Airport slots for General & Business Aviation flights must be cleared to choose one of the handling agents listed in AIP Switzerland LSZH as. Estimated Off-Block Time (EOBT LSZH in UTC);. - Flight number/Call sign. Slot Management co-ordinate ATC slots in co-operation with the. IFR airport slots for flights handled by Cat Air Service, DC Aviation, ExecuJet, Jet Aviation and Privatport can be booked directly via the relevant handling agent.