Incident Overview
On August 11, 2011, a serious incident classified as an AIRPROX occurred approximately 15 NM northeast of Emmen military airfield. The incident involved a Mooney M20J aircraft with radio call sign HB-DHI and a Eurocopter AS532 helicopter with radio call sign T332. The Swiss Accident Investigation Board (SUST) investigated and published final report No. 2157.
Aircraft Information
The Mooney M20J was privately owned. The Eurocopter AS532 was a state aircraft. No further details on the aircraft, such as engine type or modifications, are provided in the initial sections of the report.
Personnel
The report provides information on the pilots of both aircraft and three air traffic controllers from the Emmen control tower and approach control. Details include their licenses, flight experience, and duty times. The pilot of HB-DHI was a private pilot, and the crew of T332 consisted of an examiner and a commander.
Investigation Conduct
The investigation was conducted in accordance with Annex 13 of the Chicago Convention and Swiss law, with the sole objective of preventing future accidents or serious incidents. The report does not assign blame or liability. The German version of the report is the official and binding one.
Report Structure
The report contains sections on factual background, analysis of technical and human factors, conclusions, and safety recommendations. The analysis covers aspects such as air traffic control procedures, crew actions, and operational context. Safety recommendations address the need for safety nets in air traffic control and the lack of equipment on state aircraft.