What happened
On October 23, 2024, a Diamond HK 36 TC Super Dimona motor glider departed from the Bad Marienberg glider airfield for a VFR flight toward Leutkirch-Unterzeil. The aircraft was carrying the pilot and one passenger. During the flight, which proceeded through Class E and G airspace, the aircraft traveled past Wiesbaden, Frankfurt, and Heidelberg, eventually moving toward Tübingen.
As the aircraft approached the area near Lichtenstein, the pilot encountered increasing cloud density. To avoid becoming trapped above the cloud layer, the pilot decided to descend below the clouds. While attempting to navigate through a valley to reach an alternate landing site at Übersberg, the aircraft became boxed in by clouds. In an attempt to climb out of the valley, the pilot applied full power and initiated a climbing turn. During this maneuver, the nose gear struck the treetops, leading to a crash in a forested area.
The investigation
The BFU investigation examined flight data from the aircraft's FLARM system and analyzed meteorological conditions. The investigation established that while the flight began under VFR conditions, the weather in the area was characterized by low cloud bases and reduced visibility. The investigators also reviewed the pilot's use of the ForeFlight application for navigation and confirmed that no technical malfunctions were present in the aircraft prior to the impact.
Findings
- The pilot attempted to maintain VFR flight while flying through deteriorating weather conditions.
- The aircraft was flying in a valley where the cloud ceiling was low, and the pilot became trapped by clouds while attempting to maneuver.
- The primary cause of the accident was the collision with rising terrain during a climbing turn initiated to escape the cloud layer.
- The pilot had not consulted a flight weather service or logged into a briefing portal on the day of the accident.
- The pilot and passenger both sustained serious injuries, including rib fractures and a spinal fracture.