What happened
On 6 November 2008, an Express Air Dornier 328-100 (registration PK-TXL) was conducting a scheduled passenger flight from Manado to Fak-Fak via Sorong. The flight, carrying 32 passengers and four crew members, was on short final approach at Torea Airport when the aircraft experienced a sudden and rapid descent.
Data from the flight recorders indicated that the pilot flying adjusted the power levers to a setting that caused propeller disking, leading to an excessive rate of sink. The aircraft touched down heavily approximately 5 meters before the designated touchdown area of runway 10. The left main landing gear struck the ground first, fracturing in two locations, while the right gear touched down 4.5 meters from the runway end. The impact caused the left fuselage to contact the runway surface, sliding for approximately 500 meters before the aircraft came to a stop at the right edge of the runway. While the aircraft sustained significant structural damage to the landing gear and fuselage, all 36 occupants disembarked without injury.
The investigation
The investigation focused on the flight data recorder (DFDR) and cockpit voice recorder (CVR) to understand the sudden changes in propeller RPM and the aircraft's descent profile. Investigators examined the flight crew's performance, noting that the pilot monitoring (the instructor) failed to sufficiently oversee the flight to correct the induced sink rate.
Furthermore, the investigation looked into the airport infrastructure, specifically the Runway End Safety Area (RESA). It was discovered that the area immediately preceding the runway was 30 cm lower than the runway surface itself. The inquiry also reviewed the operator's training records, finding significant gaps in recent Crew Resource Management (CRM) and Approach-and-Landing Accident Reduction (ALAR) training for the crew.
Findings
- The pilot flying reduced power to a level that induced propeller disking, creating an excessive sink rate.
- The pilot monitoring failed to effectively intervene or respond to the rapidly increasing sink rate.
- There was a lack of effective communication and coordination between the crew members, indicating poor Crew Resource Management.
- The flight crew had not undergone formal CRM training for over nine years.
- The airport's runway end safety area did not meet ICAO Annex 14 standards.
- The undershoot area was physically lower than the runway surface, which could exacerbate landing errors.