ATSB investigates engine shut down in remote plane crash

The ATSB report shows that one of the propellers was bent after a crash into Broome mangroves. (Supplied: ATSB)

The Australian Transport Safety Bureau (ATSB) is investigating whether a pilot inadvertently turned a plane's engine off before it crashed in Western Australia's north.

A preliminary report shows that a previously logged defect required both of the plane's engines to be started manually.

An official report will be released once the investigation concludes.

Australia's transport safety watchdog is investigating whether a pilot inadvertently turned a plane's engine off before it crashed in Western Australia's north earlier this year.

The plane, operated by Skippers Aviation, was carrying two pilots and five passengers when it crashed shortly after take-off from Broome airport on March 19, about 2,000 kilometres north of Perth.

The Australian Transport Safety Bureau (ATSB) released its preliminary report into the crash on Tuesday, outlining what it said was "factual information established in the investigation's early evidence gathering phase".

The Australian Transport Safety Bureau has released a preliminary report into a plane crash in Broome in March. (ABC Kimberley: Esse Deves)

While the report does not contain any official findings, the aviation watchdog said a previously logged defect required both of the plane's engines to be started manually.

The report said the flying pilot was "unsure" after take-off whether they had pressed the engine's stop or start buttons.

The control computers responsible for enriching the plane's engines with fuel were not working, according to the report.

"This was logged … meaning the aircraft could still operate, subject to specific conditions," ATSB chief commissioner Angus Mitchell said.

"The aircraft's engines had to be started in manual mode, with the pilots planning to use the left and right START buttons to enrich each engine with fuel."

The Cessna 441 engine start buttons are located next to the stop buttons, on the same panel.

A preliminary report says a mistaken push of the stop button may have caused a plane crash in Broome in March. (Supplied: ATSB)

The plane was being operated by two pilots at the time of the incident — a pilot flying from the left seat, and a training captain on the right.

The ATSB said the pilot flying pressed "what they believed to be the left and right start buttons, without looking at the panel" after take-off.

After noticing a change in engine sound, the training captain asked the pilot flying if they "had pressed the stop buttons".

The damaged steering wheel