diff --git a/libraries/AP_Motors/AP_MotorsHeli.cpp b/libraries/AP_Motors/AP_MotorsHeli.cpp
index 1a48e8cf23..7282d30f13 100644
--- a/libraries/AP_Motors/AP_MotorsHeli.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli.cpp
@@ -52,7 +52,7 @@ const AP_Param::GroupInfo AP_MotorsHeli::var_info[] = {
 
     // @Param: COL_MID
     // @DisplayName: Collective Pitch Mid-Point
-    // @Description: Swash servo position corresponding to zero collective pitch (or zero lift for Assymetrical blades)
+    // @Description: Swash servo position corresponding to zero collective pitch (or zero lift for Asymmetrical blades)
     // @Range: 1000 2000
     // @Units: PWM
     // @Increment: 1
diff --git a/libraries/AP_Motors/AP_MotorsHeli.h b/libraries/AP_Motors/AP_MotorsHeli.h
index 6ef283249e..b521994ca1 100644
--- a/libraries/AP_Motors/AP_MotorsHeli.h
+++ b/libraries/AP_Motors/AP_MotorsHeli.h
@@ -186,7 +186,7 @@ protected:
     AP_Int16        _cyclic_max;                // Maximum cyclic angle of the swash plate in centi-degrees
     AP_Int16        _collective_min;            // Lowest possible servo position for the swashplate
     AP_Int16        _collective_max;            // Highest possible servo position for the swashplate
-    AP_Int16        _collective_mid;            // Swash servo position corresponding to zero collective pitch (or zero lift for Assymetrical blades)
+    AP_Int16        _collective_mid;            // Swash servo position corresponding to zero collective pitch (or zero lift for Asymmetrical blades)
     AP_Int8         _servo_mode;              // Pass radio inputs directly to servos during set-up through mission planner
     AP_Int16        _rsc_setpoint;              // rotor speed when RSC mode is set to is enabledv
     AP_Int8         _rsc_mode;                  // Which main rotor ESC control mode is active
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Single.cpp b/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
index a76c057a09..20b286c221 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
@@ -300,7 +300,7 @@ void AP_MotorsHeli_Single::calculate_roll_pitch_collective_factors()
         _collectiveFactor[CH_2] = 1;
         _collectiveFactor[CH_3] = 1;
 
-    }else{              //H1 Swashplate, keep servo outputs seperated
+    }else{              //H1 Swashplate, keep servo outputs separated
 
         // roll factors
         _rollFactor[CH_1] = 1;