Add RC Link lost - Failsafe Action delay information (#1974)

en/config/safety.md

@@ -36,11 +36,10 @@ This might result in the vehicle being changed to a manual mode so the user can
 
 ## QGroundControl Safety Setup
 
-The *QGroundControl* Safety Setup page is accessed by clicking the *QGroundControl* **Gear** icon (Vehicle Setup - top toolbar) and then **Safety** in the sidebar).
-This includes the most important failsafe settings (battery, RC loss etc.) and the settings for the return actions *Return* and *Land*.
-
-![Safety Setup (QGC)](../../assets/qgc/setup/safety/safety_setup.png)
+The *QGroundControl* Safety Setup page is accessed by clicking the *QGroundControl* icon, **Vehicle Setup**, and then **Safety** in the sidebar).
+This includes the most important failsafe settings (battery, RC loss etc.) and the settings for the triggered actions *Return* and *Land*.
 
+![Safety Setup(QGC)](../../assets/qgc/setup/safety/safety_setup.png)
 
 ### Low Battery Failsafe
 
@@ -65,21 +64,31 @@ Battery Emergency Level | [BAT_EMERGEN_THR](../advanced_config/parameter_referen
 
 ### RC Loss Failsafe
 
-The RC Loss failsafe is triggered if the RC transmitter link is lost in manual modes (by default RC loss does not trigger the failsafe in missions).
+The RC Loss failsafe may be triggered if the RC transmitter link is lost in manual modes (by default RC loss does not trigger the failsafe in missions, hold mode, or offboard mode).
 
 ![Safety - RC Loss (QGC)](../../assets/qgc/setup/safety/safety_rc_loss.png)
 
+Generally you will only want to set the _Failsafe_ action:
+
+- The _RC Lost Timeout_ is the time after data stops updating before the link is considered lost.
+  This must be kept short because the vehicle will continue to fly using the old RC data until the timeout triggers.
+- You may need to modify the [COM_RCL_ACT_T](#COM_RCL_ACT_T) parameter.
+  This is a delay after the link is lost and before the failsafe action is triggered in which the vehicle waits in hold mode for the RC system to reconnect.
+  This might be longer for long-range flights so that intermittent connection loss doesn't immediately invoke the failsafe. 
+  It can be to zero so that the failsafe triggers immediately.
+
 :::note
 PX4 and the receiver may also need to be configured in order to *detect RC loss*: [Radio Setup > RC Loss Detection](../config/radio.md#rc-loss-detection).
 :::
 
-The settings and underlying parameters are shown below.
+Additional (and underlying) parameter settings are shown below.
 
 Setting | Parameter | Description
 --- | --- | ---
-RC Loss Timeout | [COM_RC_LOSS_T](../advanced_config/parameter_reference.md#COM_RC_LOSS_T) | Amount of time after losing the RC connection before the failsafe will trigger.
-Failsafe Action | [NAV_RCL_ACT](../advanced_config/parameter_reference.md#NAV_RCL_ACT) | Disabled, Loiter, Return, Land, Terminate, Lockdown.
-RC Loss Exceptions | [COM_RCL_EXCEPT](../advanced_config/parameter_reference.md#COM_RCL_EXCEPT) | Set the modes in which RC loss is ignored: Mission (default), Hold, Offboard.
+<a id="COM_RC_LOSS_T"></a> RC Loss Timeout | [COM_RC_LOSS_T](../advanced_config/parameter_reference.md#COM_RC_LOSS_T) | Time after RC stops updating supplied data that the RC link is considered lost.
+<a id="COM_RCL_ACT_T"></a>RC Loss Action Timeout | [COM_RCL_ACT_T](../advanced_config/parameter_reference.md#COM_RCL_ACT_T) | Timeout after RC link loss waiting to recover RC before the failsafe action is triggered. In this stage the vehicle is in hold mode.
+<a id="NAV_RCL_ACT"></a>Failsafe Action | [NAV_RCL_ACT](../advanced_config/parameter_reference.md#NAV_RCL_ACT) | Disabled, Loiter, Return, Land, Terminate, Lockdown.
+<a id="COM_RCL_EXCEPT"></a>RC Loss Exceptions | [COM_RCL_EXCEPT](../advanced_config/parameter_reference.md#COM_RCL_EXCEPT) | Set the modes in which RC loss is ignored: Mission (default), Hold, Offboard.
 
 ### Data Link Loss Failsafe