Accident Overview
On 8 October 2017 at approximately 13:14 local time, a Robinson R44 helicopter, registration YL-HBH, was involved in an accident in the Gramzda parish of Priekule municipality, near the Gramzda quarry area. The helicopter was operating during the Rally Liepāja event. According to the investigation, the helicopter snagged an overhead power line with its tail rotor, became uncontrollable, and collided with the ground.
Flight Details
The helicopter took off from an area near a rally control post with the pilot and three passengers. After takeoff, it flew at an altitude of about 7-8 meters toward the Gramzda quarry. After approximately 300-350 meters of flight, the pilot observed power lines and sharply increased the pitch angle. However, the helicopter's tail boom and tail rotor struck the upper wire of a 20 kV overhead power line, which was at a height of 9.20 meters. The helicopter then climbed by inertia to about 50 meters, during which the tail section, including the tail rotor, separated from the fuselage. The helicopter became uncontrollable, began rotating about its vertical axis, and subsequently collided with the ground approximately 60 meters from the power line.
Injuries and Damage
The accident resulted in one passenger fatality. The pilot and two passengers sustained injuries of varying severity. The helicopter sustained substantial structural damage, with the tail section found about 50 meters from the main wreckage. The main rotor gearbox shaft was found wrapped with a section of the power line wire. The main rotor blades showed fracture patterns consistent with impact while the engine was running. The flight control cables, rods, and attachments were examined and found without visible defects that would have affected controllability.
Helicopter and Pilot Information
The accident helicopter was a Robinson R44 I, serial number 1616, manufactured in 2006 and registered in Latvia on 7 February 2014. It was owned by SIA "Baltijas Helikopters". Total airframe time was 1402.9 hours; the last 100-hour inspection was performed on 22 August 2017. The pilot, a 53-year-old Latvian citizen, held a private pilot license with helicopter rating (LVA.FCL.000586P) and a valid Class 2 medical certificate. His total flight time was 1725 hours, with 1288 hours on the R44. His last check ride on the R44 was on 4 September 2017.
Power Line Damage
The helicopter struck the upper wire of a 20 kV overhead line. The broken wire fell onto the other two wires, causing a three-phase short circuit, which activated relay protection and disconnected the line.
Meteorological Conditions
No specific meteorological information was provided in the available investigation report excerpt.
Investigation
The Transport Accident and Incident Investigation Bureau of Latvia (TAIIB) conducted the investigation. The report did not state a probable cause.