Jetstar has cancelled and rescheduled flights to and from Bali because of an ash plume from Indonesia's Mount Merapi volcano.The airline is Australia's most frequent carrier to Bali, with four flights out of Australia each day.
But it has stopped night flights to the island because pilots need to make visual checks on approach to the Denpasar airport.
Tonight's flight from Darwin to Denpasar has been cancelled and a flight from Melbourne to Denpasar was re-routed to Darwin yesterday.
Another flight from Denpasar to Darwin landed in Darwin this afternoon - almost 12 hours later than scheduled.
But passengers accepted the delay.
"We arrived at a civilised hour in Darwin, so all in all it's not such a bad thing," one passenger said.
The airline has rescheduled its Sydney-to-Denpasar service to ensure all flights to Bali land in daylight hours.
"It allows our pilots to have full visual scope of coming into and out of Denpasar International Airport airspace and we're doing that purely as a precautionary measure in line with high safety standards," Jetstar spokesman Simon Westaway said.
Mr Westaway says he is not sure how long Jetstar services will be affected.
"It's a little bit unpredictable in terms of how long this will go on," he said.
"We're getting very accurate advice from the Bureau of Meteorology. We've got a good feel for the situation.
"We've taken a safety-first approach to ensure we can operate safe, efficient operations into and out of Denpasar International Airport and then providing the appropriate response."
Jetstar says it will keep a close eye on the ash plume and is offering passengers refunds or changes to their flights.