Tiredness, illness and country and western music are to blame after an Australian solo pilot's 20-minute snooze during a flight to Sydney sparked a minor emergency and a serious air transport investigation.
Michael Cusato was grounded after a sleep on September 1 last year that started shortly after he switched his Cessna 210 to auto-pilot and listened to country and western music on a flight from Port Macquarie to Bankstown airport.
An Australian Transport Safety Bureau report released this week said Cusato failed to respond to numerous calls from air traffic controllers in Brisbane and Sydney.
Twenty minutes later he entered Sydney airspace without clearance, and several thousand feet higher than he should have been, prompting Brisbane Centre air traffic control to issue a safety alert that forced two inbound Sydney flights to fly higher than normal to keep sufficiently clear of the Cessna.
Sydney Approach air traffic control also put an air ambulance flight and a scheduled public transport flight on notice to maintain a visual lookout for the small plane.
The ATSB report noted air traffic controllers had "concerns as to the intentions of the pilot".
Cusato was blissfully unaware until he woke with a shock to realise he was in Sydney airspace with no memory of anything after receiving the clearance to enter Williamtown airspace.
"It freaked me out," Cusato said.
"When I realised where I was I was well into the flight paths of some of the jets."
Cusato, who has 3000 hours flying experience, began a descent to 2500 feet to regain his original flight path, and broadcast his position on a common traffic advisory frequency in case the Cessna posed a risk to other traffic in the area.
During the descent he listened to Brisbane, Williamtown and Sydney frequencies and was relieved there did not appear to have been any issues while he was sleeping.
The incident was immediately investigated by the ATSB, air traffic control and the Civil Aviation Safety Authority.
"I understand why they decided to ground me," Cusato said.
"If they know a guy's fallen asleep then that obviously has to be investigated. It happened to me, and I never thought it would."
Medical tests including sleep apnoea and fatigue tests and a submission have been referred to CASA, which is assessing the material. Cusato said he had had little sleep before he made the flight and was feeling unwell.
"I was quite lucky I did get pinged in controlled airspace because I was being monitored. It was serious, and of course I am very lucky no one else was involved," he said.
Cusato, a country and western music fan, said he could not remember the song he was listening to when he nodded off.
- Sydney Morning Herald