On 13 January 2005, the second of the two development aircraft crashed in Buochs, Switzerland, while conducting an aerobatic training flight; the accident resulted in the death of the pilot as well as injuring another person on the ground. In response to the accident, the other PC-21 was grounded for several weeks until Swiss authorities had established that there was no sign of technical malfunction. In August 2006, it was announced that crash investigators had concluded that pilot error had been a primary cause. In late August 2005, the first pre-series production PC-21 performed its maiden flight.