Solothurn

The single engine airplane departed Grenchen Airfield at 1348LT on a local skydiving flight, carrying 11 skydivers and one pilot. After a climb lasting approximately 14 minutes, the aircraft reached the drop altitude of approximately 3,700 metres above ground level over the departure airfield. The skydivers exited the aircraft in groups through the door on the left side of the aircraft. After the first nine skydivers had left the aircraft, the last two skydivers still on board proceeded to the open door of the aircraft to jump together. They had already jumped together twice earlier that day. The two skydivers remaining in the aircraft took their jump positions at the front and rear door frames, respectively, each facing backward. As a result, the reserve parachute of the skydiver located further toward the rear deployed inadvertently. The skydiver at the front door frame barely noticed the parachute opening. The reserve parachute abruptly pulled the skydiver out of the aircraft, causing the skydiver to collide with the aircraft’s horizontal stabilizer. The horizontal stabilizer was completely severed from the aircraft, causing the aircraft to become uncontrollable and enter a steep descent. The last skydiver remaining in the aircraft then jumped. The airplane crashed in an open field 900 metres from the airfield and was totally destroyed. The pilot was killed.

After passing over the Alps and a layer of stratus over the Plateau, the pilot reached the Willisau VOR where he was cleared to initiate an IFR approach to Grenchen Airport runway 25. He completed a standard turn then followed the 290° radial instead of the published 280° radial. When the DME system indicated 7 NM, the pilot realized he was too far from the normal approach track, disengaged the automatic pilot system and elected to gain altitude. In a flaps down/gear down configuration, the aircraft failed to gain sufficient height and struck, in poor visibility due to thick fog, the wooded slope of Mt Balmfluechöpfli (1,289 metres high) located about 12 km northeast of Grenchen Airport. The aircraft disintegrated on impact and the pilot was killed. The female passenger, slightly injured as she was seating in the seat opposite to the direction of flight, was able to walk away to ask for help.