diff --git a/ArduCopter/ArduCopter.pde b/ArduCopter/ArduCopter.pde
index f390c7be57..e9cc426629 100644
--- a/ArduCopter/ArduCopter.pde
+++ b/ArduCopter/ArduCopter.pde
@@ -1119,7 +1119,6 @@ void update_throttle_mode(void)
 
 				// clear the new data flag
 				invalid_throttle = false;
-				Serial.printf("nt %d\n",nav_throttle);
 			}
 
 			// apply throttle control at 200 hz
diff --git a/ArduCopter/Attitude.pde b/ArduCopter/Attitude.pde
index 516d9b2201..97cebe366c 100644
--- a/ArduCopter/Attitude.pde
+++ b/ArduCopter/Attitude.pde
@@ -104,8 +104,6 @@ get_nav_throttle(long z_error, int target_speed)
 	float delta_throttle	= (float)(timer - throttle_timer)/1000.0;
 	throttle_timer    		= timer;
 
-	Serial.printf("tt %ld, dt %1.4f ", throttle_timer, delta_throttle);
-
 	return g.pi_throttle.get_pi(rate_error, delta_throttle);
 }