Werbil
Good idea to have alook at he ICAO migators, Mr Smith only pushes one migator, and this has been proved incorrect on this forum numerous times. Its a problem when dealing with some one who's mind is set in concrete and shows a reluctance to change.
Briefly, the#1 migator is the Captain or PIC. Strange that, but ICAO understand the concept that the command of the flight remains in the cockpit. A proper crew briefing covering the descent and approach, MAP and the visual segment from MDA to the runway. Included in this briefing is the terrain advoidance requirements. ATC have a share of the Captain's responsibility by ensuring that in the approach environment that the aircraft is seperated from both other traffic. Each level assignment below 10,000 is cross checked in the cockpit to ensure compliance with the lowest safe altitudes. In a nutshell, its called situational awareness and the five P's.