Hy LEM,nice to hear from you
Actually,Boeing says in the FCTM (1.42 oct31/2003) that a/t use is recommended during takeoff and climb in either automatic or manual flight.During all other phases of flight,a/t use is recommended ONLY when the autopilot is engaged.
This is for a good reason. Although the ARM mode provides the minimum speed protection,usage of a/t arm mode in manual flight can have its down sides during landing,as batty said.
We don't use it ,but we had some pilots doing contracts for short periods at companies that insist on using the arm feature.
The a/t kicked in in a few instances,very close to the ground,almost during flare,not very funny. It can cause a tailstrike very easilly.
My guess,better full manual or full auto.Mr B knows why it doesn't "recommends" mixage.The system was not designed for that.Not like the bus has.
Brgds
Alex