On February 22, 2016, an Eurocopter EC-135 P2+ was involved in an aviation accident near Końskie, PL. Investigators recorded the probable cause as: The probable cause of the event was the malfunction of the main rotor RPM sensor. This summary draws on records from the Polish State Commission on Aircraft Accidents Investigation (PKBWL).
On February 22, 2016, the pilot of an EC 135 P2+ helicopter observed the main rotor RPM indicator fluctuating and then stopping. The flight continued to base and landed without incident. Investigation revealed a faulty main rotor RPM sensor.
Incident Summary
On February 22, 2016, during the second minute of flight after departure from Końskie, the pilot of a helicopter model EC 135 P2+ noticed that the needle of the analog triple-pointer tachometer for the main rotor began to fluctuate and then stopped. The pilot decided to continue the flight to the base at EPKA airport. The landing was performed without any consequences.
Investigation and Maintenance
Following the incident, the helicopter was grounded for inspection. A mechanic identified damage to the main rotor RPM sensor. In accordance with the Aircraft Maintenance Manual (AMM 62-41-00), the sensor was replaced with a new one. The proper functioning of the main rotor RPM indication system was verified and found to be satisfactory. Subsequently, the helicopter was released for further operations.
Probable Cause
The probable cause of the incident was determined to be a malfunction of the main rotor RPM sensor.