Accident Details
On 4 May 2016, at approximately 13:25 local time, a glider AC4-ДУ, registration RA-0423A, was performing an approach and landing exercise at Grīvas airfield (ICAO: EVBA) in Kalkūne parish, Daugavpils municipality, Latvia. After the winch cable release, the glider continued to increase its pitch angle, then suddenly rolled to the right. From an estimated height of 15 to 20 meters, it struck the ground nose-down at a shallow angle. The impact caused substantial damage to the glider: the forward fuselage (cockpit) was completely destroyed, and the horizontal and vertical stabilizers were torn from the fuselage. The control cables and linkages for pitch, yaw, and roll showed no visible defects or damage. The winch cable, safety plate, and release mechanism exhibited no signs of failure.
Aircraft Information
The glider was an AC4-ДУ, manufactured in 2015 by OOO "Aviastroitel" in the Russian Federation, with serial number ЕЭBC.03.3134. It was registered in Russia as RA-0423A. The empty weight was approximately 115 kg, and the actual takeoff weight was about 200 kg, within the maximum takeoff weight of 265 kg. The glider was owned by a Russian private individual and had been leased by the pilot for personal use. It was imported into Latvia in disassembled form. No documentation regarding the glider's airworthiness or maintenance history was available.
The winch used for launch was equipped with a Volkswagen 1.8 petrol engine and automatic transmission, with a maximum load limiter set at 160 kg. The winch cable was 1400 m long, 3.8 mm in diameter, with a tensile strength of 700 kg, and the safety plate had a tensile strength of 200 kg.
Pilot Information
The pilot was a 46-year-old Latvian citizen. He held a deltaplane/motodeltaplane pilot certificate (MDP No. 021) issued by the Latvian Civil Aviation Agency on 30 July 2003, valid until 30 July 2005. His medical certificate (Class 2, LVA/MED2-233) was valid until 15 March 2014. No information was available on his total flight hours, flight time on the previous day, or rest period before the accident.
Investigation
The accident was reported by a witness. State Police representatives arrived at the scene but did not notify the Transport Accident and Incident Investigation Bureau (TAIIB) in a timely manner. With police permission, the glider's fuselage was dismantled and removed from the site before investigators arrived, preventing preservation of physical evidence. The next day, TAIIB investigators examined the wreckage, the accident site, and interviewed witnesses. They also reviewed the glider's registration, ownership, and lease agreement.
No flight recorders were installed on the glider. Meteorological conditions at nearby Daugavpils station between 12:00 and 15:00 were suitable for visual flight rules: average temperatures around 19°C, winds light (2.3 m/s with gusts up to 8.1 m/s), and no precipitation. The airfield, Grīvas, is an uncertified airstrip with an 830 m by 90 m grass runway, regularly used by paragliders and skydivers.
A forensic medical examination determined that the pilot died from multiple blunt-force injuries sustained in the crash, consistent with impact against the cockpit structure.