What happened
On July 4, 2017, a Boeing 737-800 operating flight LO727 was prepared for departure from Warsaw Chopin Airport (EPWA) to Yerevan (UDYZ). During the takeoff roll on runway 29, the aircraft experienced technical difficulties. Consequently, the crew aborted the takeoff and returned the aircraft to the stand.
Following the aborted takeoff, passengers were disembarked and returned to the terminal, and the aircraft was handed over to maintenance personnel for inspection.
The investigation
The investigation focused on the technical failures identified during the maintenance inspection. The operator's technical department analyzed the fault codes and identified a combination of errors, specifically codes 73-20022, 73-11282, and 79-31142. While the aircraft was technically permitted to fly with these specific codes under existing maintenance documentation (ADD 0014), the simultaneous occurrence of these faults triggered an Engine Control warning light.
Further analysis determined that the fault code 73-20022 indicated an internal fault within the Engine Electronic Control (EEC). As a result, the EEC was replaced to resolve the issue.
Findings
- The primary cause of the incident was a malfunction of the Engine Electronic Control (EEC) for engine number 2.
- The correlation of multiple specific technical faults caused the Engine Control warning light to illuminate during the takeoff roll.
- The event was determined to be an isolated occurrence.