Sequence of Events
On April 21, 2002, at 23:40 UTC (08:40 LT), an Antonov AN-72, registration ES-NOP, operated by PT Trigana Air Services as a cargo charter flight, departed Sentani Airport, Jayapura, bound for Wamena. The flight crew consisted of three cockpit crew members and a loadmaster. This was the third of eight planned flights between Sentani and Wamena that day. Weather along the route was clear. The aircraft cruised at 16,000 feet. After waypoint 'Maleo', it overflew the 'north-gap' and began descent while passing the 'pass valley'. Three other aircraft were in the area: a Fokker F27 PK-YPQ and two Antonov A26 aircraft (ER-AFQ and ER-AFE). Over 'Yiwika', 7 nautical miles from Wamena, descending through 12,000 feet at 330 km/h, ES-NOP overtook ER-AFE. The crew had the runway in sight. The pilot-in-command, acting as pilot flying, performed an 'S' approach pattern during final. At 24:15 UTC (09:15 LT), on final at 100 meters altitude, the aircraft was aligned with runway 15 centerline. It touched down within the touchdown zone, bounced twice, with the second bounce more severe. The aircraft rolled down the runway, with the crew noticing an unusual nose-down attitude. The pilot applied reverse power and brakes, using rudder control.
Smoke and Evacuation
During the roll, the loadmaster, seated behind the PIC, observed black smoke rising from the forward floor of the cargo compartment. The crew reported the smoke irritated their eyes. The aircraft decelerated with smoke emanating from the forward cargo area. After stopping, the loadmaster opened the aircraft door and retrieved a fire extinguisher. The PIC shut down the engines, opened the left cockpit window, and assisted the loadmaster. The first officer completed shutdown procedures while vision was obscured by smoke. The flight engineer unsuccessfully attempted to open the overhead emergency exit. Both the first officer and flight engineer evacuated through the left cockpit window, while the PIC and loadmaster exited through the door.
Firefighting Response
ATC, observing the occurrence and noting the unserviceable crash bell, notified the Deputy Chief of the airport and alerted the fire brigade. Firefighters failed to start the fire truck initially. After recharging the battery for about 10 minutes, a second attempt also failed. The battery was recharged again while personnel ran to the aircraft's final position carrying portable extinguishers. After another 10 minutes, the fire truck started and proceeded to the site. After refilling fire-extinguishing agent, the fire was extinguished approximately 30 minutes later.
Damage and Runway Closure
The aircraft was seriously damaged, with the front side completely burnt out. A hole was cut from behind the cockpit roof to approximately the middle of the cabin roof. The cargo was totally consumed by fire. No injuries occurred. Following the accident, Wamena airport was closed to Fokker 27 or larger aircraft but remained open for DHC-6 (Twin Otter) or smaller. The NTSC investigation team arrived on April 21. On April 22 at 02:00 PM local time, clearance was given to remove the aircraft from the runway. At 05:00 PM, airport personnel began removal using a large backhoe. By 08:30 PM, ES-NOP was cleared from the runway. On April 23, airport activities returned to normal.
Probable Cause
The following findings were identified by the investigation: The crew performed a visual approach to Wamena at an airspeed exceeding the provisions of the AN-72 manual. The crew failed to properly estimate the distance to start the final turn, preventing them from decreasing speed and extending flaps to landing configuration. The high rate of descent and flap configuration activated the GPWS warning. The landing speed exceeded the prescribed value, and the aircraft had a slight drift angle at first touchdown. After the first touchdown, the aircraft bounced three times, which, combined with high loading, led to nose gear failure. The fire resulted from heat due to friction as components skidded on the runway and hydraulic fluid leaked from damaged systems. No system malfunctions or maintenance misconduct contributed. The fire brigade at Wamena was not in a ready condition, leading to delayed fire suppression; equipment was non-serviceable, and personnel lacked training. Additionally, a blank radio transmission area existed at the 'north-gap', and the lack of a type certificate for the AN-72 slowed the investigation.