diff --git a/ArduCopter/motors.pde b/ArduCopter/motors.pde
index 007c9dd316..7a427e6903 100644
--- a/ArduCopter/motors.pde
+++ b/ArduCopter/motors.pde
@@ -65,6 +65,11 @@ static void arm_motors()
 
 static void init_arm_motors()
 {
+	// Flag used to track if we have armed the motors the first time.
+	// This is used to decide if we should run the ground_start routine
+	// which calibrates the IMU
+	static bool did_ground_start = false;
+
 	//Serial.printf("\nARM\n");
     #if HIL_MODE != HIL_MODE_DISABLED || defined(DESKTOP_BUILD)
 	gcs_send_text_P(SEVERITY_HIGH, PSTR("ARMING MOTORS"));
@@ -116,6 +121,9 @@ static void init_disarm_motors()
 	motor_armed 	= false;
 	compass.save_offsets();
 
+	// we are not in the air
+	takeoff_complete = false;
+
 	#if PIEZO_ARMING == 1
 	piezo_beep();
 	#endif