The Australian Transport Safety Bureau handed down today its long-awaited report into the fiery crash that killed experienced pilot Max Quartermain and four American tourists on their way to a golfing trip on King Island, Tasmania, on February 21 last year.

In its report, the ATSB ruled the Beechcraft B200 Super King plane’s rudder trim, which helped control aircraft movement, was set to full nose-left instead of neutral, causing it to turn — or “yaw” — sharply to the left after takeoff.

The sharp turn hindered the plane’s ability to ascend and about 10 seconds after takeoff, it plunged into the DFO building and erupted into a ball of fire.

The crash instantly killed the pilot and passengers Greg DeHaven, Russell Munsch, John Washburn and Glenn Garland.

Mr Quartermain broadcast a distress call after taking off, repeating “mayday” seven times to air traffic control moments before the crash, but did not explain the emergency.

In its report, the ATSB said had Mr Quartermain followed a pre-flight checklist, he should have noticed the rudder trim was not in neutral position.

The investigation found the pilot had five opportunities in various pre-flight checks to pick up on the error.

“It appears as if the checklist was not followed correctly,” ATSB Chief Commissioner Greg Hood said on Monday.

“There were multiple opportunities in the checklist for the pilot to ensure the rudder trim was in the neutral position prior to take off. For reasons which we were unable to determine, these opportunities were missed.

“This accident and the loss of life of the pilot and four passengers in the view of the ATSB, could have been prevented had a checklist been followed thoroughly prior to takeoff.”

The crash had been described as Victoria’s worst aviation accident in 30 years.

Both engines were working and on-site examinations of the wreckage didn’t identify any faults with the plane that would have contributed to the crash.

The ATSB report said investigations into the crash were hampered due to the plane’s voice recorder not working, due to a tripped “impact switch” that was not reset before the doomed flight.

ATSB investigators also found if the plane hadn’t hit the DFO building, it may have crashed into the busy Tullamarine freeway, possibly resulting in even more casualties on the ground.

The pilot’s widow Cilla Quartermain said in a statement her husband loved being a pilot and always cared about 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, according to the ABC.