Marking of aeronautical obstacles related to easements T4 (Aeronautical swings) in Eure-et-Loir (28)

Aeronautical easements are intended to ensure the protection of an aerodrome against obstacles, so that aeroplanes can land and take off from it in a safe and regular manner.Some obstacles must be equipped with visual or radio devices designed to report their presence to pilots.The T4 easement is affected by:- all aerodromes open to public air traffic,- restricted-use aerodromes created by the state,- under conditions prescribed by regulation, certain restricted-use aerodromes created by a person other than the State.The base of an easement is the space field (otherwise), the area within which the area is applied. This space field can be defined either in 2D or in 3D in particular in the specific cases of airport clearance easements, easements to protect radio transmission centres.