diff --git a/libraries/AP_Motors/AP_MotorsHeli.cpp b/libraries/AP_Motors/AP_MotorsHeli.cpp
index f372acafee..e9216662db 100644
--- a/libraries/AP_Motors/AP_MotorsHeli.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli.cpp
@@ -331,7 +331,7 @@ void AP_MotorsHeli::output_test()
 }
 
 // allow_arming - returns true if main rotor is spinning and it is ok to arm
-bool AP_MotorsHeli::allow_arming()
+bool AP_MotorsHeli::allow_arming() const
 {
     // ensure main rotor has started
     if (_rsc_mode != AP_MOTORS_HELI_RSC_MODE_NONE && _servo_rsc->control_in > 0) {
@@ -349,7 +349,7 @@ void AP_MotorsHeli::set_desired_rotor_speed(int16_t desired_speed)
 }
 
 // return true if the main rotor is up to speed
-bool AP_MotorsHeli::motor_runup_complete()
+bool AP_MotorsHeli::motor_runup_complete() const
 {
     // if we have no control of motors, assume pilot has spun them up
     if (_rsc_mode == AP_MOTORS_HELI_RSC_MODE_NONE) {
diff --git a/libraries/AP_Motors/AP_MotorsHeli.h b/libraries/AP_Motors/AP_MotorsHeli.h
index 1f89d81a28..682a6254b8 100644
--- a/libraries/AP_Motors/AP_MotorsHeli.h
+++ b/libraries/AP_Motors/AP_MotorsHeli.h
@@ -146,44 +146,44 @@ public:
     //
 
     // allow_arming - returns true if main rotor is spinning and it is ok to arm
-    bool allow_arming();
+    bool allow_arming() const;
 
     // _tail_type - returns the tail type (servo, servo with ext gyro, direct drive var pitch, direct drive fixed pitch)
-    int16_t tail_type() { return _tail_type; }
+    int16_t tail_type() const { return _tail_type; }
 
     // ext_gyro_gain - gets and sets external gyro gain as a pwm (1000~2000)
-    int16_t ext_gyro_gain() { return _ext_gyro_gain; }
+    int16_t ext_gyro_gain() const { return _ext_gyro_gain; }
     void ext_gyro_gain(int16_t pwm) { _ext_gyro_gain = pwm; }
 
     // has_flybar - returns true if we have a mechical flybar
-    bool has_flybar() { return _flybar_mode; }
+    bool has_flybar() const { return _flybar_mode; }
 
     // get_collective_mid - returns collective mid position as a number from 0 ~ 1000
-    int16_t get_collective_mid() { return  _collective_mid; }
+    int16_t get_collective_mid() const { return  _collective_mid; }
 
     // get_collective_out - returns collective position from last output as a number from 0 ~ 1000
-    int16_t get_collective_out() { return _collective_out; }
+    int16_t get_collective_out() const { return _collective_out; }
 
     // set_collective_for_landing - limits collective from going too low if we know we are landed
     void set_collective_for_landing(bool landing) { _heliflags.landing_collective = landing; }
 
     // get_rsc_mode - gets the rotor speed control method (AP_MOTORS_HELI_RSC_MODE_NONE, AP_MOTORS_HELI_RSC_MODE_CH8_PASSTHROUGH or AP_MOTORS_HELI_RSC_MODE_SETPOINT)
-    uint8_t get_rsc_mode() { return _rsc_mode; }
+    uint8_t get_rsc_mode() const { return _rsc_mode; }
 
     // get_rsc_setpoint - gets contents of _rsc_setpoint parameter (0~1000)
-    int16_t get_rsc_setpoint() { return _rsc_setpoint; }
+    int16_t get_rsc_setpoint() const { return _rsc_setpoint; }
 
     // set_desired_rotor_speed - sets target rotor speed as a number from 0 ~ 1000
     void set_desired_rotor_speed(int16_t desired_speed);
 
     // return true if the main rotor is up to speed
-    bool motor_runup_complete();
+    bool motor_runup_complete() const;
 
     // recalc_scalers - recalculates various scalers used.  Should be called at about 1hz to allow users to see effect of changing parameters
     void recalc_scalers();
 
     // get_phase_angle - returns phase angle
-    int16_t get_phase_angle() { return _phase_angle; }
+    int16_t get_phase_angle() const { return _phase_angle; }
 
     // var_info for holding Parameter information
     static const struct AP_Param::GroupInfo var_info[];