What happened
On June 29, 1997, a Cessna P 210 carrying a pilot and five passengers was conducting an IFR flight from Graz, Austria, to Mainz-Finthen, Germany. While flying between the Allersberg and Würzburg VOR stations, the aircraft encountered intense turbulence and severe updrafts and downdrafts, indicating the presence of a powerful cumulonimbus cloud.
After notifying Frankfurt Radar, the pilot attempted to navigate around the storm cells. Due to heavy icing, the pilot descended from the planned flight level of FL1SB0. Seeking to avoid the weather, the pilot decided to switch to VFR flight conditions and attempted to land at Bad Neustadt, using GPS data to identify the airfield. However, upon contacting the airfield, the pilot learned that a severe thunderstorm was currently impacting the area, having recently caused significant damage to a hangar roof.
Faced with extreme weather, the pilot opted for an emergency landing in the immediate vicinity. Following an aborted landing attempt in a field due to a microburst and heavy precipitation, the pilot attempted a second landing on the Hochrhönstraße. During this second attempt, shortly after touchdown, the right wing of the Cessna P 210 collided with a large yellow road sign. The impact caused the wing to break off and rotate 90 degrees. The aircraft then underwent an abrupt roll and yaw, sliding 15 meters on its back on a nearby meadow. The accident resulted in two passengers sustaining slight injuries and caused heavy damage to the aircraft and the road sign.
The investigation
The BFU investigation found no technical malfunctions with the aircraft and confirmed that sufficient fuel was on board. The pilot held a German PPL and had recently obtained a US Instrument Rating. While the pilot had been certified to operate high-performance aircraft, the investigation focused on the meteorological conditions and the pilot's decision-making.
Findings
- The primary cause of the accident was the extreme flight conditions during a severe thunderstorm, which forced the pilot to abandon the planned IFR flight and attempt an emergency landing outside of an aerodrome.
- While the pilot had performed proper flight preparations and consulted weather briefings (METAR/TAF), there was doubt as to whether the pilot correctly assessed the potential for the extreme weather intensity based on the available data.
- No significant SIGMETs were active that would have explicitly prompted the pilot to cancel the flight prior to departure.