On 18 September 2017, a departing Airbus A320 was instructed to line up and wait at Yangon but not given takeoff clearance until an ATR72 was less than a minute from touchdown and the prevailing runway traffic separation standard was consequently breached. The Investigation found that the TWR controller had been a temporarily unsupervised trainee who, despite good daylight visibility, had instructed the A320 to line up and wait and then forgotten about it. When the A320 crew, aware of the approaching ATR72, reminded her, she did not know what to do and the trainee APP controller had to intervene.