Map of the airport.

a) transects used for the “entire airport” assessment. The stimuli could be seen at some places within Z1 and Z6 from a distance (> 400 m), red squares: places were observers made recordings; b) the screen area seen from the fixed observation post (within the oblique red lines), the section of the runway were the risk of collisions is the greatest lies between alpha and bravo, blue rectangle: screens.