If I remember correctly in the USA they will clear IFR aircraft in E to depart in non radar airspace where the first aircraft turns 30 degrees left from runway heading and the next aircraft 30 degrees right . Not initially an ICAO IFR standard but they clearly can’t hit. That is the type of standard we have to copy if we are going to get the NAS to work efficiently without all the delays that are quoted by the ignorant on this site.