Question id 186 - Radio Navigation - ATPL - Airline Transport Pilot license

Beyond 50 to 60 NM because more power can be concentrated in the narrower beam
When approaching coast-lines in polar regions
Beyond 150 NM because the wider beam gives better definition
Beyond 100 NM because insufficient antenna tilt angle is available with the mapping mode

Training tests and timed exam simulations ATPL - Airline Transport Pilot license