diff --git a/libraries/RC_Channel/RC_Channel.cpp b/libraries/RC_Channel/RC_Channel.cpp
index bb0285fe92..31738a25d7 100644
--- a/libraries/RC_Channel/RC_Channel.cpp
+++ b/libraries/RC_Channel/RC_Channel.cpp
@@ -396,7 +396,7 @@ float RC_Channel::stick_mixing(const float servo_in)
 }
 
 //
-// support for auxillary switches:
+// support for auxiliary switches:
 //
 
 void RC_Channel::reset_mode_switch()
@@ -463,7 +463,7 @@ bool RC_Channel::debounce_completed(int8_t position)
 }
 
 //
-// support for auxillary switches:
+// support for auxiliary switches:
 //
 
 // init_aux_switch_function - initialize aux functions
@@ -909,7 +909,7 @@ bool RC_Channel::run_aux_function(aux_func_t ch_option, AuxSwitchPos pos, AuxFun
     // @Field: TimeUS: Time since system startup
     // @Field: function: ID of triggered function
     // @Field: pos: switch position when function triggered
-    // @Field: source: source of auxillary function invocation
+    // @Field: source: source of auxiliary function invocation
     // @Field: result: true if function was successful
     AP::logger().Write(
         "AUXF",
diff --git a/libraries/RC_Channel/RC_Channel.h b/libraries/RC_Channel/RC_Channel.h
index f06fecccbe..5da864f7ec 100644
--- a/libraries/RC_Channel/RC_Channel.h
+++ b/libraries/RC_Channel/RC_Channel.h
@@ -249,7 +249,7 @@ public:
     };
     typedef enum AUX_FUNC aux_func_t;
 
-    // auxillary switch handling (n.b.: we store this as 2-bits!):
+    // auxiliary switch handling (n.b.: we store this as 2-bits!):
     enum class AuxSwitchPos : uint8_t {
         LOW,       // indicates auxiliary switch is in the low position (pwm <1200)
         MIDDLE,    // indicates auxiliary switch is in the middle position (pwm >1200, <1800)
@@ -546,7 +546,7 @@ public:
     uint32_t last_input_ms() const { return last_update_ms; };
 
     // method for other parts of the system (e.g. Button and mavlink)
-    // to trigger auxillary functions
+    // to trigger auxiliary functions
     bool run_aux_function(RC_Channel::AUX_FUNC ch_option, RC_Channel::AuxSwitchPos pos, RC_Channel::AuxFuncTriggerSource source) {
         return rc_channel(0)->run_aux_function(ch_option, pos, source);
     }
diff --git a/libraries/RC_Channel/RC_Channels.cpp b/libraries/RC_Channel/RC_Channels.cpp
index 4a20233910..328a183203 100644
--- a/libraries/RC_Channel/RC_Channels.cpp
+++ b/libraries/RC_Channel/RC_Channels.cpp
@@ -148,7 +148,7 @@ bool RC_Channels::receiver_bind(const int dsmMode)
 }
 
 
-// support for auxillary switches:
+// support for auxiliary switches:
 // read_aux_switches - checks aux switch positions and invokes configured actions
 void RC_Channels::read_aux_all()
 {