diff --git a/libraries/AC_AutoTune/AC_AutoTune_Heli.cpp b/libraries/AC_AutoTune/AC_AutoTune_Heli.cpp
index b227d3b2f402f..7e8c49297ec70 100644
--- a/libraries/AC_AutoTune/AC_AutoTune_Heli.cpp
+++ b/libraries/AC_AutoTune/AC_AutoTune_Heli.cpp
@@ -822,8 +822,8 @@ void AC_AutoTune_Heli::dwell_test_run(sweep_info &test_data)
         filt_att_fdbk_from_velxy_cd.apply(att_fdbk, AP::scheduler().get_loop_period_s());
     } else {
         target_angle_cd = 0.0f;
-        trim_yaw_tgt_reading = (float)attitude_control->get_att_target_euler_cd().z;
-        trim_yaw_heading_reading = (float)ahrs_view->yaw_sensor;
+        trim_yaw_tgt_reading_cd = (float)attitude_control->get_att_target_euler_cd().z;
+        trim_yaw_heading_reading_cd = (float)ahrs_view->yaw_sensor;
         dwell_start_time_ms = now;
         filt_att_fdbk_from_velxy_cd.reset(Vector2f(0.0f,0.0f));
         settle_time--;
@@ -865,17 +865,17 @@ void AC_AutoTune_Heli::dwell_test_run(sweep_info &test_data)
         break;
     case YAW:
     case YAW_D:
-        attitude_control->input_euler_angle_roll_pitch_yaw(trim_angle_cd.x, trim_angle_cd.y, wrap_180_cd(trim_yaw_tgt_reading + target_angle_cd), false);
+        attitude_control->input_euler_angle_roll_pitch_yaw(trim_angle_cd.x, trim_angle_cd.y, wrap_180_cd(trim_yaw_tgt_reading_cd + target_angle_cd), false);
         command_reading = motors->get_yaw();
         if (test_calc_type == DRB) {
             tgt_rate_reading = radians(target_angle_cd * 0.01f);
-            gyro_reading = radians((wrap_180_cd((float)ahrs_view->yaw_sensor - trim_yaw_heading_reading - target_angle_cd)) * 0.01f);
+            gyro_reading = radians((wrap_180_cd((float)ahrs_view->yaw_sensor - trim_yaw_heading_reading_cd - target_angle_cd)) * 0.01f);
         } else if (test_calc_type == RATE) {
             tgt_rate_reading = attitude_control->rate_bf_targets().z;
             gyro_reading = ahrs_view->get_gyro().z;
         } else {
-            tgt_rate_reading = radians((wrap_180_cd((float)attitude_control->get_att_target_euler_cd().z - trim_yaw_tgt_reading)) * 0.01f);
-            gyro_reading = radians((wrap_180_cd((float)ahrs_view->yaw_sensor - trim_yaw_heading_reading)) * 0.01f);
+            tgt_rate_reading = radians((wrap_180_cd((float)attitude_control->get_att_target_euler_cd().z - trim_yaw_tgt_reading_cd)) * 0.01f);
+            gyro_reading = radians((wrap_180_cd((float)ahrs_view->yaw_sensor - trim_yaw_heading_reading_cd)) * 0.01f);
         }
         break;
     }
diff --git a/libraries/AC_AutoTune/AC_AutoTune_Heli.h b/libraries/AC_AutoTune/AC_AutoTune_Heli.h
index 269d3047c172e..a9dfee98d698b 100644
--- a/libraries/AC_AutoTune/AC_AutoTune_Heli.h
+++ b/libraries/AC_AutoTune/AC_AutoTune_Heli.h
@@ -263,10 +263,6 @@ class AC_AutoTune_Heli : public AC_AutoTune
     uint32_t settle_time;                           // time in ms for allowing aircraft to stabilize before initiating test
     float    trim_meas_rate;                        // trim measured gyro rate
 
-    //variables from rate FF test
-    float trim_command_reading;
-    float trim_heading;
-
     // variables from dwell test
     LowPassFilterVector2f filt_att_fdbk_from_velxy_cd;
     LowPassFilterFloat filt_command_reading;        // filtered command reading to keep oscillation centered
@@ -274,10 +270,8 @@ class AC_AutoTune_Heli : public AC_AutoTune
     LowPassFilterFloat filt_tgt_rate_reading;       // filtered target rate reading to keep oscillation centered
 
     // trim variables for determining trim state prior to test starting
-    Vector3f trim_attitude_cd;                      // trim attitude before starting test
-    float trim_command;                             // trim target yaw reading before starting test
-    float trim_yaw_tgt_reading;                     // trim target yaw reading before starting test
-    float trim_yaw_heading_reading;                 // trim heading reading before starting test
+    float trim_yaw_tgt_reading_cd;                     // trim target yaw reading before starting test
+    float trim_yaw_heading_reading_cd;                 // trim heading reading before starting test
 
     LowPassFilterFloat  command_filt;               // filtered command - filtering intended to remove noise
     LowPassFilterFloat  target_rate_filt;           // filtered target rate in radians/second - filtering intended to remove noise