diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
index aa2a169813..cc464f1046 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp
@@ -707,7 +707,7 @@ void NavEKF3_core::readBaroData()
 
         // If we are in takeoff mode, the height measurement is limited to be no less than the measurement at start of takeoff
         // This prevents negative baro disturbances due to copter downwash corrupting the EKF altitude during initial ascent
-        if (getTakeoffExpected()) {
+        if (getTakeoffExpected() && !assume_zero_sideslip()) {
             baroDataNew.hgt = MAX(baroDataNew.hgt, meaHgtAtTakeOff);
         }
 
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_PosVelFusion.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_PosVelFusion.cpp
index c8ab996abe..585b776980 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_PosVelFusion.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_PosVelFusion.cpp
@@ -1071,7 +1071,7 @@ void NavEKF3_core::selectHeightForFusion()
         }
         // filtered baro data used to provide a reference for takeoff
         // it is is reset to last height measurement on disarming in performArmingChecks()
-        if (!getTakeoffExpected()) {
+        if (!getTakeoffExpected() || !assume_zero_sideslip()) {
             const float gndHgtFiltTC = 0.5f;
             const float dtBaro = frontend->hgtAvg_ms*1.0e-3f;
             float alpha = constrain_float(dtBaro / (dtBaro+gndHgtFiltTC),0.0f,1.0f);
@@ -1132,12 +1132,12 @@ void NavEKF3_core::selectHeightForFusion()
         // set the observation noise
         posDownObsNoise = sq(constrain_float(frontend->_baroAltNoise, 0.1f, 10.0f));
         // reduce weighting (increase observation noise) on baro if we are likely to be in ground effect
-        if (getTakeoffExpected() || getTouchdownExpected()) {
+        if ((getTakeoffExpected() && !assume_zero_sideslip()) || getTouchdownExpected()) {
             posDownObsNoise *= frontend->gndEffectBaroScaler;
         }
         // If we are in takeoff mode, the height measurement is limited to be no less than the measurement at start of takeoff
         // This prevents negative baro disturbances due to copter downwash corrupting the EKF altitude during initial ascent
-        if (motorsArmed && getTakeoffExpected()) {
+        if (motorsArmed && (getTakeoffExpected() && !assume_zero_sideslip())) {
             hgtMea = MAX(hgtMea, meaHgtAtTakeOff);
         }
         velPosObs[5] = -hgtMea;
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp
index ac82c39a11..e245c9127f 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp
@@ -412,7 +412,7 @@ void NavEKF3_core::detectFlight()
     if (!prevOnGround && onGround) {
         // landed so disable filter bank
         EKFGSF_run_filterbank = false;
-    } else if (!prevInFlight && inFlight) {
+    } else if (!EKFGSF_run_filterbank && ((!prevInFlight && inFlight) || getTakeoffExpected())) {
         // started flying so reset counters and enable filter bank
         EKFGSF_yaw_reset_ms = 0;
         EKFGSF_yaw_reset_request_ms = 0;
@@ -429,8 +429,8 @@ void NavEKF3_core::detectFlight()
 
 }
 
-
-// determine if a takeoff is expected so that we can compensate for expected barometer errors due to ground effect
+// determine if a takeoff is expected so that we can compensate for expected barometer errors due to rotor wash ground interaction
+// also used when in fixed wing mode so that GSG yaw estimator can be started before throw or takeoff roll
 bool NavEKF3_core::getTakeoffExpected()
 {
     if (expectGndEffectTakeoff && imuSampleTime_ms - takeoffExpectedSet_ms > frontend->gndEffectTimeout_ms) {