The week is divided into two military airtime regimes, called “MIL ON” and “MIL OFF”. Monday to Friday, 7:30 – 12:05 and 13:15 – 17:05 are defined as “MIL ON”. All other times are “MIL OFF”. During “MIL ON”, we are restricted to a ceiling of FL130; in “MIL OFF” this rises to FL150. These heights correspond to 3950m and 4550m ASL at standard QNH. The main significance of this distinction for us is that we are allowed extra height to play with at weekends and in the late afternoon, and may have a window of opportunity to fly through parts of the Sion TMA at lunch-time (as well as after 17.05), as this airspace is usually only activated during “MIL ON” periods.