What happened
On 20 March 2018, a Super Decathlon 8KCAB, registration PK-RTZ, was performing a solo aerobatic flight exercise at Tunggul Wulung Airport in Cilacap, Central Java. The flight was part of a rehearsal for an upcoming student pilot graduation ceremony. The aircraft had previously departed in formation with three Cessna 172s, which landed and waited while the PK-RTZ proceeded with its solo maneuvers.
Video evidence of the flight shows the pilot executing a series of maneuvers, including loops, Cuban eights, and multiple Split-S maneuvers. During the final, unidentified maneuver, the aircraft climbed and entered a left roll that transitioned into an inverted position. As the pilot attempted to level the aircraft, the plane descended across runway 31 at a low altitude. The aircraft struck the apron, bounced, and careened into the Perkasa Flying School hangar.
The investigation
The KNKT investigation analyzed amateur video footage, airport CCTV, and wreckage patterns. The investigators examined the aircraft's flight path, the sequence of aerobatic maneuvers, and the physical damage to the aircraft and surrounding structures. The investigation also reviewed the flight preparation and the specific parameters of the aerobatic maneuvers being performed.
Findings
- The pilot initiated a roll at an altitude and timing that did not align with established safety guidelines.
- This premature roll resulted in the aircraft being at an insufficient altitude to safely recover.
- The aircraft's low altitude during the recovery phase caused it to strike the apron and bounce toward the hangar.
- The accident resulted in one fatality (the pilot) and substantial damage to the PK-RTZ and six other aircraft located on the apron and within the hangar.
Safety action
- The KNKT issued a recommendation to the aircraft operator to address the identified safety issues regarding aerobatic flight execution.