What happened
During a flight operation from an island airstrip, a GA-8 failed to achieve takeoff rotation before reaching the end of the available runway. Prior to the incident, the operator's Chief Pilot had inspected the aerodrome three days earlier and noted the runway was in good condition. However, subsequent rainfall had altered the surface conditions. To increase safety margins, the operator decided to divide the cargo load between two separate aircraft. Based on these calculations, the pilot determined that the remaining runway length was sufficient for the GA-8 to depart safely.
As the aircraft attempted the takeoff, it encountered wet grass and areas of soft ground. These conditions prevented the aircraft from accelerating sufficiently, resulting in the aircraft overrunning the runway.
The investigation
The investigation focused on the state of the aerodrome surface at the time of the occurrence. While the runway had been inspected recently, investigators found that rainfall between the inspection and the flight had created patches of soft earth. These patches were obscured by grass, making them difficult to identify during the takeoff roll.