System Component Failure Or Malfunction (Powerplant), Mitra Aviasi Perkasa (Perkasa Flying School) (Piper PA28-161 Warrior III PK-PBC) Bandar Udara Tunggul Wulung, Cilacap, KNKT.24.11.24.04

On 11 November 2024, a PA-28-161 Warrior III aircraft, registered as PK-PBC, was operated for mutual training. The flight was planned to depart from Tunggul Wulung Airport (WAHL), Cilacap, to the NANGUN Training Area, which is located on bearing 095º at approximately 14 NM east of Tunggul Wulung, before returning to the airport.

At about 0149 UTC (0849 LT), the aircraft departed from Tunggul Wulung and proceeded toward the NANGUN Training Area via MAOS and ADI Training Area. One of the student pilots acted as Pilot Flying (PF) and the other student pilot acted as Pilot Monitoring (PM).

Upon arriving at NANGUN training area, the aircraft experienced rough engine running, followed by both FADEC A and B warning lights flashing, indicating an engine system malfunction. The PF attempted to reset the FADEC system by pressing the FADEC test button for two seconds; however, the FADEC lights did not extinguish. The PF then activated the FORCE B switch, but neither action was able to restore the engine to normal operation.

The PM declared a MAYDAY call to Tunggul Wulung Air Traffic Control (ATC), reporting the engine failure and that the aircraft was losing altitude. The student pilots decided to land along the Cemara Sewu coastline after determining that the aircraft could not reach the airport.

At about 0231 UTC, the aircraft touched down on the coastline. The pilots did not apply braking during landing but pulled back on the control stick to keep the nose wheel off the surface and to reduce the landing impact. After a landing roll of about 180 meters, the nose wheel sank into soft sand, and the aircraft came to a complete stop.

Following the occurrence, the aircraft engine was examined at the manufacturer’s facility in Germany. A series of controlled engine test runs was performed on a bench stand under various configurations of the FADEC and injectors. The engine run test result indicated an internal malfunction in Injector No. 2.

The occurrence took place during a mutual training flight, highlighting the importance of immediate decision-making and forced landing skills. Although the student pilot responded appropriately by executing a forced landing in a suitable area, the occurrence underscores the need to identify and mitigate potential technical malfunctions before flight.

At the time of issuing this investigation report, KNKT had been informed of several safety actions taken by Perkasa Flying School in response to this occurrence. The flying school revised its Company Maintenance Manual by adding a Maintenance Ground Run-Up Procedure that must be performed by an engineer. The revised manual also included several new procedures, such as the Anomalies Monitoring Procedures and the Maintenance Pre-Flight Procedure.