An ash cloud from a volcano in Chile is disrupting Australian air travel once again, with Qantas Airways and Virgin Australia cancelling domestic flights in and out of Sydney and other key cities, disrupting the travel plans of more than 120,000 passengers. The ash cloud, which is circling the earth for a second time, is expected to reach South Australia by early Wednesday morning after drifting 9,656 kilometres across the Atlantic and Indian oceans. International flights were mostly operating but some flights were being diverted, delayed or cancelled, Australian flag carrier Qantas said on Tuesday. The decision followed the airline, along with Virgin, Jetstar and Tiger, halting services to Sydney, Canberra and Adelaide on Tuesday, stranding tens of thousands of passengers.