Override is now really disabled for multirotors, also I don't think the parameter got ever read by the commander but I might be wrong

apps/commander/commander.c

@@ -1293,6 +1293,8 @@ int commander_thread_main(int argc, char *argv[])
 	uint64_t failsave_ll_start_time = 0;
 
 	bool state_changed = true;
+	bool param_init_forced = true;
+
 
 	while (!thread_should_exit) {
 
@@ -1323,10 +1325,10 @@ int commander_thread_main(int argc, char *argv[])
 			/* handle it */
 			handle_command(stat_pub, &current_status, &cmd);
 		}
-
 		/* update parameters */
 		orb_check(param_changed_sub, &new_data);
-		if (new_data) {
+		if (new_data || param_init_forced) {
+			param_init_forced = false;
 			/* parameters changed */
 			orb_copy(ORB_ID(parameter_update), param_changed_sub, &param_changed);
 
@@ -1335,7 +1337,6 @@ int commander_thread_main(int argc, char *argv[])
 				if (param_get(_param_sys_type, &(current_status.system_type)) != OK) {
 					warnx("failed setting new system type");
 				}
-
 				/* disable manual override for all systems that rely on electronic stabilization */
 				if (current_status.system_type == MAV_TYPE_QUADROTOR ||
 				    current_status.system_type == MAV_TYPE_HEXAROTOR ||

apps/px4io/mixer.c

@@ -84,32 +84,45 @@ mixer_tick(void)
 	int i;
 	bool should_arm;
 
+	/* check that we are receiving fresh data from the FMU */
+	if ((hrt_absolute_time() - system_state.fmu_data_received_time) > FMU_INPUT_DROP_LIMIT_US) {
+		/* too many frames without FMU input, time to go to failsafe */
+		system_state.mixer_manual_override = true;
+		system_state.mixer_fmu_available = false;
+		lib_lowprintf("\nRX timeout\n");
+	}
+
 	/*
 	 * Decide which set of inputs we're using.
 	 */
-	if (!system_state.mixer_manual_override && system_state.mixer_fmu_available) {
-		/* we have recent control data from the FMU */
-		control_count = PX4IO_OUTPUT_CHANNELS;
-		control_values = &system_state.fmu_channel_data[0];
-
-		/* check that we are receiving fresh data from the FMU */
-		if ((hrt_absolute_time() - system_state.fmu_data_received_time) > FMU_INPUT_DROP_LIMIT_US) {
-
-			/* too many frames without FMU input, time to go to failsafe */
-			system_state.mixer_manual_override = true;
-			system_state.mixer_fmu_available = false;
-			lib_lowprintf("\nRX timeout\n");
+	/* this is for planes, where manual override makes sense */
+	if(system_state.manual_override_ok) {
+		/* if everything is ok */
+		if (!system_state.mixer_manual_override && system_state.mixer_fmu_available) {
+			/* we have recent control data from the FMU */
+			control_count = PX4IO_OUTPUT_CHANNELS;
+			control_values = &system_state.fmu_channel_data[0];
+		/* when override is on or the fmu is not available */
+		} else if (system_state.rc_channels > 0) {
+			control_count = system_state.rc_channels;
+			control_values = &system_state.rc_channel_data[0];
+		} else {
+			/* we have no control input (no FMU, no RC) */
+
+			// XXX builtin failsafe would activate here
+			control_count = 0;
 		}
 
-	} else if (system_state.rc_channels > 0 && system_state.manual_override_ok) {
-		/* we have control data from an R/C input */
-		control_count = system_state.rc_channels;
-		control_values = &system_state.rc_channel_data[0];
+	/* this is for multicopters, etc. where manual override does not make sense */
 	} else {
-		/* we have no control input (no FMU, no RC) */
-
-		// XXX builtin failsafe would activate here 
-		control_count = 0;
+		/* if the fmu is available whe are good */
+		if(system_state.mixer_fmu_available) {
+			control_count = PX4IO_OUTPUT_CHANNELS;
+			control_values = &system_state.fmu_channel_data[0];
+		/* we better shut everything off */
+		} else {
+			control_count = 0;
+		}
 	}
 
 	/*