CANBERRA, Australia (CBSDFW.COM/AP) — The pilot of a plane that crashed last year into an Australian shopping mall, killing him and his four passengers from Texas, didn’t properly check the aircraft before takeoff, crash investigators said Monday.

Australian pilot Max Quartermain radioed “Mayday” seven times in 10 seconds but did not explain the emergency before the plane plunged into the Direct Factory Outlet mall in the Melbourne suburb of Essendon on February 21 last year moments after takeoff, the Australian Transport Safety Bureau said.

The investigators’ final report said the rudder trim of the twin-engine Beechcraft King Air B200 was in the full nose-left position instead of a neutral position before takeoff, and the pilot did not detect the mistake.

“The position of the rudder trim resulted in a loss of directional control and had a significant impact on the aircraft’s climb performance in the latter part of the flight,” the report said.

The plane turned to the left after takeoff and reached a maximum height of 160 feet before crashing into the mall and its parking garage. The investigation also found that the plane was overloaded with fuel, but its heavy weight did not contribute to the crash.

“The operator did not have an appropriate flight check system in place,” it added.

Killed were Quartermain, 63, along with passengers Greg Reynolds De Haven, Russell Munsch, Glenn Garland and John Howard Washburn, who all lived in the Austin, Texas, area.

They were heading to King Island, 155 miles south of Melbourne, on a golfing trip.

Officials in Australia called the crash “the worst civil aviation accident that our state has seen for 30 years.”

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)