Airport Engineering

Fall Semester

Sept 11 to Jan 12I hear and I forget; I see and I remember; I do and I 

Lecture – 6

CE – 241understandChinese Proverb 1

Transportation Engineering‐1(NIT‐SCEE‐NUST)

Sequence

– Airport Obstruction

– Imaginary surfacesImaginary surfaces

– Height of object in approach area

– Turning zone

2Transportation Engineering‐1(NIT‐SCEE‐

NUST)

What is the Issue?What is the Issue?

Evaluates the effect of the construction or alteration on operating procedures

• Determines the potential hazardous effect of the proposed t ti lt ti i i ticonstruction or alterations on air navigation

• Identifies mitigating measures to enhance safe air navigation

• Charts new man‐made or natural objects• Charts new man made or natural objects. 

FAR Part 77 allows the “FAA to identify potential aeronautical y phazards in advance thus preventing or minimizing the adverse impacts to the safe and efficient use of navigable airspace”

Zoning lawsZoning laws

• Height zoningHeight zoning

• Land use zoning : Governs type of development These are classified asdevelopment. These are classified as

Closely related like terminal building, parking etc

N i i lik i l i d i lNon aviation use, like commercial, industrial, recreational, etc

Airport ObstructionAirport Obstruction

Divided into following categoriesDivided into following categories

Imaginary surfaces:

• These are the established surfaces in relation to theThese are the established surfaces in relation to the airport and to each runway above which no obstruction should project.p j

• Size of imaginary surfaces depends upon the category of each runway strip and type of approach planned for that runway

Objects with actual heights

Imaginary surfaceImaginary surface

• Approach surfacesApproach surfaces

• Conical surface

• Horizontal surfaceHorizontal surface

• Take off climb surface

• Transitional surface• Transitional surface

Imaginary SurfaceImaginary Surface

FAR specifications for all runway approachesp y ppLength of primary surface 200 ft from end of runway

Horizontal surface elevation 150 ft above runway elevation

Conical surface width 4000 ft

Conical surface slope 20 to 1

Approach surface transitional surface 5000 ftApproach surface transitional surface width

5000 ft

Transitional surface slope 20 to 1

Imaginary SurfaceImaginary Surface

• Approach surfaceApproach surface

Length of horizontal Longitudinal upgrade

P j ti f f i i %Projection of surfaces in m in %

ILS Non ILS ILS Non ILS

A 15000 3000 2 2.5

B 15000 3000 2 2.5

C 15000 3000 2 3.3

D ‐ 2200 ‐ 4D 2200 4

Imaginary SurfaceImaginary Surface

• Approach surfaceApproach surface

Width near the end of runway (in m)

Divergence of sides (in %)(in m)

Projection of surfaces in m in %

ILS Non ILS ILS Non ILS

A 300 150 15 10

B 300 150 15 10

C 300 150 15 10

D ‐ 80 ‐ 10

E ‐ 80 ‐ 10

Take off climb surfaceTake off climb surface

• Similar to the approach surfaceSimilar to the approach surface

• Provided at the take off end of runway

id l i h• Trapezoidal in shape

Take off climb surfaceTake off climb surface

A B C D E

Width near the end of runway in m

180 180 180 80 60

Divergence of sides

12.5 % 12.5 % 12.5 % 10 % 10 %

Length of l i di l

15000 15000 15000 2500 1600longitudinal projection in m

Longitudinal 2 % 2 % 2 % 4 % 5 %Longitudinal upgrade

2 % 2 % 2 % 4 % 5 %

Horizontal surfaceHorizontal surface

• Extends from upper edge of transition surfaceExtends 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 h i l h h 1500having runways length more than 1500 m)above elevation of airport reference point.

Horizontal surfaceHorizontal surface

• The shape of HIS may or may not be circularThe shape of HIS may or may not be circular.

• The radius of outer limit measured from the ARPARP.

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

• Structures having height above Outer HS are not permitted.

Transition surfaceTransition surface

• Trapezoidal in shapeTrapezoidal in shape

• Extends along the   landing  strip

Sl d d d h S• Slopes upwards and outwards to the Inner HS

Conical surfaceConical surface

• Extends upwards and outwards from outer HSExtends upwards and outwards from outer HS to a point which is at some height above the horizontal surfacehorizontal surface.

• Circular in shape

Runway code Side slope transitional surface

% of conical surface

Height of outer or upper circular edge

Radius of inner circular edge conical surfacesurface circular edge  

of the conical surface  above HS in m

conical surface with ARP in m

A 14.3 5.0 100 4000

B 14.3 5.0 100 4000

C 14.3 5.0 75 4000

D 20.0 5.0 55 2500

20 0 0 3 2000E 20.0 5.0 35 2000

C ti fCross sections of Imaginary surfaces 

Objects with actual heightsObjects with actual heights

• Any object which exceeds certain limitingAny object which exceeds certain limiting height above the ground is considered to be an obstruction to the air navigationan obstruction to the air navigation.

• Any object within 4.5 km distance from the runway end is considered as an obstruction ifrunway end is considered as an obstruction if its actual height is more than 30 m above the ground or above the level of approach end ofground or above the level of approach end of runway whichever is higher. 

Objects with actual heights (Cont’d)Objects with actual heights (Cont d)

• Any object which is located beyond of 4.5 km y j ydistance from the runway end is considered as an obstruction if its height above 30 m increases by more than 7 5 m for each additional 1 5mmore than 7.5 m for each  additional 1.5m distance from the runway end or if it exceeds 75m within 15 km distance from the runway from th dthe runway end. 

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

Runway clear zoneRunway clear zone

• Provided after runway end starting at 60mProvided after runway end starting at 60m from the end within approach area

• Length determined by approach surface• Length determined by approach surface attaining a height of 30m

Runway clear zoneRunway clear zoneType of runway W1 (m) W2 (m) L (m)

Instrumental  300 525 750runway

Non instrumental runway

•Visibility as low as 1.25 km

300 435 510

•Visibility greater  150 303 510than 1.25 m

Approach for utility 150 240 300

Visual approach for  150 210 300pplarger than utility

Visibility approach for utility

75 135 300

Runway clear zone/ protection zone

Runway Clear Zone

Runway clear zone/ protection zone

y

RunwayW1

W2

60 m

L

Approach Area

Turning ZoneTurning Zone

• Used in case of emergences for turning aircraftg g• Any object located within a distance of 4.5 km from the ARP is considered as an obstruction if its height exceeds 51m above the ground or theheight exceeds 51m above the ground or the established airport elevation whichever is more

• Any object which is located beyond a distance ofAny object which is located beyond a distance of 4.5 km from the ARP considered as  an obstruction if its height exceeds 51m plus 30m for each additional 1 5km distance from ARP or iffor each additional 1.5km distance from ARP or if it exceeds 150 m within a distance of 15km from ARP

Also If penetrates the enroute obstacle clearance area (includes turn and termination areas of federal airways)

Example ProblemThe end of a precision runway at San Bernardo Airport is located

3,000 ft. from a newly constructed elevated Light Rail Transit(LRT) line as shown in the Figure.(LRT) line as shown in the Figure.

a) Is the pantograph pole an obstruction to navigation? Explain.

b) Suggest alternatives to use Runway 34 if this one cannot berelocated.

ProblemProblem

• Sketch below shows location of a tower proposed by anewly launched mobile phone service providercompany in the vicinity of an airport. Airport referencecode is 3C and the only runway is 1380 m long and 30y y gm wide. There are no stop ways. The height of theproposed tower is 25 m. Considering visual approachrunway, check up whether the proposed tower is any p p pobstruction or otherwise. Reference point for elevationand coordinate system is in the middle centre of therunway. You may assume all points on the runway stripy y p y pand proposed location of tower at the same elevation.

• Use figure : 4.5 / 4.9Use Table : 4.11