diff --git a/ArduCopter/APM_Config_mavlink_hil.h b/ArduCopter/APM_Config_mavlink_hil.h
index dad432892d..9c5d37c78a 100644
--- a/ArduCopter/APM_Config_mavlink_hil.h
+++ b/ArduCopter/APM_Config_mavlink_hil.h
@@ -4,7 +4,7 @@
 // 1. HIL_MODE_SENSORS: full sensor simulation
 #define HIL_MODE            HIL_MODE_SENSORS
 
-// HIL_PORT SELCTION
+// HIL_PORT SELECTION
 //
 // PORT 1
 // If you would like to run telemetry communications for a groundstation
diff --git a/ArduCopter/Copter.h b/ArduCopter/Copter.h
index 5cd234b26d..ce1c67a2c7 100644
--- a/ArduCopter/Copter.h
+++ b/ArduCopter/Copter.h
@@ -261,7 +261,7 @@ private:
     SITL::SITL sitl;
 #endif
 
-    // Arming/Disarming mangement class
+    // Arming/Disarming management class
     AP_Arming_Copter arming;
 
     // Optical flow sensor
diff --git a/ArduCopter/GCS_Mavlink.cpp b/ArduCopter/GCS_Mavlink.cpp
index dfbcd9e149..3b4848e927 100644
--- a/ArduCopter/GCS_Mavlink.cpp
+++ b/ArduCopter/GCS_Mavlink.cpp
@@ -1298,7 +1298,7 @@ bool GCS_MAVLINK_Copter::set_mode(const uint8_t mode)
 float GCS_MAVLINK_Copter::vfr_hud_alt() const
 {
     if (copter.g2.dev_options.get() & DevOptionVFR_HUDRelativeAlt) {
-        // compatability option for older mavlink-aware devices that
+        // compatibility option for older mavlink-aware devices that
         // assume Copter returns a relative altitude in VFR_HUD.alt
         return copter.current_loc.alt / 100.0f;
     }
diff --git a/ArduCopter/Parameters.cpp b/ArduCopter/Parameters.cpp
index 79d381ed31..c10a22c449 100644
--- a/ArduCopter/Parameters.cpp
+++ b/ArduCopter/Parameters.cpp
@@ -1316,7 +1316,7 @@ void Copter::convert_tradheli_parameters(void)
             { Parameters::k_param_motors, 19, AP_PARAM_INT8, "H_SW_COL_DIR" },
         };
 
-        // convert single heli paramters without scaling
+        // convert single heli parameters without scaling
         uint8_t table_size = ARRAY_SIZE(singleheli_conversion_info);
         for (uint8_t i=0; i<table_size; i++) {
             AP_Param::convert_old_parameter(&singleheli_conversion_info[i], 1.0f);
diff --git a/ArduCopter/Parameters.h b/ArduCopter/Parameters.h
index a9d248f410..8b937c2362 100644
--- a/ArduCopter/Parameters.h
+++ b/ArduCopter/Parameters.h
@@ -259,7 +259,7 @@ public:
         k_param_camera_mount2,      // deprecated
 
         //
-        // Batery monitoring parameters
+        // Battery monitoring parameters
         //
         k_param_battery_volt_pin = 168, // deprecated - can be deleted
         k_param_battery_curr_pin,   // 169 deprecated - can be deleted
diff --git a/ArduCopter/RC_Channel.cpp b/ArduCopter/RC_Channel.cpp
index 4683981fb2..c552caa5b4 100644
--- a/ArduCopter/RC_Channel.cpp
+++ b/ArduCopter/RC_Channel.cpp
@@ -2,7 +2,7 @@
 
 #include "RC_Channel.h"
 
-// defining these two macros and including the RC_Channels_VarInfo header defines the parmaeter information common to all vehicle types
+// defining these two macros and including the RC_Channels_VarInfo header defines the parameter information common to all vehicle types
 #define RC_CHANNELS_SUBCLASS RC_Channels_Copter
 #define RC_CHANNEL_SUBCLASS RC_Channel_Copter
 
@@ -136,7 +136,7 @@ void RC_Channel_Copter::do_aux_function_change_mode(const control_mode_t mode,
     }
 }
 
-// do_aux_function - implement the function invoked by auxillary switches
+// do_aux_function - implement the function invoked by auxiliary switches
 void RC_Channel_Copter::do_aux_function(const aux_func_t ch_option, const aux_switch_pos_t ch_flag)
 {
     switch(ch_option) {
diff --git a/ArduCopter/config.h b/ArduCopter/config.h
index f49d0aa768..a8cba6e81e 100644
--- a/ArduCopter/config.h
+++ b/ArduCopter/config.h
@@ -159,7 +159,7 @@
 
 // Radio failsafe
 #ifndef FS_RADIO_TIMEOUT_MS
- #define FS_RADIO_TIMEOUT_MS            500     // RC Radio Failsafe triggers after 500 miliseconds with No RC Input
+ #define FS_RADIO_TIMEOUT_MS            500     // RC Radio Failsafe triggers after 500 milliseconds with No RC Input
 #endif
 
 // missing terrain data failsafe
diff --git a/ArduCopter/ekf_check.cpp b/ArduCopter/ekf_check.cpp
index 5082bd68fc..6563cdc19d 100644
--- a/ArduCopter/ekf_check.cpp
+++ b/ArduCopter/ekf_check.cpp
@@ -16,7 +16,7 @@
 #endif
 
 ////////////////////////////////////////////////////////////////////////////////
-// EKF_check strucutre
+// EKF_check structure
 ////////////////////////////////////////////////////////////////////////////////
 static struct {
     uint8_t fail_count;         // number of iterations ekf or dcm have been out of tolerances
diff --git a/ArduCopter/mode.cpp b/ArduCopter/mode.cpp
index 836662bd2d..ced681d5bf 100644
--- a/ArduCopter/mode.cpp
+++ b/ArduCopter/mode.cpp
@@ -479,7 +479,7 @@ void Copter::Mode::land_run_horizontal_control()
             // convert pilot input to lean angles
             get_pilot_desired_lean_angles(target_roll, target_pitch, loiter_nav->get_angle_max_cd(), attitude_control->get_althold_lean_angle_max());
 
-            // record if pilot has overriden roll or pitch
+            // record if pilot has overridden roll or pitch
             if (!is_zero(target_roll) || !is_zero(target_pitch)) {
                 if (!ap.land_repo_active) {
                     copter.Log_Write_Event(DATA_LAND_REPO_ACTIVE);
diff --git a/ArduCopter/mode_poshold.cpp b/ArduCopter/mode_poshold.cpp
index ee24324347..927e1e4797 100644
--- a/ArduCopter/mode_poshold.cpp
+++ b/ArduCopter/mode_poshold.cpp
@@ -499,7 +499,7 @@ void Copter::ModePosHold::run()
                         if (!is_zero(target_pitch)) {
                             // init transition to pilot override
                             poshold_pitch_controller_to_pilot_override();
-                            // if roll not overriden switch roll-mode to brake (but be ready to go back to loiter any time)
+                            // if roll not overridden switch roll-mode to brake (but be ready to go back to loiter any time)
                             if (is_zero(target_roll)) {
                                 poshold.roll_mode = POSHOLD_BRAKE_READY_TO_LOITER;
                                 poshold.brake_roll = 0;
diff --git a/ArduCopter/mode_rtl.cpp b/ArduCopter/mode_rtl.cpp
index 4b0fcfc244..7e6e8a479c 100644
--- a/ArduCopter/mode_rtl.cpp
+++ b/ArduCopter/mode_rtl.cpp
@@ -285,7 +285,7 @@ void Copter::ModeRTL::descent_run()
             // convert pilot input to lean angles
             get_pilot_desired_lean_angles(target_roll, target_pitch, loiter_nav->get_angle_max_cd(), attitude_control->get_althold_lean_angle_max());
 
-            // record if pilot has overriden roll or pitch
+            // record if pilot has overridden roll or pitch
             if (!is_zero(target_roll) || !is_zero(target_pitch)) {
                 if (!ap.land_repo_active) {
                     copter.Log_Write_Event(DATA_LAND_REPO_ACTIVE);
diff --git a/ArduCopter/motor_test.cpp b/ArduCopter/motor_test.cpp
index 18e2ef463b..a0138a0e18 100644
--- a/ArduCopter/motor_test.cpp
+++ b/ArduCopter/motor_test.cpp
@@ -82,7 +82,7 @@ void Copter::motor_test_output()
 
         // sanity check throttle values
         if (pwm >= MOTOR_TEST_PWM_MIN && pwm <= MOTOR_TEST_PWM_MAX ) {
-            // turn on motor to specified pwm vlaue
+            // turn on motor to specified pwm value
             motors->output_test_seq(motor_test_seq, pwm);
         } else {
             motor_test_stop();
diff --git a/ArduCopter/motors.cpp b/ArduCopter/motors.cpp
index cdf69a6b5d..03403b4bbc 100644
--- a/ArduCopter/motors.cpp
+++ b/ArduCopter/motors.cpp
@@ -223,7 +223,7 @@ bool Copter::init_arm_motors(const AP_Arming::Method method, const bool do_armin
     // log flight mode in case it was changed while vehicle was disarmed
     logger.Write_Mode(control_mode, control_mode_reason);
 
-    // reenable failsafe
+    // re-enable failsafe
     failsafe_enable();
 
     // perf monitor ignores delay due to arming