Memory fades, but once upon a time, wasn't there a Rule of the Air that when two aircraft are approaching head - on, each should alter course to the right?
Yes -
if they see each other in sufficient time for an 'alteration of course' alone to effect safe separation. Otherwise a more dynamic manoeuvre may well be required! Some total idiot refused to teach 'emrgency breaks' to the left at a UAS as he was obsessed with this 'alter course to the right' Rule.....
