Factual Information
On 15 July 2016, at 1344 local time, a glider accident occurred at Namnå, Grue municipality in Hedmark, Norway. The aircraft was an Allstar PZL Glider SZD-55-1, registration LN-GAZ, built in 1990 and operated privately. The pilot, aged 24, held a glider certificate and had logged 161 total flight hours, including 21 hours on type. The flight was part of the national gliding championships, conducting a distance task south of Elverum Airport Starmoen (ENSM).
Weather conditions reported by the pilot were light wind (2 knots from 300°), few clouds, and good visibility, with a temperature of 20°C. The flight was conducted in daylight under visual meteorological conditions (VMC) in uncontrolled Class G airspace. No flight plan was filed.
The pilot reported that the weather was not as favorable as forecast, and after descending, he selected a cornfield for an off-field landing. Water ballast was dumped at 500 meters. On final approach, he noticed the corn was taller than anticipated, approximately 50 cm high. The landing was performed without airbrakes and with a relatively nose-high attitude. During the flare, the tail left a 25-meter-long trail in the corn, and the right wing broke at the root. The pilot was not injured.
Investigation
The Accident Investigation Board (SHT) transported the aircraft to Lillestrøm for examination. Other than the right wing, no significant visible damage was found. The right wing exhibited extensive delamination from the root outward to 70–80 cm, the wing beam was broken in two places, and the beam end piece showed cracks and delamination.
SHT reviewed the glider's maintenance records, which indicated two prior incidents: an accident on 27 June 2001 in Elverum (then on Swiss register) and a repair in January 2004 at a Swedish workshop for damage to the rear fuselage, fin, and stabilizer. Neither repair involved the right wing root area.
SHT requested assistance from Thomas Pyls Flygservice, Sweden, to inspect the wing. The inspection concluded that there were no signs of prior repairs or damage, and the observed delamination and structural failures were consistent with overload from the landing. The bonding with microballoons was noted as less strong than with flocks, but appeared to be per design.
Conclusions
SHT determined that the right wing failed as a result of the loads experienced during the landing in a field of tall corn, and that there were likely no abnormal weaknesses in the wing structure beforehand. Off-field landings are a normal part of gliding operations. The pilot had selected a field that initially appeared suitable, but the tall corn was not apparent until on final approach, making it too late to abort. SHT noted that the risk of surface mismatch cannot be fully eliminated in such situations.