ArduPlane: fix flare rc switch action with flight option bit 10 active

ArduPlane/Attitude.cpp

@@ -190,11 +190,16 @@ float Plane::stabilize_pitch_get_pitch_out(float speed_scaler)
     if (control_mode == &mode_stabilize && channel_pitch->get_control_in() != 0) {
         disable_integrator = true;
     }
+    /* force landing pitch if:
+       - flare switch high
+       - throttle stick at zero thrust
+       - in fixed wing non auto-throttle mode
+    */
     if (!quadplane_in_transition &&
         !control_mode->is_vtol_mode() &&
-        channel_throttle->in_trim_dz() &&
         !control_mode->does_auto_throttle() &&
-        flare_mode == FlareMode::ENABLED_PITCH_TARGET) {
+        flare_mode == FlareMode::ENABLED_PITCH_TARGET &&
+        throttle_at_zero()) {
         demanded_pitch = landing.get_pitch_cd();
     }
 

ArduPlane/Plane.h

@@ -1201,6 +1201,7 @@ private:
     };
 
     FlareMode flare_mode;
+    bool throttle_at_zero(void) const;
 
     // expo handling
     float roll_in_expo(bool use_dz) const;

ArduPlane/radio.cpp

@@ -419,3 +419,15 @@ float Plane::rudder_in_expo(bool use_dz) const
 {
     return channel_expo(channel_rudder, g2.man_expo_roll, use_dz);
 }
+
+bool Plane::throttle_at_zero(void) const
+{
+/* true if throttle stick is at idle position...if throttle trim has been moved
+   to center stick area in conjunction with sprung throttle, cannot use in_trim, must use rc_min
+*/
+    if (((!(g2.flight_options & FlightOptions::CENTER_THROTTLE_TRIM) && channel_throttle->in_trim_dz()) ||
+        (g2.flight_options & FlightOptions::CENTER_THROTTLE_TRIM && channel_throttle->within_min_dz()))) {
+        return true;
+    }
+    return false;
+}

ArduPlane/servos.cpp

@@ -764,23 +764,25 @@ void Plane::servos_twin_engine_mix(void)
 void Plane::force_flare(void)
 {
 #if HAL_QUADPLANE_ENABLED
-    if (quadplane.in_transition()) {
+    if (quadplane.in_transition() && plane.arming.is_armed()) { //allows for ground checking of flare tilts
         return;
     }
     if (control_mode->is_vtol_mode()) {
         return;
     }
-#endif
-    if (!control_mode->does_auto_throttle() && channel_throttle->in_trim_dz() && flare_mode != FlareMode::FLARE_DISABLED) {
-        int32_t tilt = -SERVO_MAX;  //this is tilts up for a normal tiltrotor
-#if HAL_QUADPLANE_ENABLED
+    /* to be active must be:
+       -manual throttle mode
+       -in an enabled flare mode (RC switch active)
+       -at zero thrust: in throttle trim dz except for sprung throttle option where trim is at hover stick
+    */
+    if (!control_mode->does_auto_throttle() && flare_mode != FlareMode::FLARE_DISABLED && throttle_at_zero()) {
+        int32_t tilt = -SERVO_MAX;  //this is tilts up for a normal tiltrotor if at zero thrust throttle stick      
         if (quadplane.tiltrotor.enabled() && (quadplane.tiltrotor.type == Tiltrotor::TILT_TYPE_BICOPTER)) {
             tilt = 0; // this is tilts up for a Bicopter
         }
         if (quadplane.tailsitter.enabled()) {
             tilt = SERVO_MAX; //this is tilts up for a tailsitter
         }
-#endif
         SRV_Channels::set_output_scaled(SRV_Channel::k_motor_tilt, tilt);
         SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorLeft, tilt);
         SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorRight, tilt);
@@ -793,7 +795,8 @@ void Plane::force_flare(void)
             SRV_Channels::set_output_scaled(SRV_Channel::k_throttleLeft, throttle_min);
             SRV_Channels::set_output_scaled(SRV_Channel::k_throttleRight, throttle_min);
         }
-     }
+    }
+#endif
 }
 
 /* Set the flight control servos based on the current calculated values