The ATSB report says that the B200 is controllable with full left trim up to 140 KTAS (p46)
The ground speed data shows that the aircraft took off at 11 kt GS and peaked at approx 116 kt before decaying to approx 108 kts at impact (p28)
actual MET data recorded at 1 sec intervals shows the wind at 322 deg magnetic at 4-5 kts for a tailwind component of approx 4 kts
Therefore TAS of the aircraft is (approx) 107 kt (rotation) 112 kt (initial climb) 104 kt (impact).
So... why was the pilot not able to maintain directional control? The ATSB flight simulator exercise shows that at these speeds directional control could be maintained.
Also, why was the aircraft not CLIMBING? If the engines were producing full power, it should have either been diving (increasing airspeed) or climbing. Yet, its airspeed was decaying and it was not climbing.
the ATSB explanation that the cause was sideslip is flawed. The flight simulator testing (p46) was " in order to determine the effects of full left rudder trim on take-off and climb performance" and yet, the ATSB presents no data on take-off or climb performance from the simulator tests and goes on to say " "it was not possible to quantify the effects on ZCR without flight testing or complex engineering modelling. Both of these options was outside the scope of investigation...". This is the very core of the issue that the ATSB conclude, but they say its outside the scope of the investigation????? Really??
The ATSB has labelled the cause as full left rudder trim, yet has not put forward an explanation how it occurred, or how a pilot with 2400 hours on B200 all of a sudden forgot. Nor has the ATSB made any real attempt to prove its theory that the rudder trim led to yaw which led to lack of climb performance. The simulator work that the ATSB commissioned demonstrated that the aircraft could maintain directional control by the pilot at the airspeeds recorded by VH-ZCR. So why didn't a very experienced B200 pilot not push harder on the rudder, keep the aircraft straight and fly away?