A Dornier 328-110 passenger plane, registered PK-TXL and operated by Express Air, sustained substantial damage during a hard landing at Fak Fak Airport (FKQ), Indonesia. Express Air flight 9000 left Sorong (SOQ) at 09:58 local time on a domestic flight to Fak-Fak (FKQ). The Pilot in Command was the flight instructor and was also pilot monitoring during the flight. The First Officer was the handling pilot from the left seat. He was undergoing command training on the aircraft type. Another First Officer (FO2) was located in the observer seat in the cockpit. The aircraft descended suddenly and rapidly when it was on short final approach. About 65 seconds before ground impact, the RPM of both propellers commenced to decrease to approximately 70%. Propeller RPM then suddenly reduced, followed by an immediate and rapid increase of propeller RPM to 111% left and 97% right, then just as sudden and rapid, the left propeller RPM reduced to 77% and the right to 80%. It is likely that an attempted corrective action was made by the PIC. However, it was too late to prevent the aircraft from touching down before the end of the runway. The aircraft touched down heavily approximately 5 meters before the touch-down area of runway 10. It struck the raised lip of the runway causing the left main gear to collapse. It stopped on the runway, approximately 500 meters from the touch-down area. The investigators found that the aircraft operator did have a robust crew resource management (CRM) implementation training program and did not have a Line Operations Safety Audit (LOSA) program. Also, there was no evidence that any of the pilots had completed any form of CRM training for more than 9 years. And other than the handling pilot, there was no evidence that the pilots had completed ALAR/CFIT training. CAUSES: The Digital Flight Data Recorder data showed evidence that the aircraft descended suddenly and rapidly when it was on short final approach before the aircraft was above the touch-down area. Propeller RPM was reduced suddenly and rapidly to 70% less than 10 seconds before ground contact. Given that the propellers are constant speed units, the sudden and rapid changes could not be explained other than the probability that a crew member had made the control inputs. The PIC (pilot monitoring/flight instructor) did not monitor the operation of the aircraft sufficiently to ensure timely and effective response to the pilot induced excessive sink rate. Other Factors: The airport did not meet the ICAO Annex 14 Standard with respect to the requirement to have runway end safety areas.