Singapore Air, Qantas flights sent on merging paths near Perth last Thursday
Australia’s air traffic control lottery has rolled the dice again, sending a Singapore Airlines 777 and a Qantaslink 717 on merging paths north of Perth last Thursday.
Australia’s air traffic control system last Thursday let a Singapore Airlines Boeing 777-300ER with 278 seats fly on a collision course with a Qantaslink Boeing 717 (mostly configured with 115 seats at present) some 303 kilometres north of Perth until urgent action was taken to keep them apart.
Both airliners had been assigned a flight level of 35,000 feet.
The continued occurrence of such loss of safe separation incidents has lead to a special on going CASA audit of AirServices Australia. Recent incidents have included Airservices losing a Virgin Australia 737-800 for most of its flight between Sydney and Brisbane, and lying about the incident afterwards, as well as losing an Etihad Airways A340 for hours while it flew across the inland.
This is what the ATSB says about the investigation it has launched.
Two aircraft, both maintaining flight level 350, were on converging tracks with the same estimate for overhead Morawa NDB, Western Australia. A controller noticed the potential conflict and alerted the sector controllers managing the flights, who acted to resolve the situation. There was a loss of separation assurance.
The brief words from the ATSB are worth careful consideration. It indicates that sector controllers were unaware of the error. One of the critical questions is what lead to these two jets being given the same altitude and crossing courses?
The Virgin Australia and Etihad incidents are among a string of dangerous failures at AirServices Australia that have demonstrated its inability to reliably keep track of and separate aircraft, as well as tell the truth and candidly report its failures to the air safety investigator.
In another incident on 17 October a Qantas Boeing 737-800 near Canberra dropped below the designated safe minimum altitude for its position. The jet was 46 kilometres from the airport, where the flight paths and altitude minimums are set to avoid some of the highest terrain in the country.
This is what the ATSB says about this investigation.
The aircraft descended below the assigned altitude and ATC received a minimum safe altitude warning.
Again the wording, although brief, is laden with meaning, and an unanswered question, which is what caused a Qantas crew to disobey, or overlook, the safe minimum altitude in what is airspace shared with some very clearly identified big hills?