Incident Overview
On 4 June 2021, at 00:55 local time, a Polish Helicopter Emergency Medical Service (HEMS) crew based in Krakow received a task to transport a patient from a hospital in Sandomierz to a hospital in Krakow. The aircraft, a Eurocopter EC-135 P3 with registration SP-HXR, departed at 01:23 LMT.
In-flight Caution and Pilot Response
Twenty-one minutes into the flight, a FIRE EXT caution appeared on the Caution and Advisory Display (CAD) for engine number 1. The pilot, a 44-year-old professional female pilot, shut down engine number 1 in response. After assessing the situation, she returned to the home base at Krakow-Balice (EPKK) and landed safely.
Engine Exceedances
During the return flight, brief exceedances of engine operating limits occurred. The engine manufacturer, Pratt & Whitney Canada, later evaluated these exceedances and determined they were within the engine's operational range.
Maintenance and Return to Service
Following the incident, the helicopter underwent inspection at the SOT Krakow maintenance facility. After consultation with the helicopter manufacturer, the aircraft was cleared for further operation.
Investigation Findings
The investigation determined that the cause of the incident was the accidental switching of the FIRE E/W (Engine/Warning) switch to the TEST position. The pilot, misinterpreting the subsequent caution on the CAD, shut down a fully serviceable engine.
Remedial Actions
The operator implemented a corrective program for the pilot, which included a psychological consultation, detailed analysis of the event with the Head of Helicopter Pilot Training, a briefing and simulator session focusing on emergency scenarios including the actual situation, a standard simulator session, and an Operator Proficiency Check (OPC). The pilot successfully completed all training elements and was reinstated to operational duty.
The Polish State Commission for Aircraft Accident Investigation (PKBWL) accepted these remedial actions and issued no additional safety recommendations.