Upgrade of database (10.2.0.5 to 11.2.0.3) terminating with error ora 3113 - end of communication channel

hi,

My enviroment is ERP 6.0 Ehp0/Oracle 10.2.0.5/AIX 6.1. I'm upgrading the database to 11.2.0.3. using dbua. The steps below are to  be peformed

1. Performing Pre Upgrade
2. Upgrading of Oracle Server
3. Performing post Upgrade
4. Running Custom Scripts
5. Upgrading Time zone

At the end of step 2. the database is shutdown with error "03113 -end of communication channel" hence the remainder of the steps (3 to 5) have not been executed via the GUI (see attached log & screen shots  for clarifications)

Kindly advice on how to completed completed the remainder of the steps for  a succesful database upgrade