The Australian Transport Safety Bureau (ATSB) has handed down its first findings from an investigation into a “serious incident” involving Batik Air’s first flight into Canberra earlier this year.
The Indonesian carrier held a special event at the Canberra Airport on Friday, 14 June, to mark the commencement of direct flights between Denpasar, Bali, and Canberra, with several dignitaries in attendance, including the Indonesian ambassador.
The Boeing 737-800 was estimated to arrive at 6 am, about an hour earlier than originally planned due to tailwinds.
However, the preliminary report from the ATSB, released today (4 September), says neither the Canberra Tower nor Canberra Approach air traffic control teams had started for the day, and the pilots decided to handle the approach themselves.
They use the Canberra Airport CTAF (Common Traffic Advisory Frequency), a system where pilots talk to other pilots in the area over the radio to announce their positions.
As the aircraft drew closer to Canberra, it deviated from the route it was expected to use and ended up further south and southwest of the airport.
The report says the controller managing the air space at the time was “unaware of the flight crew’s intentions … but did instruct them to maintain 10,000 feet to remain clear of a restricted area around the Deep Space Communications Complex at Tidbinbilla”.
A short time later, when tracking towards the airport from the south and having descended outside of controlled airspace, the flight crew discovered they were flying too high above their flight path and dropped to 4700 feet.
“But this meant it descended below minimum holding altitude of 5600 feet, and at one point, the aircraft passed 924 feet above terrain,” ATSB Chief Commissioner Angus Mitchell said.
Back at the Canberra Tower, the first controller was about to start the day’s work and noticed the aircraft flying below the minimum altitude.
“The Tower controller made multiple attempts to contact the crew on the Canberra CTAF but did not receive a response,” Mr Mitchell said.
A safety alert was issued to all surrounding aircraft, and it was then controllers finally received a response from the Batik Air crew saying that “they were visual with the runway and continued their approach”.
The flight landed without incident on runway 35.
The ATSB said the rest of the investigation “will consider, among other elements, Batik Air’s procedures, training and route implementation processes, as well as air traffic control procedures and training”.
“A final report with analysis and findings will be released at the conclusion of the investigation, but we note the operator has already pro-actively taken safety actions,” Mr Mitchell concluded.
“These include revising their Canberra Airport briefing documentation, issuing flight crew notices highlighting procedures for operating in non-controlled airspace, and rescheduling flights to Canberra to ensure they arrive during air traffic control operating hours.”