Separate system I'd like to touch on. It's part of the start procedure, but requires proper setup, instead of just turning it on:
The main benefit from setting this is getting numbered icons on the Abris display, showing you the position of flight members.
First power the system by setting the 2nd switch on the top to "ON", and make sure "Data link radio equipment" and "Data link VHF radio equipment" radio switches are on. Is all part of normal start-up, so shouldn't have to worry about it.
I'd suggest the first chopper in the selection screen sets his "ID-NO" to 1, second chopper in screen sets to 2, etc. There's only 4 numbers, so chopper 5 sets to 1 again. Grouping is controlled by the radio-frequency of VHF2, which you can set on the left panel.
"DATA" knob controls send/receive mode. Set to "COM" for flightlead (#1) or "WINGMAN" for other flightmembers (#2-4).