diff --git a/libraries/AP_NavEKF2/AP_NavEKF2.cpp b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
index b5d5431b89..ab6e8f6d01 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2.cpp
@@ -1189,21 +1189,26 @@ void NavEKF2::getQuaternion(int8_t instance, Quaternion &quat) const
 }
 
 // return the innovations for the specified instance
-void NavEKF2::getInnovations(int8_t instance, Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const
+bool NavEKF2::getInnovations(int8_t instance, Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const
 {
-    if (instance < 0 || instance >= num_cores) instance = primary;
-    if (core) {
-        core[instance].getInnovations(velInnov, posInnov, magInnov, tasInnov, yawInnov);
+    if (core == nullptr) {
+        return false;
     }
+
+    if (instance < 0 || instance >= num_cores) instance = primary;
+
+    return core[instance].getInnovations(velInnov, posInnov, magInnov, tasInnov, yawInnov);
 }
 
 // return the innovation consistency test ratios for the velocity, position, magnetometer and true airspeed measurements
-void NavEKF2::getVariances(int8_t instance, float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const
+bool NavEKF2::getVariances(int8_t instance, float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const
 {
-    if (instance < 0 || instance >= num_cores) instance = primary;
-    if (core) {
-        core[instance].getVariances(velVar, posVar, hgtVar, magVar, tasVar, offset);
+    if (core == nullptr) {
+        return false;
     }
+    if (instance < 0 || instance >= num_cores) instance = primary;
+
+    return core[instance].getVariances(velVar, posVar, hgtVar, magVar, tasVar, offset);
 }
 
 // should we use the compass? This is public so it can be used for
diff --git a/libraries/AP_NavEKF2/AP_NavEKF2.h b/libraries/AP_NavEKF2/AP_NavEKF2.h
index 6fec6576cb..27c03ebd2c 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2.h
+++ b/libraries/AP_NavEKF2/AP_NavEKF2.h
@@ -173,11 +173,11 @@ public:
 
     // return the innovations for the specified instance
     // An out of range instance (eg -1) returns data for the primary instance
-    void  getInnovations(int8_t index, Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const;
+    bool getInnovations(int8_t index, Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const;
 
     // return the innovation consistency test ratios for the specified instance
     // An out of range instance (eg -1) returns data for the primary instance
-    void  getVariances(int8_t instance, float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const;
+    bool getVariances(int8_t instance, float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const;
 
     // should we use the compass? This is public so it can be used for
     // reporting via ahrs.use_compass()
diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_Outputs.cpp b/libraries/AP_NavEKF2/AP_NavEKF2_Outputs.cpp
index d7716e85e3..21bcd3eb8b 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_Outputs.cpp
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_Outputs.cpp
@@ -399,7 +399,7 @@ bool NavEKF2_core::getMagOffsets(uint8_t mag_idx, Vector3f &magOffsets) const
 }
 
 // return the innovations for the NED Pos, NED Vel, XYZ Mag and Vtas measurements
-void  NavEKF2_core::getInnovations(Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const
+bool NavEKF2_core::getInnovations(Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const
 {
     velInnov.x = innovVelPos[0];
     velInnov.y = innovVelPos[1];
@@ -412,12 +412,14 @@ void  NavEKF2_core::getInnovations(Vector3f &velInnov, Vector3f &posInnov, Vecto
     magInnov.z = 1e3f*innovMag[2]; // Convert back to sensor units
     tasInnov   = innovVtas;
     yawInnov   = innovYaw;
+
+    return true;
 }
 
 // return the innovation consistency test ratios for the velocity, position, magnetometer and true airspeed measurements
 // this indicates the amount of margin available when tuning the various error traps
 // also return the delta in position due to the last position reset
-void  NavEKF2_core::getVariances(float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const
+bool NavEKF2_core::getVariances(float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const
 {
     velVar   = sqrtF(velTestRatio);
     posVar   = sqrtF(posTestRatio);
@@ -428,6 +430,8 @@ void  NavEKF2_core::getVariances(float &velVar, float &posVar, float &hgtVar, Ve
     magVar.z = sqrtF(MAX(magTestRatio.z,yawTestRatio));
     tasVar   = sqrtF(tasTestRatio);
     offset   = posResetNE.tofloat();
+
+    return true;
 }
 
 
@@ -532,7 +536,7 @@ void NavEKF2_core::send_status_report(mavlink_channel_t chan) const
     }
 
     // get variances
-    float velVar, posVar, hgtVar, tasVar;
+    float velVar = 0, posVar = 0, hgtVar = 0, tasVar = 0;
     Vector3f magVar;
     Vector2f offset;
     getVariances(velVar, posVar, hgtVar, magVar, tasVar, offset);
diff --git a/libraries/AP_NavEKF2/AP_NavEKF2_core.h b/libraries/AP_NavEKF2/AP_NavEKF2_core.h
index 3ff0952b34..1b36283990 100644
--- a/libraries/AP_NavEKF2/AP_NavEKF2_core.h
+++ b/libraries/AP_NavEKF2/AP_NavEKF2_core.h
@@ -184,10 +184,10 @@ public:
     void getQuaternion(Quaternion &quat) const;
 
     // return the innovations for the NED Pos, NED Vel, XYZ Mag and Vtas measurements
-    void  getInnovations(Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const;
+    bool getInnovations(Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const;
 
     // return the innovation consistency test ratios for the velocity, position, magnetometer and true airspeed measurements
-    void  getVariances(float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const;
+    bool getVariances(float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const;
 
     // should we use the compass? This is public so it can be used for
     // reporting via ahrs.use_compass()