diff --git a/libraries/AP_Motors/AP_MotorsCoax.cpp b/libraries/AP_Motors/AP_MotorsCoax.cpp
index d0cf7ace4b..dad88a9d35 100644
--- a/libraries/AP_Motors/AP_MotorsCoax.cpp
+++ b/libraries/AP_Motors/AP_MotorsCoax.cpp
@@ -38,13 +38,13 @@ void AP_MotorsCoax::init(motor_frame_class frame_class, motor_frame_type frame_t
     }
 
     // record successful initialisation if what we setup was the desired frame_class
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_COAX);
+    set_initialised_ok(frame_class == MOTOR_FRAME_COAX);
 }
 
 // set frame class (i.e. quad, hexa, heli) and type (i.e. x, plus)
 void AP_MotorsCoax::set_frame_class_and_type(motor_frame_class frame_class, motor_frame_type frame_type)
 {
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_COAX);
+    set_initialised_ok(frame_class == MOTOR_FRAME_COAX);
 }
 
 // set update rate to motors - a value in hertz
diff --git a/libraries/AP_Motors/AP_MotorsHeli.cpp b/libraries/AP_Motors/AP_MotorsHeli.cpp
index a528583f8e..783ba83460 100644
--- a/libraries/AP_Motors/AP_MotorsHeli.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli.cpp
@@ -132,7 +132,7 @@ void AP_MotorsHeli::init(motor_frame_class frame_class, motor_frame_type frame_t
     calculate_scalars();
 
     // record successful initialisation if what we setup was the desired frame_class
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_HELI);
+    set_initialised_ok(frame_class == MOTOR_FRAME_HELI);
 
     // set flag to true so targets are initialized once aircraft is armed for first time
     _heliflags.init_targets_on_arming = true;
@@ -142,7 +142,7 @@ void AP_MotorsHeli::init(motor_frame_class frame_class, motor_frame_type frame_t
 // set frame class (i.e. quad, hexa, heli) and type (i.e. x, plus)
 void AP_MotorsHeli::set_frame_class_and_type(motor_frame_class frame_class, motor_frame_type frame_type)
 {
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_HELI);
+    set_initialised_ok(frame_class == MOTOR_FRAME_HELI);
 }
 
 // output_min - sets servos to neutral point with motors stopped
@@ -170,12 +170,11 @@ void AP_MotorsHeli::output()
     // run spool logic
     output_logic();
 
-    if (_flags.armed) {
+    if (armed()) {
         // block servo_test from happening at disarm
         _servo_test_cycle_counter = 0;
-        
         calculate_armed_scalars();
-        if (!_flags.interlock) {
+        if (!get_interlock()) {
             output_armed_zero_throttle();
         } else {
             output_armed_stabilizing();
@@ -285,8 +284,8 @@ void AP_MotorsHeli::output_disarmed()
 void AP_MotorsHeli::output_logic()
 {
     // force desired and current spool mode if disarmed and armed with interlock enabled
-    if (_flags.armed) {
-        if (!_flags.interlock) {
+    if (armed()) {
+        if (!get_interlock()) {
             _spool_desired = DesiredSpoolState::GROUND_IDLE;
         } else {
             _heliflags.init_targets_on_arming = false;
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp b/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp
index 0c4edd1299..a79b8e9443 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp
@@ -223,7 +223,7 @@ void AP_MotorsHeli_Dual::set_update_rate( uint16_t speed_hz )
 // init_outputs
 bool AP_MotorsHeli_Dual::init_outputs()
 {
-    if (!_flags.initialised_ok) {
+    if (!initialised_ok()) {
         // make sure 6 output channels are mapped
         for (uint8_t i=0; i<AP_MOTORS_HELI_DUAL_NUM_SWASHPLATE_SERVOS; i++) {
             add_motor_num(CH_1+i);
@@ -258,7 +258,7 @@ bool AP_MotorsHeli_Dual::init_outputs()
         reset_swash_servo(SRV_Channels::get_motor_function(7));
     }
 
-    _flags.initialised_ok = true;
+    set_initialised_ok(true);
 
     return true;
 }
@@ -335,7 +335,7 @@ void AP_MotorsHeli_Dual::calculate_armed_scalars()
         gcs().send_text(MAV_SEVERITY_CRITICAL, "RSC control mode change failed");
     }
     // saves rsc mode parameter when disarmed if it had been reset while armed
-    if (_heliflags.save_rsc_mode && !_flags.armed) {
+    if (_heliflags.save_rsc_mode && !armed()) {
         _main_rotor._rsc_mode.save();
         _heliflags.save_rsc_mode = false;
     }
@@ -606,7 +606,7 @@ void AP_MotorsHeli_Dual::move_actuators(float roll_out, float pitch_out, float c
 
 void AP_MotorsHeli_Dual::output_to_motors()
 {
-    if (!_flags.initialised_ok) {
+    if (!initialised_ok()) {
         return;
     }
     // actually move the servos.  PWM is sent based on nominal 1500 center.  servo output shifts center based on trim value.
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp b/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp
index 25a99c6749..d8be36c1f1 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp
@@ -48,7 +48,7 @@ void AP_MotorsHeli_Quad::set_update_rate( uint16_t speed_hz )
 // init_outputs
 bool AP_MotorsHeli_Quad::init_outputs()
 {
-    if (_flags.initialised_ok) {
+    if (initialised_ok()) {
         return true;
     }
 
@@ -67,7 +67,7 @@ bool AP_MotorsHeli_Quad::init_outputs()
         _main_rotor.set_ext_gov_arot_bail(0);
     }
 
-    _flags.initialised_ok = true;
+    set_initialised_ok(true);
 
     return true;
 }
@@ -123,7 +123,7 @@ void AP_MotorsHeli_Quad::calculate_armed_scalars()
         _heliflags.save_rsc_mode = true;
     }
     // saves rsc mode parameter when disarmed if it had been reset while armed
-    if (_heliflags.save_rsc_mode && !_flags.armed) {
+    if (_heliflags.save_rsc_mode && !armed()) {
         _main_rotor._rsc_mode.save();
         _heliflags.save_rsc_mode = false;
     }
@@ -305,7 +305,7 @@ void AP_MotorsHeli_Quad::move_actuators(float roll_out, float pitch_out, float c
 
 void AP_MotorsHeli_Quad::output_to_motors()
 {
-    if (!_flags.initialised_ok) {
+    if (!initialised_ok()) {
         return;
     }
 
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Single.cpp b/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
index 5474922cc6..2275dc0699 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
@@ -161,7 +161,7 @@ void AP_MotorsHeli_Single::set_update_rate( uint16_t speed_hz )
 // init_outputs - initialise Servo/PWM ranges and endpoints
 bool AP_MotorsHeli_Single::init_outputs()
 {
-    if (!_flags.initialised_ok) {
+    if (!initialised_ok()) {
         // map primary swash servos
         for (uint8_t i=0; i<AP_MOTORS_HELI_SINGLE_NUM_SWASHPLATE_SERVOS; i++) {
             add_motor_num(CH_1+i);
@@ -215,7 +215,7 @@ bool AP_MotorsHeli_Single::init_outputs()
     // yaw servo is an angle from -4500 to 4500
     SRV_Channels::set_angle(SRV_Channel::k_motor4, YAW_SERVO_MAX_ANGLE);
 
-    _flags.initialised_ok = true;
+    set_initialised_ok(true);
 
     return true;
 }
@@ -294,7 +294,7 @@ void AP_MotorsHeli_Single::calculate_armed_scalars()
         _heliflags.save_rsc_mode = true;
     }
     // saves rsc mode parameter when disarmed if it had been reset while armed
-    if (_heliflags.save_rsc_mode && !_flags.armed) {
+    if (_heliflags.save_rsc_mode && !armed()) {
         _main_rotor._rsc_mode.save();
         _heliflags.save_rsc_mode = false;
     }
@@ -503,7 +503,7 @@ void AP_MotorsHeli_Single::move_yaw(float yaw_out)
 
 void AP_MotorsHeli_Single::output_to_motors()
 {
-    if (!_flags.initialised_ok) {
+    if (!initialised_ok()) {
         return;
     }
 
diff --git a/libraries/AP_Motors/AP_MotorsMatrix.cpp b/libraries/AP_Motors/AP_MotorsMatrix.cpp
index 705d86ae5c..08aea5e80c 100644
--- a/libraries/AP_Motors/AP_MotorsMatrix.cpp
+++ b/libraries/AP_Motors/AP_MotorsMatrix.cpp
@@ -883,7 +883,7 @@ void AP_MotorsMatrix::setup_motors(motor_frame_class frame_class, motor_frame_ty
     // normalise factors to magnitude 0.5
     normalise_rpy_factors();
 
-    _flags.initialised_ok = success;
+    set_initialised_ok(success);
 }
 
 // normalizes the roll, pitch and yaw factors so maximum magnitude is 0.5
diff --git a/libraries/AP_Motors/AP_MotorsMulticopter.cpp b/libraries/AP_Motors/AP_MotorsMulticopter.cpp
index 4d82ada853..527ed7952c 100644
--- a/libraries/AP_Motors/AP_MotorsMulticopter.cpp
+++ b/libraries/AP_Motors/AP_MotorsMulticopter.cpp
@@ -307,7 +307,7 @@ float AP_MotorsMulticopter::get_current_limit_max_throttle()
     float _batt_current;
 
     if (_batt_current_max <= 0 || // return maximum if current limiting is disabled
-        !_flags.armed || // remove throttle limit if disarmed
+        !armed() || // remove throttle limit if disarmed
         !battery.current_amps(_batt_current, _batt_idx)) { // no current monitoring is available
         _throttle_limit = 1.0f;
         return 1.0f;
@@ -533,7 +533,7 @@ void AP_MotorsMulticopter::update_throttle_hover(float dt)
 // run spool logic
 void AP_MotorsMulticopter::output_logic()
 {
-    if (_flags.armed) {
+    if (armed()) {
         if (_disarm_disable_pwm && (_disarm_safe_timer < _safe_time)) {
             _disarm_safe_timer += 1.0f/_loop_rate;
         } else {
@@ -544,7 +544,7 @@ void AP_MotorsMulticopter::output_logic()
     }
 
     // force desired and current spool mode if disarmed or not interlocked
-    if (!_flags.armed || !_flags.interlock) {
+    if (!armed() || !get_interlock()) {
         _spool_desired = DesiredSpoolState::SHUT_DOWN;
         _spool_state = SpoolState::SHUT_DOWN;
     }
diff --git a/libraries/AP_Motors/AP_MotorsSingle.cpp b/libraries/AP_Motors/AP_MotorsSingle.cpp
index bdcc91bc71..b2db48f370 100644
--- a/libraries/AP_Motors/AP_MotorsSingle.cpp
+++ b/libraries/AP_Motors/AP_MotorsSingle.cpp
@@ -38,7 +38,7 @@ void AP_MotorsSingle::init(motor_frame_class frame_class, motor_frame_type frame
     }
 
     // record successful initialisation if what we setup was the desired frame_class
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_SINGLE);
+    set_initialised_ok(frame_class == MOTOR_FRAME_SINGLE);
 }
 
 // set frame class (i.e. quad, hexa, heli) and type (i.e. x, plus)
@@ -61,7 +61,7 @@ void AP_MotorsSingle::set_update_rate(uint16_t speed_hz)
 
 void AP_MotorsSingle::output_to_motors()
 {
-    if (!_flags.initialised_ok) {
+    if (!initialised_ok()) {
         return;
     }
     switch (_spool_state) {
diff --git a/libraries/AP_Motors/AP_MotorsTailsitter.cpp b/libraries/AP_Motors/AP_MotorsTailsitter.cpp
index 2a072c15f0..bb4b70d084 100644
--- a/libraries/AP_Motors/AP_MotorsTailsitter.cpp
+++ b/libraries/AP_Motors/AP_MotorsTailsitter.cpp
@@ -54,7 +54,7 @@ void AP_MotorsTailsitter::init(motor_frame_class frame_class, motor_frame_type f
     SRV_Channels::set_angle(SRV_Channel::k_tiltMotorLeft, SERVO_OUTPUT_RANGE);
 
     // record successful initialisation if what we setup was the desired frame_class
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_TAILSITTER);
+    set_initialised_ok(frame_class == MOTOR_FRAME_TAILSITTER);
 }
 
 
@@ -78,7 +78,7 @@ void AP_MotorsTailsitter::set_update_rate(uint16_t speed_hz)
 
 void AP_MotorsTailsitter::output_to_motors()
 {
-    if (!_flags.initialised_ok) {
+    if (!initialised_ok()) {
         return;
     }
 
diff --git a/libraries/AP_Motors/AP_MotorsTri.cpp b/libraries/AP_Motors/AP_MotorsTri.cpp
index 721f752f4f..5eda792826 100644
--- a/libraries/AP_Motors/AP_MotorsTri.cpp
+++ b/libraries/AP_Motors/AP_MotorsTri.cpp
@@ -55,7 +55,7 @@ void AP_MotorsTri::init(motor_frame_class frame_class, motor_frame_type frame_ty
     }
 
     // record successful initialisation if what we setup was the desired frame_class
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_TRI);
+    set_initialised_ok(frame_class == MOTOR_FRAME_TRI);
 }
 
 // set frame class (i.e. quad, hexa, heli) and type (i.e. x, plus)
@@ -68,7 +68,7 @@ void AP_MotorsTri::set_frame_class_and_type(motor_frame_class frame_class, motor
         _pitch_reversed = false;
     }
 
-    _flags.initialised_ok = (frame_class == MOTOR_FRAME_TRI) && SRV_Channels::function_assigned(SRV_Channel::k_motor7);
+    set_initialised_ok((frame_class == MOTOR_FRAME_TRI) && SRV_Channels::function_assigned(SRV_Channel::k_motor7));
 }
 
 // set update rate to motors - a value in hertz
diff --git a/libraries/AP_Motors/AP_Motors_Class.cpp b/libraries/AP_Motors/AP_Motors_Class.cpp
index db834fb9f7..c0215824e8 100644
--- a/libraries/AP_Motors/AP_Motors_Class.cpp
+++ b/libraries/AP_Motors/AP_Motors_Class.cpp
@@ -50,8 +50,8 @@ AP_Motors::AP_Motors(uint16_t loop_rate, uint16_t speed_hz) :
 
 void AP_Motors::armed(bool arm)
 {
-    if (_flags.armed != arm) {
-        _flags.armed = arm;
+    if (_armed != arm) {
+        _armed = arm;
         AP_Notify::flags.armed = arm;
         if (!arm) {
             save_params_on_disarm();
@@ -61,7 +61,7 @@ void AP_Motors::armed(bool arm)
 
 void AP_Motors::set_desired_spool_state(DesiredSpoolState spool)
 {
-    if (_flags.armed || (spool == DesiredSpoolState::SHUT_DOWN)) {
+    if (_armed || (spool == DesiredSpoolState::SHUT_DOWN)) {
         _spool_desired = spool;
     }
 };
diff --git a/libraries/AP_Motors/AP_Motors_Class.h b/libraries/AP_Motors/AP_Motors_Class.h
index 6d15195924..de110d5519 100644
--- a/libraries/AP_Motors/AP_Motors_Class.h
+++ b/libraries/AP_Motors/AP_Motors_Class.h
@@ -71,17 +71,18 @@ public:
     static AP_Motors    *get_singleton(void) { return _singleton; }
 
     // check initialisation succeeded
-    bool                initialised_ok() const { return _flags.initialised_ok; }
+    bool                initialised_ok() const { return _initialised_ok; }
+    void                set_initialised_ok(bool val) { _initialised_ok = val; }
 
     // arm, disarm or check status status of motors
-    bool                armed() const { return _flags.armed; }
+    bool                armed() const { return _armed; }
     void                armed(bool arm);
 
     // set motor interlock status
-    void                set_interlock(bool set) { _flags.interlock = set;}
+    void                set_interlock(bool set) { _interlock = set;}
 
     // get motor interlock status.  true means motors run, false motors don't run
-    bool                get_interlock() const { return _flags.interlock; }
+    bool                get_interlock() const { return _interlock; }
 
     // set_roll, set_pitch, set_yaw, set_throttle
     void                set_roll(float roll_in) { _roll_in = roll_in; };        // range -1 ~ +1
@@ -198,7 +199,7 @@ public:
                     PWM_TYPE_DSHOT600   = 6,
                     PWM_TYPE_DSHOT1200  = 7};
     pwm_type            get_pwm_type(void) const { return (pwm_type)_pwm_type.get(); }
-    
+
 protected:
     // output functions that should be overloaded by child classes
     virtual void        output_armed_stabilizing() = 0;
@@ -216,13 +217,6 @@ protected:
     // save parameters as part of disarming
     virtual void save_params_on_disarm() {}
 
-    // flag bitmask
-    struct AP_Motors_flags {
-        uint8_t armed              : 1;    // 0 if disarmed, 1 if armed
-        uint8_t interlock          : 1;    // 1 if the motor interlock is enabled (i.e. motors run), 0 if disabled (motors don't run)
-        uint8_t initialised_ok     : 1;    // 1 if initialisation was successful
-    } _flags;
-
     // internal variables
     uint16_t            _loop_rate;                 // rate in Hz at which output() function is called (normally 400hz)
     uint16_t            _speed_hz;                  // speed in hz to send updates to motors
@@ -261,7 +255,13 @@ protected:
     float               _thrust_boost_ratio;    // choice between highest and second highest motor output for output mixing (0 ~ 1). Zero is normal operation
 
 private:
+
+    bool _armed;             // 0 if disarmed, 1 if armed
+    bool _interlock;         // 1 if the motor interlock is enabled (i.e. motors run), 0 if disabled (motors don't run)
+    bool _initialised_ok;    // 1 if initialisation was successful
+
     static AP_Motors *_singleton;
+
 };
 
 namespace AP {