Incident Overview
On 11 May 2016, the duty crew of a helicopter EC 135 P2+ at the Olsztyn base received a call to Świętajno. During the flight, the helicopter commander observed a 'NO MAP' message on the SMD-68 screen of the EURONAV IV digital map system, indicating a malfunction. Since other systems and equipment were operating correctly, the pilot decided to continue the HEMS mission. The flight and landing proceeded without further issues; the EURONAV IV system remained non-functional throughout the entire flight and only began operating after landing at Świętajno.
Subsequent Malfunction and Recovery
After boarding the patient and restarting the engines, the commander again noticed the 'NO MAP' message. During the flight back to Olsztyn, the EURONAV IV system started with a significant delay but then worked correctly until landing at the hospital helipad. After transferring the patient, the crew flew to the HEMS base in Olsztyn without further incidents. On that leg, the system functioned normally until the helicopter was shut down.
Reporting and Maintenance
The commander reported the system malfunction to the Technical Coordination Center, which decided to apply a Minimum Equipment List (MEL) item 34-28 category D until 9 September 2016. During diagnostic testing, technical personnel identified a fault in the RN6 unit of the EURONAV IV system. On 12 May 2016, the defective RN6 block (P/N 257.011-001, S/N RN6-00689) was removed in accordance with AVM 31-68-01 and replaced with a serviceable RN6 unit (P/N 257.011-001, S/N RN6-00873). After a successful system test per AVM 31-68-01, the MEL was removed and the helicopter was returned to full serviceability. The removed RN6 block was sent to Euro Avionics GmbH in Germany for repair.
Probable Cause
The malfunction of the EURONAV IV system was caused by electronic damage to the main board of the RN6 unit.