What happened
On 25 December 2016, an ATR 72-600 operated by PT. Wings Abadi Airlines was performing a scheduled passenger flight from Bandung to Semarang. The flight, carrying 68 passengers and four crew members, was operating under night conditions with light rain at the destination.
During the final approach to Ahmad Yani International Airport, the aircraft experienced a series of bounces upon touchdown. After the second bounce, which reached an altitude of approximately 14 feet, the pilot attempted a go-around. However, following a third touchdown, the aircraft's descent rate and impact forces caused the right main landing gear to collapse. The aircraft subsequently came to a stop near taxiway D. While the evacuation was completed successfully without any injuries, the aircraft suffered substantial damage, including a broken propeller tip and fuselage dents.
The investigation
The KNKT investigation focused on the sequence of the landing, the pilot's perception of altitude, and the subsequent emergency procedures. Investigators analyzed flight data recorder (FDR) and cockpit voice recorder (CVR) data, which revealed that the aircraft initially touched down with the nose wheel first.
The investigation also examined the engine shutdown process during the evacuation. It was noted that the engines remained running for several minutes after the aircraft stopped, as the crew intended to maintain cabin lighting for the passengers. The inquiry also looked into the structural integrity of the landing gear, finding no prior defects but noting the extreme vertical acceleration experienced during the impact.
Findings
- The primary cause of the accident was a visual illusion where the pilot perceived the aircraft to be at a higher altitude than its actual position, leading to a late flare-out.
- This late flare resulted in a bounced landing that the crew could not recover from.
- The unrecovered bounce led to an abnormal landing attitude with vertical acceleration reaching 6 g, which caused the failure of the right main landing gear.
- The delay in shutting down the engines during the evacuation was due to the crew's decision to prioritize cabin lighting for passenger safety, though this deviated from the established emergency checklist.
Safety action
Following the preliminary report, the operator implemented several corrective measures. These included issuing notices to pilots to review stabilized approach procedures and adherence to the Operations Manual regarding adverse weather. Additionally, the operator conducted joint emergency evacuation training involving both flight and cabin crews to improve coordination during ground emergencies.