_to_earth_2_2 > 0.7071f)) {
+		} else if (_control_status.flags.rng_hgt && (_R_rng_to_earth_2_2 > _params.range_cos_max_tilt)) {
 			fuse_map[5] = true;
 			// use range finder with tilt correction
 			_vel_pos_innov[5] = _state.pos(2) - (-math::max(_range_sample_delayed.rng * _R_rng_to_earth_2_2,