Conditions and circumstances for Lifeflight to be called is determined by the Public Safety organizations of the county. For landing site selection a helicopter requires a minimum area 60 by 60 feet, free of wires and obstructions directly overhead and not more than an eight degree slope. Avoid dusty areas. Hosing down an area helps. Site should be marked; usual markings are an emergency vehicle with flashing lights, smoke bomb, flares or car headlights criss-crossing each other at right angles.