Made failsafe more intuitive. Default (0) maps to whatever channel is throttle. If a non-zero value is entered, a direct channel map is used so use

src/modules/sensors/sensor_params.c

@@ -538,28 +538,13 @@ PARAM_DEFINE_INT32(RC_MAP_PITCH, 2);
 /**
  * Failsafe channel mapping.
  *
- * The RC mapping index indicates which rc function
- * should be used for detecting the failsafe condition
+ * The RC mapping index indicates which channel is used for failsafe
+ * If 0, whichever channel is mapped to throttle is used
+ * otherwise the value indicates the specific rc channel to use
  *
  * @min 0
- * @max 14
+ * @max 18
  *
- * mapping (from rc_channels.h)
- * 	THROTTLE = 0,
-	ROLL     = 1,
-	PITCH    = 2,
-	YAW      = 3,
-	MODE = 4,
-	RETURN = 5,
-	ASSISTED = 6,
-	MISSION = 7,
-	OFFBOARD_MODE = 8,
-	FLAPS   = 9,
-	AUX_1   = 10,
-	AUX_2   = 11,
-	AUX_3   = 12,
-	AUX_4   = 13,
-	AUX_5   = 14,
  *
  */
 PARAM_DEFINE_INT32(RC_MAP_FAILSAFE, 0);  //Default to throttle function