The captain was the flying pilot for the night landing on runway 01 in IMC, with a right cross wind from 110 degrees at 14 gusting 18 knots, drizzle, and a wet runway. Prior to starting the approach, the flightcrew determined that the landing approach speed (Vref) and the approach speed (Vapp) were 122 and 128 knots, respectively. The airplane flying on autopilot passed the middle marker at 200 feet AGL at 130 knots on the ILS approach. Approximately 3 seconds after the first officer called “runway in sight twelve o’clock,” the captain disconnected the autopilot, while at a radio altitude of 132 feet and on a heading of approximately 18 degrees. Within approximately 11 seconds after the autopilot disconnect, the glideslope and localizer deviation increased. The first officer called “runway over there.” Approximately 5 seconds before touchdown, the airplane rolled right, then left, then right. The airplane crossed the threshold at an altitude of 35 feet and 130 knots and touched down 2,802 feet from the approach end of the 5,495-foot runway (844-foot displaced threshold) at 125 knots. The Saab 340 overran the runway and struck a ditch 175 feet beyond the departure end of the runway. The aircraft was reportedly considered damaged beyond repair and used for spares. PROBABLE CAUSE: “The captain’s failure to follow standard operating procedure for landing on a contaminated ruway in that he touched down long, which combined with his delayed braking resulted in a runway overrun. Contributing factors were the captain’s failure to maintain runway alignment following his disconnect of the autopilot, the gusty crosswind and the wet runway. In addition, the following were contributing factors: (1) the airport operator’s failure to fill in a ditch in the runway safety area, (2) the FAA’s granting of 14 CFR Part 139 approval to the airport when the runway safety area (RSA) did not meet the recommended length for a Part 139 airport, and (3) the FAA’s continued lack of acknowledgement to the airport of the inadequate RSA following their annual airport inspection checks.”