The Australian Transport Safety Bureau has detailed early evidence gathered in its ongoing investigation into two incidents where widebody airliners took off beyond the end of a temporarily shortened runway at Melbourne Airport in September, 11 days apart.
In both instances, the northern end of Melbourne’s north-south runway (16/34) was closed for runway works. As a result, aircraft taking off on the runway had 2,089 metres available for take-off, compared to the normal 3,657 metres.
“This shortened runway state was detailed in the airport’s notice to airmen (NOTAM) and broadcast over radio via the automatic terminal information service (ATIS), but in both incidents, the flight crews were not aware of the shortened runway and selected the normal full length for the aircraft’s performance calculations,” Chief Commissioner Angus Mitchell explained.
In both incidents, each aircraft’s flight computer responded to the full-length runway selection by providing settings for a reduced-thrust take-off – standard practice to reduce engine wear when a full-powered take-off is not necessary.
“Both aircraft subsequently passed the end of the shortened runway 34 during their take-off rolls, and lifted off within the 450-metre buffer zone between the runway’s temporary end and the edge of the worksite,” Mr Mitchell said.
In the first occurrence, flight data shows a Malaysia Airlines Airbus A330-300 lifted off the runway approximately 170 metres before the worksite, passing over the nearest works boundary at about 21 feet in height above the runway.
In the second occurrence, a Bamboo Airways Boeing 787-9 lifted off in a similar location, and was estimated to have passed over the nearest works boundary at approximately 10-16 feet.
As a result of these occurrences, Melbourne Airport cancelled the remaining planned runway works requiring a displaced threshold/shortened runway.
“The ATSB’s preliminary report has been prepared to provide timely information to the industry and public, and includes a summary of the evidence gathered so far, which comes from NOTAM and ATIS information, CCTV footage, air traffic control audio, interviews with flight crews, recorded flight data, and other sources,” Mr Mitchell said.
“As the investigation progresses, we will continue to further review and analyse this evidence, as well as runway works planning and risk assessments, and mechanisms for the communication of safety-critical aeronautical information to air crews.”
A final report will be released at the conclusion of the investigation.
“Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties so appropriate and timely safety action can be taken,” Mr Mitchell concluded.
You can find here the preliminary report: Runway excursions on take-off involving Airbus A330-323 9M-MTL and Boeing 787-9 VN-A819 at Melbourne Airport, Victoria, on 7 and 18 September 2023
