We already know HANA High Availability Concept.
I wanted to test this HANA High Availability feature in My Landscape practically and I completed the testing successfully.
I would like to share this Testing experience.
HANA Landscape:
It is 3 Node Scale-Out HANA Landscape.
Node-1: 240f1d253 Master
Node-2: 5d67d765b Slave
Node-3: 89a40ea9a Standby
Now all the 3 nodes are running fine.
Assume The Slave Node - 5d67d765b was getting crashed.
(For Testing Scenario, I manually stopped Slave node - 5d67d765b using HDB STOP operation)
What happened Next ???
Immediately Stand by node - 89a40ea9a took over the Slave node role and
Slave node - 5d67d765b changed as standby.
After few seconds, Stand by node - 5d67d765b back to running status automatically.
I hope this blog might be helpful for you to understand the High Availability feature practically 
Best Regards,
Muthu