What happened
On August 14, 2011, at approximately 11:05 UTC, an HB 23/2400 “Scanliner” motor glider was performing training flights at the Ferlach-Glainach airfield (LOKG) in Austria. The pilot was in the process of completing an induction program for new club members. Following a successful initial landing on runway 22, the aircraft departed on runway 04 and subsequently returned for a second landing on runway 22.
During this second approach, the pilot executed a hard touchdown. While the aircraft initially remained operational and taxied toward the apron, the impact caused significant damage to the nose gear and the left main landing gear. Shortly after exiting the runway, the left main gear collapsed completely, causing the left wing to strike the ground. The pilot and passenger were uninjured and were able to egress the aircraft without assistance.
The investigation
The SUB investigation focused on the sequence of events leading to the landing gear failure and the aircraft's structural integrity. Investigators examined the aircraft's maintenance records, flight documents, and the pilot's experience levels. The investigation also reviewed the aircraft's weight and balance, as well as the meteorological conditions at the time of the accident.
Findings
- The primary cause of the landing gear collapse was a hard landing resulting from an incorrectly calculated flare.
- The pilot's proficiency on the specific aircraft type was low, as they were still undergoing induction training and had not flown the type in the 90 days prior to the accident.
- The pilot's total flight experience was limited, with only 18.5 total hours and approximately 5 hours as the pilot-in-command.
- The aircraft was overloaded by approximately 20 kg, which contributed to the increased stress on the landing gear during the hard touchdown.
- The aircraft's center of gravity remained within the permitted limits during the flight.
- Weather conditions were not a contributing factor to the occurrence.