The 2006 fatal crash of the Grob G180A SPn midsize jet prototype was caused by failure of the twinjet’s horizontal stabilizer, according to the final report issued by the German Federal Bureau of Aircraft Accident Investigation (BFU). “The wreckage pattern allowed for only one conclusion: that the horizontal stabilizer had suffered an in-flight breakup due to aerodynamic flutter,” which rendered the aircraft uncontrollable, the report stated. While the cause of the flutter was not determined, the investigators considered a retrofitted elevator mass balance a possible culprit, along with prior damage to the elevator horn. The company’s chief pilot was killed in the crash.
The composite aircraft was not equipped with a flight data recorder or telemetry transfer system, which would have presented investigators with information on its flight profile, system performance and speeds. The only data for the accident was that collected through the local ATC radar traces of the final flight. Likewise, the aircraft was not furnished with a cockpit voice recorder.
