In all EU Member states, the Standardised European Rules of the Air apply: these set out a minimum altitude of 150 m (500 ft) above any obstacle within a radius of 150 m (500 ft), except with permission, or when taking off or landing. If an aircraft is flying over a congested area (town, settlement, etc.) it must fly high enough so that in the case of an engine failure, it is able to land clear safely "AND" it must not fly less than 300 m (1000 ft) above the highest fixed object within 600 m of the aircraft.