Airport Obstructions

outline

Airport obstructions Imaginary surfaces Height of objects in approach zone Turning zone Zonal laws

Obstructions are the objects or entities which are present in the path of air craft or on the facilities provided for the aircraft that cause hindrance to the safe and easy movement of the aircraft.

Obstructions are mainly related to type of development and height of development in case of buildings

Classification of obstructions

Obstructions divided into 2 types Imaginary surfaces Objects with actual heights

Assumed surfaces on any airport by which the aircrafts should move above of that particular surface only

Different types of the development in the vertical direction and its height.

Imaginary Surfaces

These imaginary surfaces are basically established surfaces in relation to airport and to each runway above which no obstruction should project.

Size of imaginary surface depends upon The category of each runway Type of approach planned for that

runway

Types of imaginary surfaces

Imaginary surfaces Approach surface Conical surface Horizontal surface Takeoff climb surface Transitional surface

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Approach Surface Provided at the end of landing side of

runway Trapezoidal in shape Diverging away with upgrade Longitudinally centered on the extended

center-line of runway

ILS = Instrumental Landing SystemNon ILS – Non Instrumental Landing System

Take off climb surface Similar to approach surface Provided at the takeoff end of runway Trapezoidal in shape

Imaginary Surfaces

Horizontal Surface Extends from upper edge of transition

surface and ends at lower or inner circular edge of conical surface

The height of outer horizontal surface extends from 150 m (above the ARP elevation) to 9900 m (for airports with length of runway b/w 900 m and 1500 m) or to 15000 m (for airports having runways length more than 1500 m)above elevation of airport reference point.

Imaginary surfaces

The shape of HIS may or may not be circular .

The radius of outer limit measured from the ARP.

Not provided for the airports having runway length < 900 m.

Structures having height above IHS are not permitted.

Imaginary Surfaces

Transition Surface Trapezoidal in shape Extends along the landing strip Slopes upward and outward to the IHS

(Inner Horizontal Surface)

Imaginary Surfaces

Conical Surface Extends upwards and outwards from

inner HS to a point which is at some height above the horizontal surface

Circular in shape

Objects with actual height

any object which is located beyond a distance of 4.5 km from the runway end is considered as an obstruction if its height above 30 meter increases by more than 7.5 meter for each additional 1.5 km distance from the runway.

When we reach 15km from runway end it should not exceed 75m

Any object which projects above the minimum approach flight altitude or whose height exceeds 150 meter above the ground is also to be considered as an obstruction.

Runway Clear zone

Runway Clear zone Provided after runway end starting at

60m from the end within approach area Length determined by approach surface

attaining a height of 30m It is dependant on the rate at which

approach surface is going up

Runway Clear zone

W1 is at the beginning of clear zone that is after moving 60m at the end of strip andW2 is after L distance

Turning Zone

It is used in the case of emergencies for turning of aircraft

any object which is located within a distance of 4.5 km from the ARP is considered as an obstruction if its height exceeds 51 meter above the ground or the established airport elevation whichever is more

any object which is located beyond a distance of 4.5 km from the ARP is considered as an obstruction if its height exceeds 51 meters plus 30 meters for each additional 1.5 km from ARP.

If the value exceeds 150m with in 15km it remains same

Zoning Laws

Height Zoning Given w.r.t. to 4.5km distance from

runway and further w.r.t. every 1.5km upto a distance of 15km from airport

This area should remain with low profile of development

Zoning Laws

Land Use Zoning Governs the type of development which

is taking place at the adjoining areas of airport

These are classified asClosely related like terminal buildings,

parking etc.,Non-Aviation use like commercial,

industrial, residential or recreational

Zoning Laws

Following factors must be considered w.r.t. the zoning laws Zoning laws or legal rules should not hamper the

somebody rights Nature of ordinance or law should have the

qualities like▪ not unreasonable, not arbitrary, not compulsive

Zoning map has to be provided▪ Defines what type of activity can take place at what

distance▪ Helps people to decide their activities▪ It should land use pattern, permissible heights, limits of

zoning laws etc.