What happened
On March 9, 2017, a professional helicopter crew was performing a medical transport mission, tasked with transporting a patient from Trąbki Wielkie to the University Clinical Center in Gdańsk. The flight to the hospital landing site (H010) and the subsequent patient handover proceeded without incident.
After the patient was transferred, the pilot departed from the hospital helipad to return to the HEMS base at EPGD. Approximately two minutes into the flight, at an altitude of roughly 400 ft, the crew observed an "ACTUATION" warning on the warning and caution display, indicating a failure in the yaw control stabilization actuator. Simultaneously, the primary flight display indicated a "Y" message, signaling that manual rudder correction was required. The pilot elected to continue the flight to the base, landing at EPGD without further complications.
The investigation
The incident was recorded in the aircraft's technical log and reported to the LPR technical services. The aircraft was immediately removed from service for inspection. Maintenance personnel from SOT Szczecin examined the system and performed cleaning and wiping of the electrical connector associated with the yaw control stabilization actuator. Following these maintenance actions, the autopilot systems were tested with positive results, and the EC 135 P2+ was returned to operational service.
Findings
- The investigation established that the primary cause of the warning was a contaminated electrical connector on the autopilot yaw control stabilization actuator.