How Australia narrowly avoided two air disasters

Australia’s transport safety inspector says that a failure of flight crews to fully understand take-off conditions nearly led to two major accidents at Melbourne Airport in 2023.

A Malaysia Airlines A330, with 247 people on board, and a Bamboo Airways 787, with 212 people on board, both overran a shortened runway during take off, lifting off only metres above an active worksite.

Each aircraft reportedly took off past the limit of a shortened runway, resulting in “jet blast affecting ... objects and people in the work area”, the Australian Transport Safety Bureau (ATSB) said on Tuesday.

The incidents, which triggered a risk review, were caused by flight crews’ insufficient understanding of take-off conditions, putting the lives of workers, passengers and flight crews in danger.

ATSB chief commissioner Angus Mitchell described the events as “very serious”.

“An aircraft on take-off is one of the most critical stages of flight; anything that can go wrong with an aircraft on take-off has potentially very serious consequences.”

The incidents took place within weeks of each other in September 2023, and a source with knowledge of the events, not authorised to speak publicly, told this masthead that it was the “closest the airport was to real disaster in years”.

Before each incident, the airport’s runway 34, normally 3659 metres long, had been temporarily shortened by about 1568 metres at night for a resurfacing project, which left 2089 metres of runway. In both cases, flight crews used pre-flight take-off calculations that expected a full runway length.

The ATSB said neither the Malaysia Airlines nor Bamboo Airways flight crews had recognised the changed conditions before take-off, despite the warnings being communicated through an update known as a NOTAM (notice to airmen) and broadcast over the radio by the automatic terminal information service.

The Malaysia Airlines flight cleared the work crew by seven metres, while the Bamboo Airways flight passed over by 4.5 metres.

Both times, the jet thrust washed over areas where workers and equipment were present.

When the crew got to the point of take-off, “they knew that they had passed close to lights and workers at the end, but the exact magnitude of that wasn’t apparent to them at the time”, said Mitchell. “And it wasn’t most likely until our interviews with them later that they realised how close.

“Neither flight crew identified that the runway was significantly shortened, despite the relevant NOTAM being provided in their flight briefing packs.”

Commercial planes routinely use what is known as “reduced thrust take-off” that takes advantage of the length of the runway to use less fuel, increasing efficiency and lowering wear on the aircraft. A shorter runway necessitates increased thrust.

The first event involving Malaysia Airlines happened on September 7, 2023. The second occurred on September 18, 2023, with Vietnam’s Bamboo Airways. The runway works ran from 10.30pm at night until 4.30am in the morning.

The Malaysia Airlines crew didn’t confirm they received the ATIS (Automatic Terminal Information Service) notification on the runway, while Bamboo Airways crew had received an earlier version of the update on the runway.

While the two airlines’ office-based flight dispatchers had accounted for the reduced runway length in their calculations, they did not highlight the shortened runway to the flight crews for input into the plane’s flight management computers, said Mitchell.

“Both flight crews assumed the full runway length was available in their performance calculations and their respective take-offs were conducted with less thrust than was needed for the reduced runway.”

The ATSB investigation found that the “risk controls” in place at the time to prevent occurrences like this were “procedural in nature”.

Whilst pilots are responsible for reviewing and understanding all relevant information when preparing for a flight, “these and previous incidents show that this process is susceptible to human error”.

“Considering the potentially catastrophic consequences of a loaded and fully fuelled aircraft impacting a work site on take-off, additional defensive layers are required,” said Mitchell.

As a result of the 2023 incidents, Airservices Australia, in consultation with the Civil Aviation Safety Authority, are proposing changes to air traffic control procedures for how essential information about runway status is communicated.

The ATSB is also urging the International Civil Aviation Organisation to review procedures for air traffic communication to crews on “safety-critical aerodrome conditions”. ICAO has already adopted rule changes for warnings of temporary changes to runway distances.

Immediately after the first event, Melbourne Airport queried Malaysia Airlines, and then published a safety alert to all airlines.

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