What happened
During an arrival at Kompong Som Airport, an aircraft experienced a runway excursion following its landing on runway 21. Upon making contact with the runway surface, the flight crew was unable to decelerate the plane within the available runway length. The aircraft subsequently exited the paved surface and came to a stop inside a nearby drainage ditch.
While the incident resulted in the aircraft being damaged beyond repair, there were no injuries reported among the two pilots on board.
Findings
Investigation into the mechanical state of the aircraft revealed significant discrepancies in system pressures prior to or during the landing sequence. Specifically, the hydraulic system was operating at a pressure of 700 psi, which fell below the required operational range of 800-1050 psi. Additionally, the braking system pressure was recorded at 600 psi, representing the lower limit of the expected 600-800 psi range. The insufficient hydraulic and braking pressure contributed to the inability to halt the aircraft before it left the runway.