Transport authorities still do not know why a small plane crashed into a Melbourne shopping centre last month after discovering that its black box failed to record the fatal flight.
The last recorded audio on the cockpit voice recorder was from a previous flight on 3 January, the Australian Transport Safety Bureau said in a preliminary report into its investigation, leaving investigators with no additional information about what may have happened to cause the eight-seater plane to crash minutes after takeoff, killing the pilot and four passengers.
The B200 King Air plane took off from Essendon airport at 8.59am on 21 February and immediately veered left, losing altitude and crashing into the roof of the Essendon Direct Factory Outlet shopping centre before coming to rest in the car park.
It was carrying the US tourists Greg De Haven, Russell Munsch, Glenn Garland and Josh Washburn, who were heading to Tasmania for a golfing trip. The pilot, 63-year-old Max Quartermain, had 38 years’ experience and had been flying private charter flights for 25 years.
In a statement released alongside the the ATSB’s preliminary report on Wednesday, its chief commissioner, Greg Hood, said considerable damage caused by both the impact and the resulting fire had made the investigation difficult.
“The extensive damage caused by the collision and post-impact fire has meant investigators are yet to determine a clear picture of the causal factors behind the accident and loss of life,” he said.
“I offer my deepest sympathies to the families and loved ones of those on board the aircraft. Every effort is being made to determine the cause of this tragic accident.”
The cockpit voice recorder was burned but its solid-state hard drive was undamaged. Technicians at the ATSB’s Canberra headquarters were able to download the drive and play it back but have so far not been able to figure out why it was not recording. “The ATSB is examining the reasons for this,” Hood said.
Audio from the Essendon airport control tower simply records Quartermain saying “mayday” seven times. “No additional information regarding the nature of the emergency was broadcast,” the ATSB report said.
The report said the plane was observed to “yaw” or tilt left after becoming airborne and perform a shallow climbing left turn, reaching a maximum height of 160 feet (nearly 50 metres) before crashing.
“On-site examination of the wreckage did not identify any pre-existing faults with the aircraft that could have contributed to the accident,” the report said.
There was also no evidence that either of the engines had failed, after they were disassembled and inspected by ATSB officers. Earlier reports suggested the crash had been caused by “catastrophic engine failure”.
“That examination found that the cores of both engines were rotating and that there was no evidence of pre-impact failure of either engine’s internal components,” the report said. “However, a number of engine components were retained for further examination and testing.”
The final report into the investigation could take up to a year.
