Flight Background
The day before the accident, both propellers of the aircraft were changed at Basel Airport. The pilot returned to his base in Zurich but could not conduct a test of the propellers due to poor weather conditions en route. A test flight was scheduled for September 3.
Test Flight and Incident
After departing from Zurich-Kloten Airport runway 28, the pilot flew east and was cleared to climb to flight level 130 (FL130), the assigned altitude for the test. Ten minutes after takeoff, he informed air traffic control that he would shut down the right engine. The aircraft then lost speed and height, deviating from the prescribed flight path. The pilot successfully restarted the right engine and regained control. Three minutes later, he informed ATC that he would shut down the right engine for a second time. The aircraft entered a right turn, followed by a rapid descent.
Crash
The aircraft crashed in a wooded area and burst into flames. It was destroyed. The pilot, the sole person on board, was killed.
Investigation Findings
Detailed examination of the right engine and its peripherals, along with a simulator reconstruction, identified the probable causes of the accident.