cancel_mayday In Ukraine we have minimum separation 5n.m. for arriving traffic. I calculate in such way: if number 1 is 10 n.m. (18,5 километров) from t.d. for #2 and #3 add 6n.m. of track distance, to #4, #5, #6 add aprox 7 n.m. due to ground speed difference.
so if number 5 request track miles: 10+6*2+7*2=36~35 n.m. from t.d.