diff --git a/ArduCopter/GCS_Mavlink.pde b/ArduCopter/GCS_Mavlink.pde
index f909fcf43f..e843dd9ed2 100644
--- a/ArduCopter/GCS_Mavlink.pde
+++ b/ArduCopter/GCS_Mavlink.pde
@@ -1177,7 +1177,7 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
             } 
             if (packet.param3 == 1) {
 #if HIL_MODE != HIL_MODE_ATTITUDE
-                init_barometer();
+                init_barometer(false);                      // fast barometer calibratoin
 #endif
             }
             if (packet.param4 == 1) {
diff --git a/ArduCopter/motors.pde b/ArduCopter/motors.pde
index d35796e336..4632b8c408 100644
--- a/ArduCopter/motors.pde
+++ b/ArduCopter/motors.pde
@@ -169,10 +169,8 @@ static void init_arm_motors()
     }
 
 #if HIL_MODE != HIL_MODE_ATTITUDE
-    // read Baro pressure at ground -
-    // this resets Baro for more accuracy
-    //-----------------------------------
-    init_barometer();
+    // fast baro calibration to reset ground pressure
+    init_barometer(false);
 #endif
 
     // go back to normal AHRS gains
diff --git a/ArduCopter/sensors.pde b/ArduCopter/sensors.pde
index e580e02d61..839dc78c8d 100644
--- a/ArduCopter/sensors.pde
+++ b/ArduCopter/sensors.pde
@@ -14,10 +14,14 @@ static void init_sonar(void)
 }
  #endif
 
-static void init_barometer(void)
+static void init_barometer(bool full_calibration)
 {
     gcs_send_text_P(SEVERITY_LOW, PSTR("Calibrating barometer"));
-    barometer.calibrate();
+    if (full_calibration) {
+        barometer.calibrate();
+    }else{
+        barometer.update_calibration();
+    }
     gcs_send_text_P(SEVERITY_LOW, PSTR("barometer calibration complete"));
 }
 
diff --git a/ArduCopter/system.pde b/ArduCopter/system.pde
index f6022187d7..534d083b53 100644
--- a/ArduCopter/system.pde
+++ b/ArduCopter/system.pde
@@ -263,7 +263,7 @@ static void init_ardupilot()
 #if HIL_MODE != HIL_MODE_ATTITUDE
     // read Baro pressure at ground
     //-----------------------------
-    init_barometer();
+    init_barometer(true);
 #endif
 
     // initialise sonar
diff --git a/ArduCopter/test.pde b/ArduCopter/test.pde
index 6305d40b71..5b45c81675 100644
--- a/ArduCopter/test.pde
+++ b/ArduCopter/test.pde
@@ -64,7 +64,7 @@ test_baro(uint8_t argc, const Menu::arg *argv)
 {
     int32_t alt;
     print_hit_enter();
-    init_barometer();
+    init_barometer(true);
 
     while(1) {
         delay(100);