The document discusses airport obstructions and imaginary surfaces. It defines obstructions as objects that interfere with aircraft movement and lists different types of imaginary surfaces like approach, takeoff, horizontal, and conical surfaces established around airports and runways. These surfaces define the heights and areas where no obstructions are allowed based on factors like runway length and type of landings. The document also discusses zoning laws that govern land use and height of developments near airports to ensure safety of aircraft operations.
2. Airport obstructions
Imaginary surfaces
Height of objects in approach zone
Turning zone
Zonal laws
3. 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
4. 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.
5. 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
9. 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
10.
11.
12. ILS = Instrumental Landing System
Non ILS – Non Instrumental Landing System
13.
14.
15. Take off climb surface
Similar to approach surface
Provided at the takeoff end of runway
Trapezoidal in shape
16.
17. 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.
18. 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.
19. Transition Surface
Trapezoidal in shape
Extends along the landing strip
Slopes upward and outward to the IHS (Inner
Horizontal Surface)
20.
21. Conical Surface
Extends upwards and outwards from inner HS to
a point which is at some height above the
horizontal surface
Circular in shape
22.
23.
24. 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
25. 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.
26.
27. 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
28. W1 is at the beginning of clear zone that is after moving 60m at the end of strip and
W2 is after L distance
29.
30. 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
31. 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
32. 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
33. Land Use Zoning
Governs the type of development which is taking
place at the adjoining areas of airport
These are classified as
Closely related like terminal buildings, parking etc.,
Non-Aviation use like commercial, industrial,
residential or recreational
34. 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.