‘Sounded groggy’: Pilot fell asleep for 40 minutes mid-flight after suffering fatigue, mild hypoxia

Disturbing findings into an alarming ghost plane emergency have been revealed, including revelations the pilot fell asleep for 40 minutes.

A Cessna pilot is lucky to be alive after he fell asleep on a flight over Queensland for at least 40 minutes, when air traffic controllers and pilots from nearby aircraft desperately tried to rouse him.

The Australian Transport Safety Bureau revealed the details of the alarming incident on Wednesday in its final report following an investigation.

On a ferry flight from Cairns to Redcliffe in July last year, the pilot encountered unforecast icy conditions and poor visibility due to cloud, and was forced to climb from 10,000 ft to 11,000 ft - a height that requires supplemental oxygen in an unpressurised aircraft.

When the Cessna 208B Grand Caravan was about 53 km from Sunshine Coast Airport, air traffic control attempted to contact the man about his descent into Redcliffe but received no response - for the next 40 minutes.

When the pilot finally woke, he had overshot Redcliffe by about 111 km and flown over the ocean.

Communications were re-established, with air traffic controllers reporting he sounded “groggy” and “not really with it” upon first contact.

A pilot in a Cessna 208B Grand Caravan fell asleep for 40 minutes. This is a generic picture, not the one involved. Picture: iStock

He tried to insist on flying to Redcliffe but they instructed he land at Gold Coast Airport, and his grogginess gradually improved on approach to land.

The plane touched down safely - more than five hours after takeoff.

The pilot reported being confused after waking, not realising how far off course the aircraft had flown, and had no memory of commencing the descent.

Royal Flying Doctor Service pilot Terry Latchman recounted to 7 News, shortly after the mid-flight emergency, how he and colleagues were nearby and had been asked to help try to wake the pilot.

“We were in the right place at the right time,” Mr Latchman told the broadcaster.

The RFDS plane came as close as it could to the Cessna, with the pilots waving its wings and dropping its wheels in a bid to wake the man.

The ATSB found the pilot was likely fatigued due to inadequate sleep the night before and leading up to the incident.

Also, operating at 11,000 ft with only intermittent “sniffs” of supplemental oxygen likely resulted in him suffering mild hypoxia.

“This likely exacerbated the pilot’s existing fatigue and contributed to the pilot falling asleep,” the ATSB said.

The pilot reported he’d had the heater on for about 20 minutes and believed the warmth in the cockpit contributed to him falling asleep.

He was also possibly dehydrated, having drunk minimal water.

“The incident emphasises the importance of pilots monitoring their own health and wellbeing, to ensure that they are well-rested and adequately nourished, especially when conducting single pilot operations,” the ATSB said.