Between 24 and 29 August 2026, calibration flights will be used to assess the navigation systems operated by Skyguide at Zurich Airport. Specifically, this concerns the instrument landing systems (ILS) and the rotating radio beacons (VOR/DME). The calibration flights will take place in the afternoon as well as at night, after the end of normal flight operations, until 2:00 at the latest. Should the calibration flights not be completed between 24 and 29 August due to unforeseen circumstances, the week beginning on 14 September will serve as a reserve period. 

The navigation systems are tested periodically to ensure their accuracy. Approaches to either side of, above, and below the published flight path are required to check the instrument landing systems. Some of the calibration flights will therefore also occur outside the usual approach routes. The reception of the rotating radio beacons must also be tested at greater distances. For this reason, calibration flights will also pass over areas beyond the airport. The signals received by the aircraft from the corresponding navigation systems will be recorded and evaluated. 

A twin-engine Beechcraft King Air 350 propeller aircraft will be used for the calibration flights. The aircraft is equipped with state-of-the-art navigation instruments and a high-precision flight measurement device. Skyguide air traffic control is responsible for the planning and execution of the flights.