In short:
The inaugural Batik Air flight from Bali to Canberra is being investigated after the ATSB said it had come in "below minimum altitude".
The ATSB described is as a "serious incident".
What's next?
The bureau said it expects to complete its investigation in the last three months of this year.
The Australian Transport Safety Bureau (ATSB) is investigating the inaugural Batik Air flight into Canberra Airport over what it said was a breach of air safety rules.
The airline was holding an event at the airport on June 14, attended by dignitaries including the Indonesian Ambassador, when its first commercial flight from Bali landed an hour early.
The ATSB said as the Boeing 737-800 approached the airport, about 19 kilometres south of the runway, the crew of the aircraft elected to hold at a designated waypoint in the air.
"During the holding, the aircraft was operated below the minimum holding altitude," an ATSB statement said.
A waypoint is a computer-checked coordinate at each stage of a flight.
The investigator has described it as a "serious incident", and has launched an investigation.
No injuries have been associated with the incident.
The ATSB said it had already interviewed the flight crew and air traffic controller, analysed recorded flight data and air traffic surveillance data and examined pilot and operational records.
"Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties, so that appropriate safety action can be taken," the ATSB said.
The ATSB expects to complete its investigation in the last three months of this year, and its report will be released to the public.
Batik's flights on June 14 marked the first direct flights from Canberra to Bali.
The airline committed to operating three flights a week between the cities, with the ACT Chief Minister saying at the launch he hoped that number might rise to five.