The merits of having manned control towers at the country’s mainline airports is illustrated in this preliminary report by the Australian Transport Safety Bureau into an incident near Melbourne on 4 November last year.
The Thai International Boeing 777 was carrying 294 passengers and crew when the control tower spotted its lights in the gap between low clouds and hills about 12 kilometres north of Tullamarine.
The duty controller radioed the crew to “check your altitude immediately”.
This diagram shows the instrument landing approach profile the crew should have flown (in blue) and the actual route they did fly (in red) with a purple patch indicating the moment the jet caught the tower’s attention.
The incident’s preliminary investigation has now moved from the factual phase to a review of how the crew had been trained.
It shows that they were hunting for a visual fix on the runway, during which the ground proximity warning system in the airliner went off twice shortly before they were spotted by the tower.
At that point the underbelly of the jet was only 150 metres above the tranquil rural gardens of the area and doing about 300 kph, or as close to the ground as they should have been just before crossing the airport boundary seconds before touchdown.