diff --git a/libraries/AP_Motors/AP_MotorsCoax.cpp b/libraries/AP_Motors/AP_MotorsCoax.cpp
index f79b4f4c9a..82cc47511d 100644
--- a/libraries/AP_Motors/AP_MotorsCoax.cpp
+++ b/libraries/AP_Motors/AP_MotorsCoax.cpp
@@ -100,12 +100,12 @@ void AP_MotorsCoax::output_to_motors()
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsCoax::get_motor_mask()
+uint32_t AP_MotorsCoax::get_motor_mask()
 {
     uint32_t motor_mask =
         1U << AP_MOTORS_MOT_5 |
         1U << AP_MOTORS_MOT_6;
-    uint16_t mask = motor_mask_to_srv_channel_mask(motor_mask);
+    uint32_t mask = motor_mask_to_srv_channel_mask(motor_mask);
 
     // add parent's mask
     mask |= AP_MotorsMulticopter::get_motor_mask();
diff --git a/libraries/AP_Motors/AP_MotorsCoax.h b/libraries/AP_Motors/AP_MotorsCoax.h
index cd6ab2944f..81ca9551f7 100644
--- a/libraries/AP_Motors/AP_MotorsCoax.h
+++ b/libraries/AP_Motors/AP_MotorsCoax.h
@@ -42,7 +42,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    uint16_t            get_motor_mask() override;
+    uint32_t            get_motor_mask() override;
 
 protected:
     // output - sends commands to the motors
diff --git a/libraries/AP_Motors/AP_MotorsHeli.h b/libraries/AP_Motors/AP_MotorsHeli.h
index 8b83ff7e2b..2a8f1808bb 100644
--- a/libraries/AP_Motors/AP_MotorsHeli.h
+++ b/libraries/AP_Motors/AP_MotorsHeli.h
@@ -111,7 +111,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    virtual uint16_t get_motor_mask() override = 0;
+    virtual uint32_t get_motor_mask() override = 0;
 
     virtual void set_acro_tail(bool set) {}
 
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp b/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp
index fd66aed249..5310e528e2 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli_Dual.cpp
@@ -473,10 +473,10 @@ float AP_MotorsHeli_Dual::get_swashplate (int8_t swash_num, int8_t swash_axis, f
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsHeli_Dual::get_motor_mask()
+uint32_t AP_MotorsHeli_Dual::get_motor_mask()
 {
     // dual heli uses channels 1,2,3,4,5,6 and 8
-    uint16_t mask = 0;
+    uint32_t mask = 0;
     for (uint8_t i=0; i<AP_MOTORS_HELI_DUAL_NUM_SWASHPLATE_SERVOS; i++) {
         mask |= 1U << (AP_MOTORS_MOT_1+i);
     }
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Dual.h b/libraries/AP_Motors/AP_MotorsHeli_Dual.h
index 9d079f5961..9441674f21 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Dual.h
+++ b/libraries/AP_Motors/AP_MotorsHeli_Dual.h
@@ -78,7 +78,7 @@ public:
     void calculate_armed_scalars() override;
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
-    uint16_t get_motor_mask() override;
+    uint32_t get_motor_mask() override;
 
     // has_flybar - returns true if we have a mechical flybar
     bool has_flybar() const  override { return AP_MOTORS_HELI_NOFLYBAR; }
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp b/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp
index c641994c41..690f602eda 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli_Quad.cpp
@@ -183,9 +183,9 @@ void AP_MotorsHeli_Quad::calculate_roll_pitch_collective_factors()
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsHeli_Quad::get_motor_mask()
+uint32_t AP_MotorsHeli_Quad::get_motor_mask()
 {
-    uint16_t mask = 0;
+    uint32_t mask = 0;
     for (uint8_t i=0; i<AP_MOTORS_HELI_QUAD_NUM_MOTORS; i++) {
         mask |= 1U << (AP_MOTORS_MOT_1+i);
     }
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Quad.h b/libraries/AP_Motors/AP_MotorsHeli_Quad.h
index b6474635b4..e0fc33b200 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Quad.h
+++ b/libraries/AP_Motors/AP_MotorsHeli_Quad.h
@@ -57,7 +57,7 @@ public:
     void calculate_armed_scalars() override;
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
-    uint16_t get_motor_mask() override;
+    uint32_t get_motor_mask() override;
 
     // has_flybar - returns true if we have a mechanical flybar
     bool has_flybar() const  override { return AP_MOTORS_HELI_NOFLYBAR; }
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Single.cpp b/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
index 2d4c7d6f44..a226aa6f02 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
+++ b/libraries/AP_Motors/AP_MotorsHeli_Single.cpp
@@ -355,7 +355,7 @@ void AP_MotorsHeli_Single::calculate_scalars()
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsHeli_Single::get_motor_mask()
+uint32_t AP_MotorsHeli_Single::get_motor_mask()
 {
     // heli uses channels 1,2,3,4 and 8
     // setup fast channels
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Single.h b/libraries/AP_Motors/AP_MotorsHeli_Single.h
index 2f2cbb6719..386033572c 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Single.h
+++ b/libraries/AP_Motors/AP_MotorsHeli_Single.h
@@ -79,7 +79,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    uint16_t get_motor_mask() override;
+    uint32_t get_motor_mask() override;
 
     // ext_gyro_gain - set external gyro gain in range 0 ~ 1000
     void ext_gyro_gain(float gain)  override { if (gain >= 0 && gain <= 1000) { _ext_gyro_gain_std = gain; }}
diff --git a/libraries/AP_Motors/AP_MotorsMatrix.cpp b/libraries/AP_Motors/AP_MotorsMatrix.cpp
index 3b647570ae..8de27cd3a7 100644
--- a/libraries/AP_Motors/AP_MotorsMatrix.cpp
+++ b/libraries/AP_Motors/AP_MotorsMatrix.cpp
@@ -184,15 +184,15 @@ void AP_MotorsMatrix::output_to_motors()
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsMatrix::get_motor_mask()
+uint32_t AP_MotorsMatrix::get_motor_mask()
 {
-    uint16_t motor_mask = 0;
+    uint32_t motor_mask = 0;
     for (uint8_t i = 0; i < AP_MOTORS_MAX_NUM_MOTORS; i++) {
         if (motor_enabled[i]) {
             motor_mask |= 1U << i;
         }
     }
-    uint16_t mask = motor_mask_to_srv_channel_mask(motor_mask);
+    uint32_t mask = motor_mask_to_srv_channel_mask(motor_mask);
 
     // add parent's mask
     mask |= AP_MotorsMulticopter::get_motor_mask();
diff --git a/libraries/AP_Motors/AP_MotorsMatrix.h b/libraries/AP_Motors/AP_MotorsMatrix.h
index e21311ff8b..352b169dd7 100644
--- a/libraries/AP_Motors/AP_MotorsMatrix.h
+++ b/libraries/AP_Motors/AP_MotorsMatrix.h
@@ -60,7 +60,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    uint16_t            get_motor_mask() override;
+    uint32_t            get_motor_mask() override;
 
     // return number of motor that has failed.  Should only be called if get_thrust_boost() returns true
     uint8_t             get_lost_motor() const override { return _motor_lost_index; }
diff --git a/libraries/AP_Motors/AP_MotorsMulticopter.cpp b/libraries/AP_Motors/AP_MotorsMulticopter.cpp
index 2b6aebef15..e2ac056fdd 100644
--- a/libraries/AP_Motors/AP_MotorsMulticopter.cpp
+++ b/libraries/AP_Motors/AP_MotorsMulticopter.cpp
@@ -777,7 +777,7 @@ void AP_MotorsMulticopter::output_motor_mask(float thrust, uint8_t mask, float r
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsMulticopter::get_motor_mask()
+uint32_t AP_MotorsMulticopter::get_motor_mask()
 {
     return SRV_Channels::get_output_channel_mask(SRV_Channel::k_boost_throttle);
 }
diff --git a/libraries/AP_Motors/AP_MotorsMulticopter.h b/libraries/AP_Motors/AP_MotorsMulticopter.h
index 7cbc53dcd9..5c3e583fce 100644
--- a/libraries/AP_Motors/AP_MotorsMulticopter.h
+++ b/libraries/AP_Motors/AP_MotorsMulticopter.h
@@ -68,7 +68,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    virtual uint16_t    get_motor_mask() override;
+    virtual uint32_t    get_motor_mask() override;
 
     // get minimum or maximum pwm value that can be output to motors
     int16_t             get_pwm_output_min() const { return _pwm_min; }
diff --git a/libraries/AP_Motors/AP_MotorsSingle.cpp b/libraries/AP_Motors/AP_MotorsSingle.cpp
index 30801e54d5..c693e53b05 100644
--- a/libraries/AP_Motors/AP_MotorsSingle.cpp
+++ b/libraries/AP_Motors/AP_MotorsSingle.cpp
@@ -103,7 +103,7 @@ void AP_MotorsSingle::output_to_motors()
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsSingle::get_motor_mask()
+uint32_t AP_MotorsSingle::get_motor_mask()
 {
     uint32_t motor_mask =
         1U << AP_MOTORS_MOT_1 |
@@ -113,7 +113,7 @@ uint16_t AP_MotorsSingle::get_motor_mask()
         1U << AP_MOTORS_MOT_5 |
         1U << AP_MOTORS_MOT_6;
 
-    uint16_t mask = motor_mask_to_srv_channel_mask(motor_mask);
+    uint32_t mask = motor_mask_to_srv_channel_mask(motor_mask);
 
     // add parent's mask
     mask |= AP_MotorsMulticopter::get_motor_mask();
diff --git a/libraries/AP_Motors/AP_MotorsSingle.h b/libraries/AP_Motors/AP_MotorsSingle.h
index 2de4866011..bb8f39b2e9 100644
--- a/libraries/AP_Motors/AP_MotorsSingle.h
+++ b/libraries/AP_Motors/AP_MotorsSingle.h
@@ -42,7 +42,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    uint16_t            get_motor_mask() override;
+    uint32_t            get_motor_mask() override;
 
 protected:
     // output - sends commands to the motors
diff --git a/libraries/AP_Motors/AP_MotorsTailsitter.cpp b/libraries/AP_Motors/AP_MotorsTailsitter.cpp
index 7fca4cab2b..c19092d957 100644
--- a/libraries/AP_Motors/AP_MotorsTailsitter.cpp
+++ b/libraries/AP_Motors/AP_MotorsTailsitter.cpp
@@ -113,7 +113,7 @@ void AP_MotorsTailsitter::output_to_motors()
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsTailsitter::get_motor_mask()
+uint32_t AP_MotorsTailsitter::get_motor_mask()
 {
     uint32_t motor_mask = 0;
     uint8_t chan;
diff --git a/libraries/AP_Motors/AP_MotorsTailsitter.h b/libraries/AP_Motors/AP_MotorsTailsitter.h
index 53f1d7a2a2..a456be765b 100644
--- a/libraries/AP_Motors/AP_MotorsTailsitter.h
+++ b/libraries/AP_Motors/AP_MotorsTailsitter.h
@@ -28,7 +28,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    uint16_t get_motor_mask() override;
+    uint32_t get_motor_mask() override;
 
     // Set by tailsitters using diskloading minumum outflow velocity limit
     void set_min_throttle(float val) {_external_min_throttle = val;}
diff --git a/libraries/AP_Motors/AP_MotorsTri.cpp b/libraries/AP_Motors/AP_MotorsTri.cpp
index 1fffd7bec4..bc94fb0f70 100644
--- a/libraries/AP_Motors/AP_MotorsTri.cpp
+++ b/libraries/AP_Motors/AP_MotorsTri.cpp
@@ -127,13 +127,13 @@ void AP_MotorsTri::output_to_motors()
 
 // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
 //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-uint16_t AP_MotorsTri::get_motor_mask()
+uint32_t AP_MotorsTri::get_motor_mask()
 {
     // tri copter uses channels 1,2,4 and 7
-    uint16_t motor_mask = (1U << AP_MOTORS_MOT_1) |
+    uint32_t motor_mask = (1U << AP_MOTORS_MOT_1) |
                           (1U << AP_MOTORS_MOT_2) |
                           (1U << AP_MOTORS_MOT_4);
-    uint16_t mask = motor_mask_to_srv_channel_mask(motor_mask);
+    uint32_t mask = motor_mask_to_srv_channel_mask(motor_mask);
 
     // add parent's mask
     mask |= AP_MotorsMulticopter::get_motor_mask();
diff --git a/libraries/AP_Motors/AP_MotorsTri.h b/libraries/AP_Motors/AP_MotorsTri.h
index 893fb174b8..90b5f25b6c 100644
--- a/libraries/AP_Motors/AP_MotorsTri.h
+++ b/libraries/AP_Motors/AP_MotorsTri.h
@@ -37,7 +37,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    uint16_t            get_motor_mask() override;
+    uint32_t            get_motor_mask() override;
 
     // output a thrust to all motors that match a given motor
     // mask. This is used to control tiltrotor motors in forward
diff --git a/libraries/AP_Motors/AP_Motors_Class.h b/libraries/AP_Motors/AP_Motors_Class.h
index 3b337f86ce..0f0cca18c5 100644
--- a/libraries/AP_Motors/AP_Motors_Class.h
+++ b/libraries/AP_Motors/AP_Motors_Class.h
@@ -221,7 +221,7 @@ public:
 
     // get_motor_mask - returns a bitmask of which outputs are being used for motors (1 means being used)
     //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
-    virtual uint16_t    get_motor_mask() = 0;
+    virtual uint32_t    get_motor_mask() = 0;
 
     // pilot input in the -1 ~ +1 range for roll, pitch and yaw. 0~1 range for throttle
     void                set_radio_passthrough(float roll_input, float pitch_input, float throttle_input, float yaw_input);