Accident Overview
On 5 July 2010 at 13:30 UTC, a VSO-10 glider with registration OM-8509 sustained damage during a landing on an agricultural field in Tužina, Slovakia. The aircraft was operated by SNA gen. M. R. Štefánika and owned by Aeroklub Žilina. The pilot was conducting a competition flight and was not injured.
Flight and Landing Details
During the fifth competition flight, the pilot experienced worsening thermal conditions and decided to land on a pre-selected area, the agricultural field in Tužina. At that time, radio-controlled model aircraft enthusiasts were present on the western side of the field, with parked cars and a group of people, but the landing strip itself was clear. The pilot chose to land into the wind, heading south, to avoid interfering with the modelers.
The glider touched down just beyond the northern threshold of the field. However, the wind, which had been from the southwest, shifted to a northeasterly direction. This change, together with the slope of the field, caused the glider's landing rollout to extend beyond the southern threshold. Beyond the threshold was a meadow with a terrain wave.
During the braking phase, with the tail skid raised, the glider ran down the terrain wave, resulting in damage to the aircraft.
Damage to the Aircraft
After the accident, the glider remained in one piece but sustained damage including a split in the bottom fuselage joint approximately 20–30 cm in length and detachment of the cockpit floor from the side laminate. The glider lost its airworthiness certification and was required to undergo inspection and repair at an approved maintenance organization.
Investigative Analysis
The investigation noted that landing gliders in unfamiliar terrain demands careful inspection of the chosen area. The pilot's selection must account not only for wind orientation but also surface conditions, slope, bearing capacity, and vegetation. This accident illustrated many of these factors. According to the pilot's statement, the change in wind direction and the field's slope caused the extended rollout and subsequent damage.
Cause
The probable cause of the accident was determined to be the pilot's failure to master piloting technique during landing.
Safety Recommendations
The final report issued no safety recommendations.