Originally Posted by iluv2fly
It's been custom and practice on the flights I have taken that this particular announcement from the flight deck began the preparation process. The flight attendant usually gets on the intercom at that time and gives the pax the instructions for landing.
Mine too. In a few cases where they expected turbulence and wanted the FAs seated the last 10 minutes, they let the FAs know and FAs have announced this explicitly to either prepare the passengers early or to ask the passengers to ensure it themselves without FAs checking.
I certainly wouldn't want the FAs to "prepare for landing at their discretion" lest they find it convenient for themselves to do this 10 minutes after take-off.
There is also a one bell and two bell signals some airlines use. Doing it publicly either on the intercom or with the bells allows the pilots to do this quickly without having to wait for an FA or purser to answer a call. So a call would be used only for exceptions that they don't necessarily want the passengers to hear.