CANBERRA, Dec. 8 (Xinhua) -- An Australian small plane that crashed in October and killed both pilots on board broke apart mid-flight before going down, a report has found.
Daniel Burrill, 33, and Darcy McCarter, 23, died immediately when their six-seater Cessna 210 crashed near Gunn Point, east of Northern Territory (NT) capital Darwin, 25 minutes after take-off on October 23.
The journey was a training flight with the two pilots transporting the body of an indigenous man to Elcho Island, 500 km east of the crash site, for a traditional Aboriginal burial.
A preliminary report released by the Australian Transport Safety Bureau (ATSB) said Thursday night that witnesses saw the aircraft descending rapidly with a portion of each wing missing.
Analysis of the wreckage, which spread over more than 800 meters, found that it was consistent with an in-flight break-up with no evidence of fire.
"The main fuselage was found less than one nautical mile from the last recorded radar position and both aircraft wings were located about 700m south-east of that site," the report said.
On the day of the crash, a thunderstorm to the north of Darwin and a strong sea breeze caused a connective cell to develop rapidly between 1:00 p.m. and 1:30 p.m. local time.
The report said one of the pilots requested clearance to divert off-course due to the weather event shortly after they took off at 1:07 p.m.
"At the time of the accident, the pilots were deviating around some significant weather in the area and we believe this would have produced some significant forces at that time," it said.
"Witnesses reported seeing a large cumulus cell form over the Howard Springs area, which they described as a regular occurrence in the build-up season in Darwin."
"Some reported that the cloud went 'very black' at the time of the accident, and that starting about 10 minutes after the accident, it rained heavily for about an hour."
At 1:32 p.m., the plane disappeared from air traffic control radars, an event which controllers assessed as "abnormal."
The radar signal was picked up again 10 seconds later with the plane travelling at an altitude of 5,100 feet and 70 knots, considerably lower than the 10,100 feet and 100 knots it was at just seconds earlier.
Shortly after, the plane again disappeared from the radar and did not re-appear.
"The controllers attempted to make radio contact with the pilots but were unsuccessful," the report said.
A scheduled inspection of the aircraft was completed the day of the crash with no concerns reported.
The full report into the crash is expected to be released by the end of 2018.