How about:
JAR-OPS 0.485 Performance and compliance with the Rules of the Air
(a) The commander shall satisfy himself (without fear that any one else will disagree with hindsight) that aircraft performance is adequate to enable compliance with the rules of the air and any restrictions applicable to the airspace in which the flight is being conducted; and shall ensure that an aircraft is:
(1) Except when necessary for take-off or landing at an approved landing site, or except where permitted by the appropriate Authority, not flown over the congested areas of cities, towns or settlements or over an open-air assembly of persons if, in the event of an emergency arising, they will cause injury & / or damage to property on the ground.