A lack of experience with thunderstorm cells that develop quickly during the Northern Territory's "build-up" season contributed to the fatal crash of a C210 near Darwin according to the Australian Transport Safety Bureau (ATSB).
VH-HWY was on a charter from Darwin to Elcho Island on 23 October 2017 when it crashed 12 nm east of Darwin Airport. The two pilots on board both died in the crash.
The ATSB report released today found that the aircraft broke up in the air after encountering storm cells.
The investigation revealed that the pilot in the left-hand seat was flying in command under supervision (ICUS) from the pilot in the right-hand seat, but neither had any experience flying during the notorious "build-up" to the wet season.
"Shortly after VH-HWY diverted to avoid adverse weather, the aircraft entered an area of strong convective activity and rapidly developing precipitating cells, which resulted in it experiencing severe turbulence and possibly reduced visibility for the pilots," the ATSB report states.
"While flying in these conditions, a combination of airspeed, turbulence and control inputs probably led to excessive loading on the aircraft’s wings, which separated from the fuselage in-flight before it collided with terrain.
"The ATSB found that the pilots had no experience flying in the ‘build-up’ to the wet season in the Darwin area. Although pairing a supervisory pilot with a pilot new to the company was likely to reduce risk in other instances, in this case it did not adequately address the weather-related risks because neither pilot had experience flying in the region during the wet season."
In it's Safety Message, the ATSB conceded that the weather conditions encountered developed so quickly that the pilots would have been unable to make an accurate assessment before departing Darwin, a characteristic of "build-up" weather.
"The ‘build-up’ period to the wet season in Darwin is known for weather conditions hazardous to flying activities," the investigation report states. "Pilots in tropical areas need to recognise and respond to these conditions to avoid the hazards including turbulence, windshear and reduced visibility.
"However, this is more challenging when a pilot has not experienced these conditions, and therefore may not accurately assess the situation or perceive the risks."
The full investigation report is on the ATSB website.