Pilot error has been blamed for a 2017 Australian plane crash that killed five people, the Australian Transport Safety Bureau (ATSB) has found.

The plane crashed into the DFO at Essendon Fields adjacent to the airport. Photos: ABC

Pilot Max Quartermain, 63, and four American tourists died when a Beechcraft B200 Super King plane crashed into a Melbourne shopping center shortly after taking off in February 2017.  

In its final report on the crash, released on Monday, the ATSB ruled that the aircraft's rudder trim was in the wrong position at take-off, causing the plane to turn sharply and let in mid-air.

ATSB Commissioner Greg Hood said that Quartermain had five opportunities to pick up on the error before taking off.

"Checklists ensure action items are completed in sequence and without omission," Hood told reporters on Monday.

"In this particular tragic accident there were opportunities in the checklist that existed for the pilot to ensure the rudder trim was set to neutral."

According to the report, Quartermain did not have an appropriate flight check system for the aircraft.

"Although this did not contribute to this accident, it increased the risk of incorrect checklists being used, incorrect application of the aircraft's checklists and checks related to supplemental equipment not being performed," it said.

Mr Quartermain's wife said he would have been doing everything possible to land the plane safely in those final minutes.

Investigators could not establish why the rudder trim was in the full nose-left position but "could not exclude the possibility the rudder trim had been manipulated by unknown persons prior to the flight."

"However the aircraft had been stored in a secure hangar until the previous afternoon," the report said.

"After this, the aircraft was parked outside the hangar within the confines of the airport."

Another contributing factor was that the aircraft was 240 kg over its maximum take-off weight of 5,670 kg.

The investigation revealed that Quartermain made a distress call shortly after taking off, repeating the word "mayday" seven times.

Witnesses of the crash described a "fireball" erupting from the shopping center, which was not open at the time, after the crash.

Mr Hood said the pilot had five opportunities to pick up the error that led to the crash.

The ATSB declared the crash the worst aviation disaster in Victoria in 30 years.

Passengers Greg Reynolds De Haven, Glenn Garland, Russell Munsch and Josh Washburn were bound for King Island, a popular golf tourist destination between Victoria and Tasmania.

It was revealed shortly after the crash that Quartermain was investigated by the ATSB in 2015 for nearly causing a fatal accident but was cleared to continue flying.

Cilia Quartermain, Max's wife and business partner, said in a statement that her husband always cared for his passengers.

"For 40 years he had a successful career in aviation and it is tragic it had to end with his death," she said.

"I know in those terrifying moments of this accident he would have been doing everything in his power to bring the plane safely back to the airport to save his passengers."