I have confirmed a tour of the SR Technics Maintenance at the Zurich Airport. There is space for 20 people and the total cost was 400 CHF, so that's 20 CHF per person. If you wish to join you will need to pay upfront to confirm your spot. We are a few colleagues / friends from work but there is space available so I am posting this on Glocals.

The tour will be 2,5 hours and include the SR Technics and Maintenance Area of the Zurich Airport. After arrival, the tour will begin in the main building of SR Technics, where a jet engine and an aeroplane engine are on display. Your tour group will then visit SR Technics workshop, where workers test and assemble countless individual parts. The engines are finally assembled in another part of the workshop. You will be able to watch while this is being done and discover more about how each stage of the procedure is checked. Other highlights of this tour include the visits to Hangars 1, 2 and 3, where large and light aircraft are overhauled. Hangars 2 and 3 are operated by SWISS Technics. The tour reaches its climax in the impressive Hangar 3, which has space for up to four large planes. You will be accompanied by tour guides who have many years of experience at SR Technics and can expertly answer any questions you may have. For more details on the tour see https://www.zurich-airport.com/passengers-and-visitors/shopping-and-attractions/excursions-at-the-airport/sr-technics-swiss-maintenance-tour.

The tour will be held in German but if you ask questions in English for clarification they will respond in English.