Helicopter Incident at Brynek Landing Site

Incident Overview and Investigation Details On March 19, 2015, an incident involving a Mi-2 Plus helicopter was recorded by the State Commission for Investigation of Aviation Accidents (PKBWL) under case number 369/15. The event occurred at the Brynek landing site (Lądowisko Brynek). The investigation was supervised by Dariusz Frątczak and conducted by the user's commission, concluding on February 2, 2016. No fatalities or injuries were reported, and no safety recommendations were issued by the commission. ## Flight Sequence and Pilot Response Following technical test flights and confirmation of full airworthiness, the helicopter was prepared for a transfer from the EPBC airport to the Brynek landing site, a flight of approximately 2.5 hours. During the final phase of the flight, the pilot observed that the main rotor tachometer needle was positioned at “0.” In response, the pilot increased monitoring of the remaining powerplant control instruments and listened more closely to the sounds of the main transmission and main rotor. The helicopter’s operating parameters, sounds, and controllability raised no concerns for the pilot. Relying on extensive experience with this helicopter type—2,510 hours on the Mi-2 and 4,157 total flight hours—the pilot decided to continue to the destination landing site, which was within visual range. The flight was maintained at the same speed and altitude as before the tachometer malfunction was noticed. The landing was completed without incident. ## Technical Findings and Corrective Actions The main rotor tachometer and its transmitter were removed from the helicopter and sent to the technical department of LPU “Heliseco” for inspection. After a functioning tachometer and sensor were reinstalled, enhanced monitoring of the main rotor indications was recommended during subsequent flights. The fault did not recur. The investigation determined that the lack of main rotor speed indications was caused by a mechanical defect in the main rotor tachometer and a malfunction of its transmitter. ## Preventive Measures The operator implemented several preventive actions: - A safety bulletin describing the incident was issued. - The incident was discussed during periodic pilot training on the Safety Management System (SMS) policy. - During periodic in-flight training on the Mi-2, pilots were trained to identify the correct sounds of the powerplant and other sound sources generated by the helicopter.