What happened
On July 12, 2018, a pilot was conducting a flight from EPPK Kobylnica to EPPO Ławica for the purpose of refueling. Following the refueling process, the pilot received clearance to depart and proceeded with the engine start sequence. During this procedure, the engine gas temperature (MGT) exceeded the safety threshold of 920 degrees Celsius. The pilot immediately aborted the start attempt after the Engine Monitor Unit (EMU) recorded an error. Subsequent analysis of the EMU data confirmed that the temperature had momentarily reached 934 degrees Celsius.
The investigation
The investigation, conducted by the operator's commission, focused on the engine performance data and the sequence of the start attempt. The incident was reported to the Continuing Airworthiness Management Organization (CAMO). Following the discovery of the temperature excursion, the helicopter was grounded. The engine was subsequently removed and sent to an authorized maintenance facility for inspection. After the inspection and reinstallation, the aircraft underwent testing and was returned to service.
Findings
- The primary cause of the incident was an engine gas temperature exceeding the 920 degree Celsius limit during the start sequence.
- A contributing factor was the insufficient time interval between the previous engine shutdown and the subsequent start attempt.