AN UPDATE from the Australian Transport Safety Bureau revealed three investigations within the Gladstone region are still ongoing.
The 1770 Castaway crash which claimed the life of a female tourist on Middle Island near Agnes Water on January 10 this year isn't expected to be concluded before January 2018.
Initial investigations suggested that engine failure could have been the cause of the crash.
The Australian Transport Safety Bureau has obtained video footage from inside the plane.
The Port Alma anchorage incident that saw two men suffer serious injuries, resulting from a 14-metre fall on January 29 will also conclude at the beginning of the new year.
The Curtis Island helicopter crash on March 17 will be wrapped up this month.
The investigation was expected to be completed mid-July after the Australian Transport Safety Bureau summoned the pilot for questioning following the accident.
The two men involved, a 56-year-old from Margate and a 61-year-old from Scarborough, were found on a nearby beach at Curtis Island in a critical condition.