diff --git a/APMrover2/GCS_Mavlink.cpp b/APMrover2/GCS_Mavlink.cpp
index 4e32e06b3d..29ef7eba25 100644
--- a/APMrover2/GCS_Mavlink.cpp
+++ b/APMrover2/GCS_Mavlink.cpp
@@ -491,8 +491,11 @@ void GCS_MAVLINK_Rover::handle_change_alt_request(AP_Mission::Mission_Command &c
 MAV_RESULT GCS_MAVLINK_Rover::_handle_command_preflight_calibration(const mavlink_command_long_t &packet)
 {
     if (is_equal(packet.param4, 1.0f)) {
-        rover.trim_radio();
-        return MAV_RESULT_ACCEPTED;
+        if (rover.trim_radio()) {
+            return MAV_RESULT_ACCEPTED;
+        } else {
+            return MAV_RESULT_FAILED;
+        }
     }
 
     return GCS_MAVLINK::_handle_command_preflight_calibration(packet);
diff --git a/APMrover2/Rover.h b/APMrover2/Rover.h
index 3910be1fca..f94b27d843 100644
--- a/APMrover2/Rover.h
+++ b/APMrover2/Rover.h
@@ -503,8 +503,7 @@ private:
     void rudder_arm_disarm_check();
     void read_radio();
     void control_failsafe(uint16_t pwm);
-    void trim_control_surfaces();
-    void trim_radio();
+    bool trim_radio();
 
     // sensors.cpp
     void init_compass(void);
diff --git a/APMrover2/radio.cpp b/APMrover2/radio.cpp
index 5dc59a0fc3..0137e836bb 100644
--- a/APMrover2/radio.cpp
+++ b/APMrover2/radio.cpp
@@ -137,22 +137,20 @@ void Rover::control_failsafe(uint16_t pwm)
     }
 }
 
-void Rover::trim_control_surfaces()
+bool Rover::trim_radio()
 {
-    read_radio();
+    if (failsafe.bits & FAILSAFE_EVENT_RC) {
+        // can't trim without valid input
+        return false;
+    }
+
     // Store control surface trim values
     // ---------------------------------
     if ((channel_steer->get_radio_in() > 1400) && (channel_steer->get_radio_in() < 1600)) {
-        channel_steer->set_radio_trim(channel_steer->get_radio_in());
-        // save to eeprom
-        channel_steer->save_eeprom();
+        channel_steer->set_and_save_radio_trim(channel_steer->get_radio_in());
+    } else {
+        return false;
     }
-}
 
-void Rover::trim_radio()
-{
-    for (uint8_t y = 0; y < 30; y++) {
-        read_radio();
-    }
-    trim_control_surfaces();
+    return true;
 }